ﺍﻟﻌﺭﺒﻴﺔ ﺍﻟﺨﻠﻴﺞ ﻟﺩﻭل ﺍﻟﺘﻌﺎﻭﻥ ﻤﺠﻠﺱ ﻟﺩﻭل ﺍﻟﺘﻘﻴﻴﺱ  ﻫﻴﺌﺔ 
GCC STANDARDIZATION ORGANIZATION (GSO) 
 
 
 
  
  ﻨﻬﺎﺌﻲ:  ﻤﺸﺭﻭﻉ  
 
  
 
GSO2/1/FDS/…: 2009 
 
 
 
  
 
 
  
 
 
 
ﺇﻋﺩﺍﺩ 
  ﻭﺍﻹﻁﺎﺭﺍﺕ  ﺍﻟﻤﺭﻜﺒﺎﺕ  ﻤﻭﺍﺼﻔﺎﺕ  ﻟﻘﻁﺎﻉ ﺍﻟﺨﻠﻴﺠﻴﺔ  ﺍﻟﻔﺭﻋﻴﺔ ﺍﻟﻔﻨﻴﺔ ﺍﻟﻠﺠﻨﺔ 
 
 
 
 
      ﻗﻴﺎﺴﻴﺔ ﻟﻤﻭﺍﺼﻔﺔ  ﻤﺸﺭﻭﻉ  ﺍﻟﻭﺜﻴﻘﺔ ﻫﺫﻩ           ﻓﺈﻨﻬـﺎ ﻟﺫﻟﻙ ﺒﺸﺄﻨﻬﺎ، ﻭﺍﻟﻤﻠﺤﻭﻅﺎﺕ  ﺍﻟﺭﺃﻱ ﻹﺒﺩﺍﺀ ﺘﻭﺯﻴﻌﻬﺎ  ﺘﻡ ﺨﻠﻴﺠﻴﺔ
               ﻤﺠﻠﺱ ﻤﻥ ﺍﻋﺘﻤﺎﺩﻫﺎ  ﺒﻌﺩ ﺇﻻ ﺨﻠﻴﺠﻴﺔ ﻗﻴﺎﺴﻴﺔ ﻜﻤﻭﺍﺼﻔﺔ  ﺇﻟﻴﻬﺎ ﺍﻟﺭﺠﻭﻉ  ﻴﺠﻭﺯ ﻭﻻ ﻭﺍﻟﺘﺒﺩﻴل،  ﻟﻠﺘﻐﻴﻴﺭ ﻋﺭﻀﺔ
ﺍﻟﻬﻴﺌﺔ ﺇﺩﺍﺭﺓ.  ﺍﻟﺘﻲ ﺒﺎﻟﺴﻴﺎﺭﺍﺕ  ﺍﻟﺨﺎﺼﺔ  ﻟﻠﻤﻠﺤﻘﺎﺕ  ﺍﻟﺘﺭﻜﻴﺏ  ﻭﻁﺭﻴﻘﺔ  ﻤﺘﻁﻠﺒﺎﺕ -   ﺍﻟﺴﻴﺎﺭﺍﺕ
 ﺍﻟﻤﺴﺎﻟﺔ ﺍﻟﺒﺘﺭﻭﻟﻴﺔ  ﺒﺎﻟﻐﺎﺯﺍﺕ  ﺘﻌﻤل 
Motor Vehicles – Requirements & Installation of Components 
in Motor Vehicles using Liquefied Petroleum Gases  (LPG)  ﺘﻘﺩﻴﻡ  
ﺍﻷ ﻋﻀﻭﻴﺘﻬﺎ  ﻓﻲ ﺘﻀﻡ ﺇﻗﻠﻴﻤﻴﺔ ﻫﻴﺌﺔ ﺍﻟﻌﺭﺒﻴﺔ ﺍﻟﺨﻠﻴﺞ ﻟﺩﻭل ﺍﻟﺘﻌﺎﻭﻥ ﻤﺠﻠﺱ ﻟﺩﻭل ﺍﻟﺘﻘﻴﻴﺱ ﻫﻴﺌﺔ  ﺠﻬﺯﺓ
 ﺍﻟﻘﻴﺎﺴﻴﺔ ﺍﻟﻤﻭﺍﺼﻔﺎﺕ  ﺇﻋﺩﺍﺩ ﺍﻟﻬﻴﺌﺔ ﻤﻬﺎﻡ ﻭﻤﻥ ، ﺍﻟﻌﺭﺒﻴﺔ ﺍﻟﺨﻠﻴﺞ ﺩﻭل ﻓﻲ ﻭﺍﻟﻤﻘﺎﻴﻴﺱ  ﻟﻠﻤﻭﺍﺼﻔﺎﺕ  ﺍﻟﻭﻁﻨﻴﺔ
 ﻤﺘﺨﺼﺼﺔ  ﻓﻨﻴﺔ ﻟﺠﺎﻥ ﺒﻭﺍﺴﻁﺔ ﺍﻟﺨﻠﻴﺠﻴﺔ  . 
 
 ﺍﻟﻔﻨﻴﺔ ﺍﻟﻠﺠﻨﺔ ﻋﻤل ﺒﺭﻨﺎﻤﺞ ﻀﻤﻥ ﺍﻟﻌﺭﺒﻴﺔ ﺍﻟﺨﻠﻴﺞ ﻟﺩﻭل ﺍﻟﺘﻌﺎﻭﻥ ﻤﺠﻠﺱ ﻟﺩﻭل ﺍﻟﺘﻘﻴﻴﺱ ﻫﻴﺌﺔ ﻗﺎﻤﺕ ﻭﻗﺩ
ﺭﻗﻡ2-1  "ﺍ ﺍﻟﺨﻠﻴﺠﻴﺔ  ﺍﻟﻔﻨﻴﺔ ﻭﺍﻹﻁﺎﺭﺍﺕﺍﻟﻠﺠﻨﺔ  ﺍﻟﻤﺭﻜﺒﺎﺕ  ﻤﻭﺍﺼﻔﺎﺕ  ﻟﻘﻁﺎﻉ ﻟﻔﺭﻋﻴﺔ "   ﺒﺈﻋﺩﺍﺩ  ﺍﻟﻤﻭﺍﺼﻔﺔ  
ﺭﻗﻡ " 2009 …… /FDS/1/2 GSO "  ﺍﻟﺴﻴﺎﺭﺍﺕ - ﺍﻟﺨﺎﺼﺔ  ﻟﻠﻤﻠﺤﻘﺎﺕ  ﺍﻟﺘﺭﻜﻴﺏ  ﻭﻁﺭﻴﻘﺔ  ﻤﺘﻁﻠﺒﺎﺕ  
 ﺒﺎﻟﻐﺎﺯﺍﺕ  ﺘﻌﻤل ﺍﻟﺘﻲ ﺍﻟﻤﺴﺎﻟﺔﺒﺎﻟﺴﻴﺎﺭﺍﺕ  ﺍﻟﺒﺘﺭﻭﻟﻴﺔ  "  ﺒﺈﻋﺩﺍﺩ  ﻗﺒل ﻤﻥ ﺍﻟﺨﻠﻴﺠﻴﺔ  ﺍﻟﻘﻴﺎﺴﻴﺔ ﺍﻟﻤﻭﺍﺼﻔﺔ  ﻫﺫﻩ 
ﺍﻟﺒﺤﺭﻴﻥ  ﺇﻋﺩﺍﻤﻤﻠﻜﺔ  ﺘﻡ ﻭﻗﺩ  ﻭﺍﻟﺩﻭﻟﻴﺔ  ﻭﺍﻷﺠﻨﺒﻴﺔ  ﺍﻟﻌﺭﺒﻴﺔ ﺍﻟﻘﻴﺎﺴﻴﺔ ﺍﻟﻤﻭﺍﺼﻔﺎﺕ  ﺍﺴﺘﻌﺭﺍﺽ  ﺒﻌﺩ ﺍﻟﻤﺸﺭﻭﻉ  ﺩ
ﺍﻟﺼﻠﺔ ﺫﺍﺕ ﺍﻟﻤﺭﺠﻌﻴﺔ  ﻭﺍﻟﻤﺅﻟﻔﺎﺕ  . 
    
 ﺍﻟﻤﻭﺍﺼﻔﺔ  ﻫﺫﻩ ﺍﻋﺘﻤﺩﺕ  ﻭﻗﺩ  ﺨﻠﻴﺠﻴﺔ ﻓﻨﻴﺔ ﻜﻼﺌﺤﺔ    ﺭﻗﻡ ﺍﻟﻬﻴﺌﺔ ﺇﺩﺍﺭﺓ ﻤﺠﻠﺱ ﺍﺠﺘﻤﺎﻉ ﻓﻲ              
      )          ( ﺒﺘﺎﺭﻴﺦ ﻋﻘﺩ ﺍﻟﺫﻱ ،/      /       ﺍ  ، ﻫـ          ﻟﻤﻭﺍﻓﻕ/      /       ﻡ  . 
 
Foreword 
 
Standardization Organization for GCC (G SO) is a regional Organization which 
consists of the National Standards Bodi es of GCC member States. One of GSO 
main functions is to issue Gulf St andards /Technical regulation through 
specialized technical committees (TCs). 
 
GSO through the technical pr ogram of co mmittee TC No . 2-1 "  The Gulf 
technical Subcommittee for vehicles and tyres standards " has prepared this 
Standard .  The Draft Standard has b een prepared by Kingdom Of Bahrain .  
 
 The draft Standard has been prepared  based on relevant ADMO, International 
and National foreign Sta ndards and references. 
 
This standard has been approved as Gulf  Standard by GSO Board of Directors in 
its meeting No..../....  …….held on    /    /   /  H ,  /    /   G  
Motor Vehicles – Requirements & In stallation of Components in 
Motor Vehicles using Liquefied Petroleum Gases  (LPG)  
 
 
 
CONTENTS 
 
REGULATION Page 
 
1. Scope ....................................................................................................................... ..............5 
 2.    Complementary  References  ……………………………………………………………… 5  3. Definition and classification of components .........................................................................5  
PART 1 
 
 4. Markings.................................................................................................................... ..........11 
 5. Specifications regarding the various 
components of the LPG equipment.....................................................................................11 
  
PART II 
 
6. Definitions ................................................................................................................. ..........21 
  7. Requirements for the installation of specific 
equipment for the use of liquefied petroleum gases in the propulsion sy stem of a vehicle ........................................................................21 
  
ANNEXES 
 
Annex 1
 - Essential characteristic s of the vehicle, engine and LPG-related equipment  
 
 
Annex 2  - Not allocated  
 
Annex 3  - Provisions regarding the approva l of LPG container accessories 
 Annex 4
 - Provisions regarding the approval of the fuel pump 
 Annex 5
 - Provisions regarding the a pproval of the LPG filter unit 
 GSO STANDARD                                                                     GSO  /    
 
 4Annex 6  - Provisions regarding the approval of the pressure re gulator and the vaporizer 
 
Annex 7  - Provisions regarding the approval of th e shut-off valve, the non-return valve, 
the gas-tube pressure relief valve and the service coupling 
 
Annex 8  - Provisions regarding the approval of flexible hoses with couplings 
 
Annex 9  - Provisions regarding the approval of the filling unit 
 Annex 10
 - Provisions regarding the approval of LPG containers 
 Annex 11
 - Provisions regarding the approval of gas injection devices, or gas mixing 
pieces, or injectors and the fuel rail 
 
Annex 12  - Provisions regarding the approval of the gas dosage unit when not combined 
with the gas injection device(s) 
 Annex 13
 - Provisions regarding the approval of the pressure a nd/or temperature sensor 
 
Annex 14  - Provisions regarding the approva l of the electr onic control unit 
 Annex 15
 - Test procedures 
 Annex 16
 - Provisions regarding LPG identification mark for M 2 and M 3 category vehicles 
 Annex 17
 - Provisions regarding identifica tion mark for service couplings 
 
Annex 18  - Consolidated Resolution on the Cons truction of Vehicles (R.E.3), (document 
TRANS/WP.29/78/Rev.1/Amend.2, as last amended by Amend.4)) 
 
 
   
 
    GSO STANDARD                                                                     GSO  /    
 
 
 51. SCOPE 
 
This Regulation applies to: 
 
1.1. Part I. Approval of specific equipmen t of motor vehicles using liquefied 
petroleum gases in their propulsion system; 
 1.2. Part II. Approval of a vehicle fitted with specific equipment for the use of 
liquefied petroleum gases in its pr opulsion system with regard to the 
installation of such equipment. 
 
2.                    COMPLEMENTARY REFERENCES 
 
2.1 GSO 48 / 1984 “ Motor Vehicles  Conformity Certificate” 
  
 
3. DEFINITION AND CLASSIFICATION OF COMPONENTS 
 
LPG components for use in vehicles shall be  classified with regard to the maximum 
operating pressure and function, according to Figure 1. 
 
Class 1  High pressure parts including tu bes and fittings c ontaining liquid LPG 
at vapour pressure or increased vapour pressure up to 3,000 kPa. 
 
Class 2  Low pressure parts including t ubes and fittings c ontaining vaporized 
LPG with a maximum operating pre ssure below 450 kPa and over 20 
kPa above atmospheric pressure. 
 
Class 2A Low pressure parts for a limite d pressure range including tubes and 
fittings containing vaporized LPG w ith a maximum operating pressure 
below 120 kPa and over 20 kPa above atmospheric pressure. 
 
Class 3  Shut-off valves and pressure re lief valves, when operating in the liquid 
phase. 
 
LPG components designed for a maximum operating pressure below 20 kPa above 
atmospheric pressure are not subjected to this Regulation. 
 
A component can consist of several parts, ea ch part classified in his own class with 
regard to maximum operating pressure and function. GSO STANDARD                                                                     GSO  /    
 
 6Figure 1 : 
 
Classification with regard to maxi mum operating pressure and function 
3.1. "Pressure " means relative pressure versus  atmospheric pressure, unless 
otherwise stated. GSO STANDARD                                                                     GSO  /    
 
 
 7 
3.1.1. "Service pressure " means the settled pressure at a uniform gas temperature of 
15 °C. 
 
3.1.2. "Test pressure " means the pressure to which the component is subjected during 
the approval test. 
 3.1.3. "Working pressure
" means the maximum pressure to which the component is 
designed to be subjected and on the basi s of which its strength is determined. 
 3.1.4. "Operating pressure
" means the pressure under normal operating conditions. 
 
3.1.5. "Maximum operating pressure " means the maximum pressure in a component 
which might arise during operation. 
 
3.1.6. "Classification pressure " means the maximum allowable operating pressure in a 
component according to its classification. 
 3.2. "Specific equipment
" means: 
 
(a) the container, 
(b) the accessories fitted to the container, 
(c) the vaporizer/pressure regulator,  (d) the shut-off valve, (e) the gas injection device or injector or gas mixing piece, 
(f) the gas dosage unit, either separate or combined with the gas injection 
device, 
(g) flexible hoses, (h) filling unit, (i) non-return valve, (j) gas-tube pressure relief valve, (k) filter unit, 
(l) pressure or temperature sensor, 
 (m) fuel pump, 
(n) service coupling, (o) electronic control unit, 
 (p) fuel rail,  (q) pressure relief device;  GSO STANDARD                                                                     GSO  /    
 
 83.3. "Container " means any vessel used for the stor age of liquefied petroleum gas; 
 
3.3.1. A container can be: 
 
(i) a standard cylindrical container with  a cylindrical shell, two dished ends 
either torispherical or ellipt ical and the required openings; 
(ii) a special container: other containers  than standard cylindrical containers.  
The dimensional characteristics are given in Annex 10, Appendix 5; 
 3.3.2.  "All-composite container
" means a container made only of composite materials 
with a non metallic liner. 
 
3.3.3.  "Batch of containers " means a maximum of 200 cont ainers of the same type 
produced consecutively on the same production line." 
 3.4.  "Type of container
" means containers which do not differ in respect to the 
following characteristics as  specified in Annex 10: 
 
(a) the trade name(s) or trade mark(s), 
(b) the shape (cylindrical, special shape), (c) the openings (plate fo r accessories/metal ring), 
(d) the material, (e) the welding process (in ca se of metal containers), 
(f) the heat treatment (in ca se of metal containers), 
(g) the production line, 
(h) the nominal wall thickness, (i) the diameter (j) the height (in case of special containers) 
 
3.5. "Accessories fitted to the container
" means the following equipment which may 
be either separate or combined: 
 
(a) 80 per cent stop valve 
(b) level indicator (c) pressure relief valve (d) remotely controlled service valve with excess flow valve 
(e) fuel pump 
(f) multivalve (g) gas-tight housing (h) power supply bushing (i) non-return valve 
 (j) pressure relief device  
3.5.1. "80 per cent stop valve
" means a device that limits the filling at maximum 
80 per cent of the capacity  of the container; GSO STANDARD                                                                     GSO  /    
 
 
 9 
3.5.2. "Level indicator " means a device to verify the le vel of liquid in the container; 
 
3.5.3. "Pressure relief valv e (discharge valve) " means a device to limit the pressure 
build-up in the container; 
 
3.5.3.1. "Pressure relief device"  means a device aimed to protect the container from 
burst which can occur in case of fi re, by venting the LPG contained; 
 3.5.4. "Remotely controlled service valve with excess flow valve
" means a device 
which allows the establishment and interruption of LPG supply to the 
evaporator/pressure regulator; remotely controlled means that the service valve is controlled by the electronic control unit;  when the engine of the vehicle is not 
running the valve is closed; an excess fl ow valve means a de vice to limit the 
flow of LPG; 
 
3.5.5. "Fuel pump
" means a device to establish the su pply of liquid LPG to the engine 
by increasing the pressure of the contai ner with the fuel pump supply pressure; 
 
3.5.6. "Multivalve " means a device consisting of all or part of the accessories 
mentioned in paragraphs 3.5.1. to 3.5.3. and 3.5.8.; 
 3.5.7. "Gas-tight housing
" means a device to protect the accessories and to vent any 
leakages to the open air; 
 3.5.8. power supply bushing (fuel pump/ actuators/fuel level sensor); 
 
3.5.9. "Non-return valve
" means a device to allow the flow of liquid LPG in one 
direction and to prevent the flow of liquid LPG in the opposite direction; 
 
3.6. "Vaporizer " means a device intended to vaporize LPG from a liquid to a 
gaseous state; 
 3.7. "Pressure regulator
" means a device intended for reducing and regulating the 
pressure of liquefied petroleum gas; 
 3.8. "Shut-off valve
" means a device to cut off the flow of LPG; 
 
3.9. "Gas-tube pressure relief valve " means a device to prevent the pressure build up 
in the tubes above a pre-set value; 
 
3.10. "Gas injection device or injector or gas mixing piece " means a device which 
establishes the liquid or vaporiz ed LPG to enter the engine; 
 3.11. "Gas dosage unit
" means a device which meters a nd/or distributes the gas flow 
to the engine and can be either comb ined with the gas injection device or GSO STANDARD                                                                     GSO  /    
 
 10separate. 
 
3.12. "Electronic control unit " means a device which controls the LPG demand of the 
engine and cuts off automatically the pow er to the shut-off valves of the LPG-
system in case of a broken fuel supply pi pe caused by an accident, or by stalling 
of the engine; 
  3.13. "Pressure or temperature sensor
" means a device which m easures pressure or 
temperature; 
 
3.14. "LPG filter unit " means a device which filters the LPG, the filter can be 
integrated in other components; 
 3.15. "Flexible hoses
" means hoses for conveying liquefi ed petroleum gas in either a 
liquid or vapour state at  various pressures from one point to another; 
 3.16. "Filling unit
" means a device to allow filling of the container; the filling unit 
can be realised by integration in the 80 per cent stop valve of the container or 
by a remote filling unit at the outside of the vehicle; 
 
3.17. "Service coupling " means a coupling in the fuel line between the fuel container 
and the engine.  If a mono-fuel vehicle is out of fuel the engine can be operated 
by means of a service fuel container which can be coupled to the service 
coupling; 
 3.18. "Fuel rail
" means a pipe or duct that conne cts the fuel injection devices; 
 
3.19. "Liquefied petroleum gas (LPG) " means any product esse ntially composed of 
the following hydrocarbons: 
propane, propene (propylene), normal butane, isobutane, isobutylene, butene 
(butylene) and ethane. 
 
European Standard EN 589:1993 specifies requirements and methods of test for 
automotive LPG as marketed and delivered  in the countries of the members of 
CEN (European Committee for Standardization). GSO STANDARD                                                                     GSO  /    
 
 
 11PART I 
 
APPROVAL OF SPECIFIC EQUIPMENT OF MOTOR VEHICLES USING 
LIQUEFIED PETROLEUM GASES IN THEIR PROPULSION SYSTEM 
 
  
4. MARKINGS 
 
4.1. All components submitted for approval shall bear the trade name or mark of the 
manufacturer and the type; and for non-metallic components also the manufacturing month and year; this ma rking shall be clearly legible and 
indelible. 
 
4.2. All equipment shall have a space large enough to accommodate the approval 
mark including the classification of th e component; this space shall be shown 
on the drawings referred to in paragraph 3.2.2. above. 
 4.3 Every container shall also bear a marking plate, welded to it,  with the following 
data clearly legible and indelible: 
 
(a) a serial number; (b) the capacity in litres; (c) the marking "LPG"; (d) test pressure [kPa]; (e) the wording: "maximum degree of filling: 80 %"; 
(f) year and month of approval (e.g. 99/01); (g) approval mark according to paragraph 5.4. (h) the marking "PUMP INSIDE" and a marking identifying the pump when 
a pump is mounted in the container. 
  
5. SPECIFICATIONS REGARDING THE VARIOUS COMPONENTS OF 
THE LPG EQUIPMENT 
 5.1. General provisions 
 
The specific equipment of vehicles usi ng LPG in their propulsion system shall 
function in a correct and safe way. 
 
The materials of the equipment which are in contact with LPG shall be 
compatible with it. 
 
Those parts of equipment whose correct and safe functioning is liable to be 
influenced by LPG, high pressure or vibrations has to be submitted to relevant 
test procedures described in the annexes of this Regulation.  In particular the GSO STANDARD                                                                     GSO  /    
 
 12provisions of paragraphs 5.2. to 5.13. are to be fulfilled. 
 
The installation of LPG-equipment appr oved by this regulation shall comply 
with relevant electromagnetic compatib ility (E.M.C) requirements according to 
Regulation No. 10, 02 series of amendments, or equivalent. 
 
5.2. Provisions regarding containers  
The LPG containers shall be type-appr oved pursuant to the provisions laid 
down in Annex 10 to this Regulation. 
 5.3. Provisions regarding accessori es fitted to the container 
 
5.3.1. The container shall be equipped with the following accessories, which may be 
either separate or combined (multivalve(s)): 
 5.3.1.1. 80 per cent stop valve,  5.3.1.2. level indicator,  5.3.1.3. pressure relief valve (discharge valve),  5.3.1.4. remotely controlled service valve with excess flow valve,  5.3.2. The container may be equipped with  a gas-tight housing, if necessary. 
 
5.3.3. The container may be equipped with a power supply bushing for the sake of 
actuators/LPG fuel pump. 
 
5.3.4. The container may be equipped with a LPG fuel pump inside the container. 
 5.3.5. The container may be equipped with a non-return valve.  5.3.6. The container shall be equi pped with a pressure relief device (PRD).  Devices 
or functions may be approved as PRD being: 
 
(a) A fusible plug (temperatu re triggered) (fuse), or 
(b) A pressure relief valve provided that it complies to paragraph 5.15.8.3., 
or 
(c) A combination of the two above devices, or 
(d) Any other equivalent technical solution, provided that it ensures the same 
degree of performance. 
 5.3.7. The accessories mentioned in paragraphs 5.3.1. to 5.3.6. above shall be type-
approved pursuant to the provisions laid down in: 
 GSO STANDARD                                                                     GSO  /    
 
 
 13 - Annex 3 to this Regulation for ac cessories mentioned in paragraphs 
5.3.1., 5.3.2., 5.3.3. and 5.3.6., 
     
- Annex 4 to this Regulation for accessories mentioned in paragraph 5.3.4., 
 
- Annex 7 to this Regulation for accessories mentioned in paragraph 5.3.5. 
 
5.4. - 5.13. Provisions regarding other components  
The other components, which are shown in Table 1, shall be type approved 
pursuant to the provisions laid down in the annexes which can be determined from the table. GSO STANDARD                                                                     GSO  /    
 
 14Table 1  
 
Paragraph Component Annex 
5.4. Fuel pump 4 
5.5. Vaporizer 1 / 
Pressure regulator 1 / 6 
5.6. Shut-off valves 
Non-return valves Gas-tube pressure relief valves Service couplings 7 
5.7. Flexible hoses 8 
5.8. Filling unit 9 
5.9. Gas injection devices/ Gas mixing piece 3
/ 
or Injectors 11 
5.10. Gas dosage units 2 / 12 
5.11. Pressure sensors Temperature sensors 13 
5.12. Electronic control unit 14 
5.13. LPG filter units 5 
5.14. Pressure relief device 3 
 
1/ Either combined or separate 
2/ Only applicable when the gas dosage actuator is not integrated in the gas 
injection device. 
3/ Applicable only when the operating  pressure of the gas mixing piece 
exceeds 20 kPa (Class 2). 
 
5.15. General design rules regarding components 
 5.15.1. Provisions regarding th e 80 per cent stop valve 
 
5.15.1.1. The connection between th e float and the closing un it of the 80 per cent stop 
valve shall not be deformed under normal conditions of use. 
 
5.15.1.2. If the 80 per cent stop valve of the cont ainer comprises a float, the latter shall 
withstand an outside pressure of 4,500 kPa. 
 5.15.1.3. The closing unit of the device that limits the filling at 80 per cent +0/-5 per GSO STANDARD                                                                     GSO  /    
 
 
 15cent of the capacity of the container, for which the 80 per cent stop valve is 
designed, shall withstand a pressure of 6,750 kPa.  At the cut-off position, the 
filling rate at a differential pressu re of 700 kPa shall not exceed 500 
cm3/minute.  The valve must be tested with all the containers on which it is 
intended to be fitted or the manufactur er must declare by calculation for 
which container types this valve is suitable. 
 5.15.1.4. When the 80 per cent stop valve does not  comprise any float,  it shall not be 
possible to continue filling, after closing-off, at a rate exceeding 500 
cm
3/minute. 
 
5.15.1.5. The device shall bear a permanent ma rking, indicating the container-type for 
which it has been designed, diameter a nd angle, and if applicable mounting 
indication. 
 
5.15.2. Electrical operated devices containing LP G shall, in order to  prevent in case 
of fracture of the component electric sparks on the surface of fracture: 
 (i) be insulated in a manner that no cu rrent is lead through LPG containing 
parts 
(ii) have the electrical sy stem of the device isolated: 
-  from the body -  from the container for the fuel pump. 
Isolation resistance shall be > 10 M Ω. 
 
5.15.2.1. The electrical connections inside th e boot and passengers compartment shall 
comply with insulation class IP 40 according to IEC 529. 
 5.15.2.2. All other electrical connections shall comply with insula tion class IP 54 
according to IEC 529. 
 5.15.2.3. The power supply bushing (fuel pump/actua tors/fuel level sensor) to establish 
an isolated and tight electr ical connection shall be of  a hermetic sealed type. 
 5.15.3. Specific provisions on valves activated  by an electric/external (hydraulic, 
pneumatic) power 
 5.15.3.1. In the case of valves activated by an  electric/external power (e.g. 80 per cent 
stop valve, service valve, shut-off valves , non return valves, gas tube pressure 
relief valve, service coupling), those va lves shall be in "closed" position when 
their power is switched off. 
 5.15.3.2. The power of the fuel pump shall be switched off when th e electronic control 
unit becomes defective or loses power. 
 5.15.4. Heat exchange medium (compatib ility and pressure requirements) GSO STANDARD                                                                     GSO  /    
 
 16 
5.15.4.1. The materials constituting a device wh ich are in contact with the heat 
exchange medium of a device when opera ting shall be compatible with that 
fluid and shall be designed to withst and a pressure of 200 kPa of the heat 
exchange medium.  The material shall meet the prescriptions laid down in Annex 15, paragraph 17. 
 5.15.4.2. The compartment containing the heat exchange medium of the 
vaporizer/pressure regulator  shall be leak proof at  a pressure of 200 kPa. 
 5.15.5. A component consisting of both high pre ssure and low pressure parts shall be 
so designed to prevent a pressure build up in the low pressure part above 2.25 
times the maximum working pressure  for which it has been tested.  
Components connected directly to the ta nk pressure shall be designed for the 
classification pressure of 3,000 kPa.  Venting to the motor compartment or 
outside of the vehicle is not allowed. 
 
5.15.6. Specific provisions to prevent any gas flow  5.15.6.1. The pump shall be so designed that  the outlet pressu re never exceeds 
3,000 kPa, when there is e.g. blocking of  the tubing or not opening of a shut-
off valve.  This can be realized by switching off the pump or by recirculating 
to the container. 
 5.15.6.2. The pressure regulator/vaporizer shall be so designed as to prevent any gas 
flow when the regulator/vaporizer unit is supplied with LPG at a pressure 
≤ 4,500 kPa when the regulator is not operating. 
 5.15.7. Provisions regarding the gas tube relief valve 
 5.15.7.1. The gas-tube pressure relief valve shall be so designe d as to open at a 
pressure 
of 3,200 ± 100 kPa. 
 
5.15.7.2. The gas-tube pressure relief valve shall not have inte rnal leakage up to 
3,000 kPa. 
 5.15.8. Provisions regarding the pressure relief valve (discharge valve) 
 5.15.8.1. The pressure relief valve shall be mounted inside the container or on the 
container, in the area where the fuel is in gaseous state. 
 5.15.8.2. The pressure relief valve shall be so  designed as to op en at a pressure 
of 2,700 ± 100 kPa. 
 GSO STANDARD                                                                     GSO  /    
 
 
 175.15.8.3. The flow capacity of th e pressure relief valve, de termined with compressed 
air at a pressure which is 20 per cent higher than the normal operating-
pressure must be at least 
 
 Q ≥ 10.66 ⋅ A0.82 
 
in which: 
 
Q = flow of air in standard m3/min (100 kPa absolute and temperature of 
15 °C) 
A = exterior surface of the container in m2. 
 
The flow test results must be corrected to standard conditions: 
air pressure of 100 kPa absolu te and temperature of 15 °C. 
 
When the pressure relief valve is consid ered as a pressure relief device, the 
flow shall be at least 17.7 standard m3/min. 
 
5.15.8.4. The pressure relief valve shall not have internal leakage up to 2,600 kPa. 
 
5.15.8.5. The pressure relief device (fuse) shall be designed to open at a temperature of 
120 ± 10 °C. 
 
5.15.8.6. The pressure relief devi ce (fuse) shall be designed  to have, when opened, a 
flow capacity of: 
 
Q ≥ 2.73 ⋅ A 
 
in which: 
 
 Q = flow of air in standard m3/min (100 kPa absolute and temperature of 
15 °C) 
 A = exterior surface of the container in m2. 
 
The flow test must be carried out at  an upstream air pressure of 200 kPa 
absolute, and at temperature of 15 °C. 
  
 The flow test results must be corrected to standard conditions: 
air pressure of 100 kPa absolu te, and temperature of 15 °C. 
 5.15.8.7. The pressure relief device shall be mounted on the container in the gaseous 
zone.  
5.15.8.8. The pressure relief device shall be fitted to the container in such a manner that 
it can discharge into the ga s tight housing, when its presence is prescribed. 
 GSO STANDARD                                                                     GSO  /    
 
 185.15.8.9. The pressure relief device (fuse) shall be tested according to the provisions 
described in Annex 3, paragraph 7. 
 
5.15.9. Power dissipation of the fuel pump 
At minimum fuel level whereby the engi ne is still operating the heat build-up 
by the fuel pump(s) should never cause  the pressure relief valve to open. 
 5.15.10. Provisions regarding the filling unit  5.15.10.1. The filling unit shall be equipped with at least one soft-seated non-return 
valve, and it shall not be dismountable by design. 
 5.15.10.2. The filling unit shall be prot ected against contamination. 
 
5.15.10.3. The design and dimensions of the c onnecting area of the filling unit must 
comply with those in the figures in Annex 9.  
 
 The filling unit shown in Figure 5 is onl y applicable for motor vehicles of 
categories M
2, M 3, N2, N3 and M 1 having a maximum total mass > 3,500 kg. 1 
 
5.15.10.4. The filling unit shown in Figure 4 ma y also apply for motor vehicles of 
categories M 2, M 3, N2, N3 and M 1 having a maximum total mass > 3,500 kg.  
 
5.15.10.5. The outside filling unit is connected to the container by a hose or pipe. 
 
5.15.10.6. Specific provisions regarding the light  vehicle Euro filling unit (Annex 9 – 
Figure 3): 
 
5.15.10.6.1. The dead volume between the front sealing surface and the front of the non-
return valve shall not exceed 0.1 cm3; 
 5.15.10.6.2. The flow through the connect or at a pressure difference of 30 kPa shall be at 
least 60 litres/min, if tested with water. 
 
5.15.10.7. Specific provisions regarding the h eavy-duty vehicle Euro filling unit 
(Annex 9 – Figure 5): 
 
5.15.10.7.1. The dead volume between the front sealing surface and the front of the non-
return valve shall not exceed 0.5 cm3; 
 
5.15.10.7.2. The flow through the filling unit, with  the non-return valve mechanically 
opened, at a pressure difference of 50 kPa shall be at le ast 200 litres/min, 
when tested with water. 
 
                                                 
1 - For the purpose of this regulation, refer to the definition of M & N category mentioned in Annex 18 
(Consolidated Resolution on the Construction of Vehicles (R.E.3), (document 
TRANS/WP.29/78/Rev.1/Amend.2, as last amended by Amend.4)). GSO STANDARD                                                                     GSO  /    
 
 
 195.15.10.7.3. The Euro filling unit shall comply w ith the impact test as described in 
paragraph 7.4. 
 
5.15.11. Provisions regarding the level indicator 
 5.15.11.1. The device to verify the le vel of liquid in the containe r shall be of an indirect 
type (for example magnetic ) between the inside  and outside of the container.  
If the device to verify the level of liqui d in the container is  of a direct type, 
the electric power connections should meet IP54 specifications according to IEC EN 60529:1997-06. 
 5.15.11.2. If the level indicator of  the container comprises a float, the latter shall 
withstand an outside pressure of 3,000 kPa. 
 
5.15.12. Provisions regarding the gas tig ht housing of the container. 
 5.15.12.1. The gas-tight housing outlet shall have a total free-cross-section of at least 
450 mm
2. 
 
5.15.12.2. The gas-tight housing shall be leak-pr oof at a pressure of 10 kPa with the 
aperture(s) closed off, maximu m allowed leak rate of 100 cm3/h vapour and 
show no permanent deformation. 
 
5.15.12.3. The gas-tight housing shall be designed  to withstand a pressure of 50 kPa. 
 
5.15.13. Provisions regarding the remotely cont rolled service valv e with excess flow 
valve. 
 5.15.13.1. Provisions regarding the service valve  5.15.13.1.1. In case the service valve is comb ined with a LPG fuel supply pump, 
identification of the pump must be realised by the marking "PUMP INSIDE" 
and the identification of the pump eith er on the marking plate of the LPG 
container or on the multivalve if presen t. Electrical connections inside the 
LPG container shall comply with insulation class IP 40 according to IEC 529. 
 
5.15.13.1.2. The service valve shall withstand a pressure of 6,750 kPa in the open and 
closed position. 
 5.15.13.1.3. The service valve shall not,  at the shut-off position, allo w an internal leak rate 
in the flow direction.  There may be  leak in the back flow direction. 
 5.15.13.2. Provisions regarding the excess flow valve 
 5.15.13.2.1. The excess flow valve shall be mounted inside the container.  GSO STANDARD                                                                     GSO  /    
 
 205.15.13.2.2. The excess flow valve shall be designed with a bypass to allow for 
equalization of pressures. 
 
5.15.13.2.3. The excess flow valve shall cut off at a pressure differenc e over the valve of 
90 kPa.  At this pressure differen ce the flow shall not exceed 8,000 cm3/min. 
 
5.15.13.2.4. When the excess flow valve is at cut-off position, the flow through the 
by-pass shall not exceed 500 cm3/min. at a differential pressure of 700 kPa. 
  
 
 GSO STANDARD                                                                     GSO  /    
 
 
 21PART II 
 
APPROVAL OF A VEHICLE 
FITTED WITH SPECIFIC EQUIPMENT FOR THE USE 
OF LIQUIFIED PETROLEUM GASES IN ITS PROPULSION SYSTEM 
WITH REGARD TO THE INSTALLA TION OF SUCH EQUIPMENT 
 
  
6. DEFINITIONS 
 
6.1. For the purposes of Part II of this Regulation: 
 6.1.1. "Approval of a vehicle
" means the approval of a vehicle type with regard to 
the installation of its specific equipment for the use of liquefied petroleum 
gases in its propulsion system; 
 
6.1.2. "Vehicle type " means a vehicle or a family of  vehicles fitted with specific 
equipment for the use of LPG in its  propulsion system, which do not differ 
with respect to the following conditions: 
 6.1.2.1. the manufacturer;  6.1.2.2. the type designation estab lished by the manufacturer; 
 6.1.2.3. the essential aspects of design and construction;  6.1.2.3.1. chassis/floor pan (obvious a nd fundamental differences); 
 6.1.2.3.2. installation of the LPG equipment ( obvious and fundamental differences). 
 
  
7. REQUIREMENTS FOR THE IN STALLATION OF SPECIFIC 
EQUIPMENT FOR THE USE OF LIQUEFIED PETROLEUM GASES 
IN THE PROPULSION SYSTEM OF A VEHICLE 
 
7.1. General 
 
7.1.1. The LPG equipment as installed in the vehicle shall function in such a 
manner that the maximum operating pressure for which it has been designed and approved cannot be exceeded. 
 7.1.2. All parts of the system shall be type  approved for individual parts pursuant 
to Part I of this Regulation. 
 GSO STANDARD                                                                     GSO  /    
 
 227.1.3. The materials used in the system sh all be suitable for use with LPG. 
 
7.1.4. All parts of the system shall be fastened in a proper way.  7.1.5. The LPG-system shall show no leaks.  7.1.6. The LPG-system shall be installed such that is has the best possible 
protection against damage, such as  damage due to moving vehicle 
components, collision, grit or due to the loading or unloading of the vehicle or the shifting of  those loads. 
 7.1.7. No appliances shall be c onnected to the LPG-system other than those strictly 
required for the proper operation of the engine of the motor vehicle. 
 
7.1.7.1. Notwithstanding the pr ovisions of paragraph 7.1.7., motor vehicles of 
categories M
2, M 3, N 2, N 3 and M 1 having a maximum total mass > 3500 kg 
may be fitted with a heating system to heat the passenger compartment 
which is connected to the LPG-system. 
 
7.1.7.2. The heating system referred to in pa ragraph 7.1.7.1. shall be permitted if, in 
the view of the technica l services responsible for conducting type approval, 
the heating system is adequately prot ected and the required operation of the 
normal LPG-system is not affected. 
 7.1.7.3. Notwithstanding the pr ovisions of paragraph 7.1.7., a mono-fuel vehicle 
without limp-home system may be equi pped with a servic e coupling in the 
LPG-system. 
 7.1.7.4. The service coupling referred to in pa ragraph 7.1.7.3. shall be permitted if, in 
the view of the technica l services responsible for conducting type approval, 
the service coupling is adequately prot ected and the requir ed operation of the 
normal LPG-system is not affected.  The service coupling must be combined 
with a separate gas-tight non-return valve whereby it is only possible to 
operate the engine.  
 7.1.7.5. Mono-fuel vehicles installed with a service coupling shall carry a sticker 
near the service coupling as specified in Annex 17. 
 7.1.8. Identification of LPG-fuelled M
2 and M 3 category vehicles. 
 
7.1.8.1. Vehicles of category M 2 and M 3 shall carry a plate as  specified in Annex 16. 
 7.1.8.2. The plate shall be installed on the front and rear of the M
2 or M 3 category 
vehicle and on the outside of the door s on the left-hand side for the right 
hand drive vehicles and on the right-hand side fo r the left hand drive 
vehicles. GSO STANDARD                                                                     GSO  /    
 
 
 23 
7.2. Further requirements  7.2.1. No component of the LPG-system, in cluding any protectiv e materials which 
form part of such components, shall project beyond the ex ternal surface of 
the vehicle, with the exception of the filling unit if this does not project more than 10 mm beyond the nominal line of the body panel. 
 7.2.2. With the exception of the LPG fuel container, in no cross section of the 
vehicle any component of the LPG-syst em, including any protective material 
which forms part of such components, may extend beyond the lower edge of the vehicle unless another pa rt of the vehicle, within  a radius of 150 mm is 
situated lower. 
 
7.2.3. No component of the LPG-system sh all be located within 100 mm of the 
exhaust or similar heat source, un less such components are adequately 
shielded against heat. 
 7.3. The LPG-system  7.3.1. An LPG-system shall contain at least the following components:
 
 
7.3.1.1. fuel container; 
 
7.3.1.2. 80 per cent stop valve;  7.3.1.3. level indicator; 
 
7.3.1.4. pressure relief valve;  7.3.1.5. remotely controlled service valve with excess flow valve;  7.3.1.6. pressure regulator and vaporizer, which may be combined;  
7.3.1.7. remotely controlled shut-off valve;  7.3.1.8. filling unit;  7.3.1.9. gas tubes and hoses;  7.3.1.10. gas-carrying connections between  the LPG-system components; 
 7.3.1.11. injector or gas injection device or gas mixing piece;  7.3.1.12. electronic control unit;  GSO STANDARD                                                                     GSO  /    
 
 247.3.1.13. pressure relief device (fuse). 
 7.3.2. The system may also include the following components:
 
 
7.3.2.1. gas-tight housing, covering the accessori es fitted to the fuel container; 
 
7.3.2.2. non-return valve;  7.3.2.3. gas tube pressure relief valve; 
 
7.3.2.4. gas dosage unit;  7.3.2.5. LPG filter unit;  7.3.2.6. pressure or temperature sensor;  
7.3.2.7. LPG fuel pump;  7.3.2.8. power supply bushing for the containe r (actuators/fuel pump/fuel level 
sensor); 
 7.3.2.9. service coupling (mono-fuel vehi cles only & no limp-home system); 
 7.3.2.10. fuel selection system and electrical system;  7.3.2.11. fuel rail. 
 
7.3.3. The container fittings referred to  in paragraphs 7.3.1.2. to 7.3.1.5. may be 
combined. 
 
7.3.4. The remotely controlled shut-off valve referred to in paragraph 7.3.1.7. may 
be combined with the pre ssure regulator/vaporizer. 
 
7.3.5. Additional components required for th e effective operation of the engine 
may be installed in that part of the LPG-system where the pressure is less 
than 20 kPa. 
 7.4. Installation of th e fuel container 
 7.4.1. The fuel container shall be permanently  installed in the ve hicle and shall not 
be installed in the engine compartment. 
 7.4.2. The fuel container shall be installed in the correct position, according to the 
instructions from the container manufacturer. 
 7.4.3. The fuel container shall be installed such that there is no metal to metal GSO STANDARD                                                                     GSO  /    
 
 
 25contact, other than at the perman ent fixing points of the container. 
 
7.4.4. The fuel container shall have perman ent fixing points to secure it to the 
motor vehicle or the container shall be secured to the motor vehicle by a 
container frame and container straps. 
 7.4.5. When the vehicle is ready for use the fuel container shall not be less than 
200 mm above the road surface. 
 7.4.5.1. The provisions of paragraph 7.4.5. sh all not apply if the container is 
adequately protected, at the front and th e sides and no part of the container is 
located lower than this  protective structure. 
 
7.4.6. The fuel container(s) must be mount ed and fixed so that the following 
accelerations can be absorbed (wit hout damage occurring) when the 
containers are full: 
  Vehicles of categories M
1 and N 1: 
 
 (a) 20 g in the direction of travel 
 (b)   8 g horizontally perpendicu lar to the direction of travel 
 
 Vehicles of categories M 2 and N 2: 
 
 (a) 10 g in the direction of travel 
 (b)   5 g horizontally perpendicu lar to the direction of travel 
 
 Vehicles of categories M 3 and N 3: 
 
 (a) 6.6 g in the direction of travel 
 (b) 5 g horizontally perpendicula r to the direction of travel 
 
A calculation method can be used inst ead of practical testing if its 
equivalence can be demonstrated by the applicant for approval to the 
satisfaction of the technical service. 
 
7.5. Further requirements to the fuel container  7.5.1.  If more than one LPG container is connected to a single delivery tube each 
container shall be fitted with a non-return valve installed downstream of the remotely controlled service valve a nd a tube pressure relief valve shall 
be installed in the delivery tube, down stream of the non-return valve.  An 
adequate filter system has to be plac ed upstream of the non-return valve(s) 
to prevent fouling of the non-return valve(s). 
 
7.5.2.  A non-return valve and tube pressure relief valve shall no t be required if GSO STANDARD                                                                     GSO  /    
 
 26the backflow pressure of the remotely controlled service valve in the 
closed position exceeds 500 kPa. In that case the control of the remote ly controlled service valves shall be 
constructed such that it is impossible for more than one remotely controlled valve to be open at any time.  The overlap time to allow switching is limited to two minutes. 
 7.6.  Accessories to the fuel container  7.6.1.  Remotely controlled service valve with excess flow valve on the container
 
 
7.6.1.1. The remotely controlled service va lve with excess flow valve shall be 
installed directly on the fuel contai ner, without any intervening fittings. 
 
7.6.1.2. The remotely controlled service va lve with excess flow valve shall be 
controlled such that it is automatically closed when the engine is not 
running, irrespective of the position of the ignition switch, and shall remain 
closed as long as the engine is not running. 
 
7.6.2.  Spring-loaded pressure re lief valve in the container  
 
7.6.2.1. The spring-loaded pressure relief va lve shall be installed in the fuel 
container in such a manner that it is  connected to the vapour space and can 
discharge to the surrounding atmosphe re.  The spring-loaded pressure 
relief valve may discharge into the gas-tight housing if that gas-tight 
housing fulfils the requirem ents of paragraph 7.6.5. 
 
7.6.3.  80 per cent stop valve  
 
7.6.3.1. The automatic filling level limiter sha ll be suitable for the fuel container it 
is fitted to and shall be installed in the appropriate position to ensure that 
the container cannot be filled  to more than 80 per cent. 
 
7.6.4.  Level indicator  
 
7.6.4.1. The level indicator shall be suitable fo r the fuel container it is fitted to and 
shall be installed in the appropriate position. 
 
7.6.5.  Gas-tight housing on the container  
 
7.6.5.1. A gas-tight housing over the contai ner fittings, which fulfils the 
requirements of paragraphs 7.6.5.2. to 7.6.5.5. shall be fitted to the fuel 
container, unless the container is in stalled outside th e vehicle and the 
container fittings are protect ed against dirt and water. 
 
7.6.5.2. The gas-tight housing shall be in open connection with the atmosphere, GSO STANDARD                                                                     GSO  /    
 
 
 27where necessary through a connecting hose and a lead-through. 
 
7.6.5.3. The ventilation opening of the gas- tight housing shall point downwards at 
the point of exit from the motor vehi cle.  However, it shall not discharge 
into a wheel arch, nor shall it be aimed at a heat source such as the exhaust. 
 7.6.5.4. Any connecting hose and lead-throu gh in the bottom of the bodywork of 
the motor vehicle for ventilation of the gas-tight housing shall have a minimum clear opening of 450 mm
2.  If a gas tube, other tube or any 
electrical wiring is inst alled in the connecting hose and lead-through, the 
clear opening shall also  be at least 450 mm2. 
 
7.6.5.5. The gas-tight housing and connecting hoses  shall be gas-tight at a pressure 
of 10 kPa with the apertures closed off, and show no permanent 
deformation, with a maximum allowed leak rate of 100 cm3/h. 
 
7.6.5.6. The connecting hose shall be secure d in a proper way to the gas-tight 
housing and the lead-through to ensure that a gas-tight joint is formed. 
 
7.7.  Gas tubes and gas hoses  
7.7.1.  Gas tubes shall be made of seamless material: either copper or stainless 
steel or steel with co rrosion-resistant coating. 
 
7.7.2.  If seamless copper is used the tube shall be protected by a rubber or plastic 
sleeve. 
 7.7.3.  The outer diameter of gas tubes made of copper shall not exceed 12 mm 
with a wall thickness of at least 0.8 mm,  gas tubes from steel and stainless 
steel shall not exceed 25 mm with, for gas services, an appropriate wall 
thickness. 
 7.7.4.  The gas tube may be made of a non-met allic material if the tube fulfils the 
requirements of this Regulation, paragraph 6.7. 
 7.7.5. The gas tube may be replaced by a gas hose if this hose fulfils the 
requirement of this Regulation, paragraph 6.7. 
 7.7.6. Gas tubes, other than non-metallic gas tubes, shall be secured such that 
they shall not be subjected to vibration or stresses. 
 7.7.7. Gas hoses and non-metallic gas tubes shall be secured such that they shall 
not be subjected to stresses. 
 7.7.8. At the fixing point the gas tube or  hose shall be fitted with a protective 
material. GSO STANDARD                                                                     GSO  /    
 
 28 
7.7.9. Gas tubes or hoses shall not be located at jacking points. 
 7.7.10. At passages the gas tubes or hoses, wh ether or not fitted with a protective 
sleeve, shall be fitted with protective material. 
 7.8. Gas connections between the co mponents of the LPG-system 
 7.8.1. Soldered or welded joints and bite-type compression joints are not 
permitted. 
 7.8.2. Gas tubes shall only be connected by co mpatible fittings with regard to 
corrosion. 
 
7.8.3. Stainless steel tubes shall only be joined by stainless steel fittings. 
 7.8.4. Distributing-blocks shall be made  of corrosion-resistant material. 
 7.8.5. Gas tubes shall be connected by appropr iate joints, for example, two-part 
compression joints in steel tubes and joints with olives tapered on both sides or two flanges in copper tubes.  Gas tubes shall be connected with 
appropriate connections.  Under no circumstances couplings may be used 
whereby the tube will be damaged.  The burst pressure of the mounted couplings shall be the same or higher as specified for the tube. 
 7.8.6. The number of joints shall be limited to a minimum. 
 
7.8.7. Any joints shall be made in lo cations where access is possible for 
inspection. 
 
7.8.8. In a passenger compartment or enclos ed luggage compartment the gas tube 
or hose shall be no longer than reasonably required; this provision is fulfilled when the gas tube or hose does not extend further than from the fuel container to the side of vehicle.  
 7.8.8.1. There shall be no gas-conveying conn ections in the passenger compartment 
or enclosed luggage compar tment with the exception of: 
 (i) the connections on the gas-tight housing; and (ii) the connection between the gas tube or hose and the filling unit if 
this connection is fitted with a sl eeve which is resistant against LPG 
and any leaking gas will be discharg ed directly into the atmosphere. 
 7.8.8.2. The provisions of paragraph 7.8.8. and paragraph 7.8.8.1. shall not apply 
for M
2 or M 3 category vehicles if the gas tubes or hoses and connections 
are fitted with a sleeve which is re sistant against LPG and which has an GSO STANDARD                                                                     GSO  /    
 
 
 29open connection to the atmosphere.  The open end of the sleeve or ducting 
shall be situated at the lowest point. 
 
7.9. Remotely controlled shut-off valve  7.9.1. A remotely controlled shut-off valve shal l be installed in the gas tube from 
the LPG container to the pressure regul ator/vaporizer, as close as possible 
to the pressure re gulator/vaporizer. 
 7.9.2. The remotely controlled shut-off va lve may be incorporated into the 
pressure regulator/vaporizer. 
 7.9.3. Notwithstanding the provis ions of paragraph 7.9.1., the remotely controlled 
shut-off valve may be installed at a lo cation in the engine bay specified by 
the manufacturer of the LPG-system if  a fuel return system is provided 
between the pressure regula tor and the LPG container. 
 
7.9.4. The remotely controlled shut-off valve shall be installed such that the fuel 
supply is cut off when the engine is not  running or, if the vehicle is also 
equipped with another fuel system, wh en the other fuel is selected.  A 
delay of 2 seconds is permitted for diagnostic purposes. 
 7.10. Filling unit  7.10.1. The filling unit shall be secured agai nst rotation and shall be protected 
against dirt and water. 
 7.10.2. When the LPG container is installed in the passenger compartment or an 
enclosed (luggage) compartment, the filling unit shall be located at the 
outside of the vehicle. 
 7.11. Fuel selection system a nd electrical installation 
 7.11.1. The electrical components of the LPG- system shall be protected against 
overloads and at least one  separate fuse shall be  provided in the supply 
cable. 
 7.11.1.1. The fuse shall be installed in a kn own location where it can be reached 
without the use of tools. 
 7.11.2. The electrical power to  LPG-system components which also carry gas may 
not be conducted by a gas tube. 
 7.11.3. All electrical components installed in  a part of the LPG-system where the 
pressure exceeds 20 kPa shall be conn ected and insulated in a manner that 
no current is led through LPG containing parts. GSO STANDARD                                                                     GSO  /    
 
 30 
7.11.4. Electrical cables shall be adequate ly protected against damage.  The 
electrical connections inside the bo ot and passengers compartment shall 
comply with insulation class IP 40 according to IEC 529.  All other electrical connections shall comply w ith insulation class IP 54 according to 
IEC 529. 
 7.11.5. Vehicles with more than one fuel syst em shall have a fuel selection system 
to ensure that no more than one fuel is  supplied to the engine at any time.  
A short overlap time to allow switching-over is allowed. 
 7.11.6. Notwithstanding the provisions of paragraph 7.11.5. in the case of pilot 
operated dual fuel engines, it is perm itted to supply more than one fuel. 
 
7.11.7. The electrical connections and com ponents in the gas-tight housing shall 
be constructed such that no sparks are generated. 
 7.12. Pressure relief device 
 
7.12.1. The pressure relief device shall be fitt ed to the fuel container(s) in such a 
manner that it can discharge into the gas tight housing, when its presence is 
prescribed, if that gas tight hous ing fulfils the requirements of 
paragraph 7.6.5. 
   
 GSO STANDARD                                                                     GSO  /    
 
 31Annex 1  
 
ESSENTIAL CHARACTERISTICS OF THE VEHICLE, ENGINE 
AND LPG-RELATED EQUIPMENT 
 
 0. DESCRIPTION OF THE VEHICLE(S)   0.1. Make:........................................................ .......................................................   0.2. Type(s) ..................................................... .......................................................   0.3.  Name and address of the manufacturer.... .......................................................   1. DESCRIPTION OF THE ENGINE(S) 
 1.1. Manufacturer ............................................ .......................................................   1.1.1. Manufacturer's engine code(s) (as ma rked on the engine, or other means 
of identification)....................................... .......................................................  
 1.2. Internal combustion engine  (1.2.1.-1.2.4.4. not used)  1.2.4.5. Description of the LPG fuelling equipment: 
 
1.2.4.5.1. System description: 
 
1.2.4.5.1.1. Make(s): ................................................... .......................................................  
 1.2.4.5.1.2. Type(s): .................................................... ...................................................... . 
 1.2.4.5.1.3. Drawings/flow charts of the in stallation in the vehicle(s): ..............................  
 1.2.4.5.2. Vaporizer/pressure regulator(s):  1.2.4.5.2.1. Make(s): ................................................... .......................................................  
 1.2.4.5.2.2. Type(s): .................................................... ...................................................... . 
 1.2.4.5.2.3. Certification number: ............................... .......................................................   1.2.4.5.2.4. (not used)  1.2.4.5.2.5. Drawings: ................................................. .......................................................  GSO STANDARD                                                                     GSO  /    
 
 32 
1.2.4.5.2.6. Number of main adjustment points .......... .......................................................   1.2.4.5.2.7. Description of principle of adjustme nt through main adjustment points:........  
 ..........................................................................................................................   1.2.4.5.2.8. Number of idle adjustment points:...................................................................   1.2.4.5.2.9. Description of principles  of adjustment through idle adjustment points: ........  
 ..........................................................................................................................   1.2.4.5.2.10. Other adjustment possibilities: if so  and which (description and drawings): 
 
1.2.4.5.2.11. Operating pressure(s): 2
/ .......................... ................................................. kPa 
 
1.2.4.5.3. Mixing piece: yes/no 1 / 
 1.2.4.5.3.1. Number:.................................................... .......................................................  
 
1.2.4.5.3.2. Make(s): ................................................... .......................................................  
 1.2.4.5.3.3. Type(s): .................................................... ...................................................... . 
 1.2.4.5.3.4. Drawings: ................................................. .......................................................   1.2.4.5.3.5. Place of installation (i nclude drawing(s)): .......................................................  
 1.2.4.5.3.6. Adjustment possibilities:.......................... .......................................................   1.2.4.5.3.7. Operating pressure(s): 2
/ .......................... ................................................. kPa 
 
1.2.4.5.4. Gas dosage unit: yes/no 1 / 
 1.2.4.5.4.1. Number:.................................................... .......................................................  
 
1.2.4.5.4.2. Make(s): ................................................... .......................................................  
 1.2.4.5.4.3. Type(s): .................................................... ...................................................... . 
 1.2.4.5.4.4. Drawings: ................................................. .......................................................   1.2.4.5.4.5. Place of installation (i nclude drawing(s)): .......................................................  
 1.2.4.5.4.6. Adjustment possibilities (description)  GSO STANDARD                                                                     GSO  /    
 
 331.2.4.5.4.7 Operating pressure(s): 2 / .......................... ................................................. kPa 
 
1.2.4.5.5. Gas injection device (s) or Injector(s): yes/no 1 / 
 1.2.4.5.5.1. Make(s): ................................................... .......................................................  
 
1.2.4.5.5.2. Type(s): .................................................... ...................................................... . 
 1.2.4.5.5.3. (not used) 
 
1.2.4.5.5.4. Operating pressure(s): 2
/ .......................... ................................................. kPa 
 
1.2.4.5.5.5. Drawings of installation: .......................... ................................................. kPa 
 
1.2.4.5.6. Electronic Control Unit LPG-fuelling:  1.2.4.5.6.1. Make(s): ................................................... .......................................................  
 1.2.4.5.6.2. Type(s): .................................................... ...................................................... . 
 1.2.4.5.6.3. Place of installation .................................. .......................................................   1.2.4.5.6.4. Adjustment possibilities:.......................... .......................................................   
1.2.4.5.7. LPG container:  
1.2.4.5.7.1. Make(s): ................................................... .......................................................  
 
1.2.4.5.7.2. Type(s) (include drawings):..................... .......................................................   1.2.4.5.7.3 Number of containers:.............................. .......................................................   1.2.4.5.7.4. Capacity: .................................................. ............................................... litres  1.2.4.5.7.5. LPG fuel pump in container: yes/no 1
/ 
 
1.2.4.5.7.6. (not used) 
 
1.2.4.5.7.7. Drawings of the installa tion of the container:..................................................  
 1.2.4.5.8. LPG container accessories 
 
1.2.4.5.8.1. 80 % stop valve:
 
 
1.2.4.5.8.1.1. Make(s): ................................................... ..................................................... ..  
 GSO STANDARD                                                                     GSO  /    
 
 341.2.4.5.8.1.2. Type(s):.................................................... .................................................... ...  
 
1.2.4.5.8.1.3. Operating principle: float/other 1 / (include description or drawings) .............  
 ..........................................................................................................................  
 
1.2.4.5.8.2. Level indicator:  
 
1.2.4.5.8.2.1. Make(s): ................................................... ..................................................... ..  
 
1.2.4.5.8.2.2. Type(s):.................................................... .................................................... ...  
 1.2.4.5.8.2.3. Operating principle: float/other 1
/ (include description or 
drawings).................................................. .......................................................  
 
1.2.4.5.8.3. Pressure relief valve (discharge valve):  
 
1.2.4.5.8.3.1. Make(s): ................................................... ..................................................... ..  
 
1.2.4.5.8.3.2. Type(s):.................................................... .................................................... ...  
 1.2.4.5.8.3.3. Flow rate in standard conditions .....................................................................  
 
1.2.4.5.8.4. Pressure relief device
 
 
1.2.4.5.8.4.1. Make(s) ........................................................................................................ ...  
 
1.2.4.5.8.4.2. Type(s) ........................................................................................................ ....  
 
1.2.4.5.8.4.3. Description and drawings ...............................................................................   1.2.4.5.8.4.4. Operating temperature ....................................................................................   1.2.4.5.8.4.5. Material ....................................................................................................... ....  
 1.2.4.5.8.4.6. Flow rate in standard condition .......................................................................   
1.2.4.5.8.5. Remotely controlled service valve with excess flow valve:
 
 
1.2.4.5.8.5.1. Make(s): ................................................... ..................................................... ..  
 
1.2.4.5.8.5.2. Type(s):.................................................... .................................................... ...  
 1.2.4.5.8.6. Multivalve:
 yes/no 1 / 
 
1.2.4.5.8.6.1. Make(s): ................................................... ..................................................... ..  
 GSO STANDARD                                                                     GSO  /    
 
 351.2.4.5.8.6.2. Type(s):.................................................... .................................................... ...  
 
1.2.4.5.8.6.3. Multivalve description (include drawings) ......................................................   1.2.4.5.8.7. Gas-tight housing:
 
 
1.2.4.5.8.7.1. Make(s): ................................................... ..................................................... ..  
 
1.2.4.5.8.7.2. Type(s):.................................................... .................................................... ...  
 1.2.4.5.8.8. Power supply bushing (fuel pump/actuators):
 
 
1.2.4.5.8.8.1. Make(s): ................................................... ..................................................... ..  
 
1.2.4.5.8.8.2. Type(s):.................................................... .................................................... ...  
 1.2.4.5.8.8.3. Drawings:................................................. ...................................................... . 
 1.2.4.5.9. Fuel pump (LPG): yes/no 1
/ 
 
1.2.4.5.9.1. Make(s): ................................................... .......................................................  
 
1.2.4.5.9.2. Type(s):.................................................... ...................................................... . 
 1.2.4.5.9.3. Pump mounted in LP G container: yes/no 1
/ 
 
1.2.4.5.9.4. Operating pressure(s): 2 /.......................... ................................................. kPa 
 
1.2.4.5.10. Shut-off valve/Non-return valve/ Gas tube pressure relief valve: 
yes/no 1 / 
 1.2.4.5.10.1. Make(s): ................................................... ...................................................... . 
 
1.2.4.5.10.2. Type(s):.................................................... ..................................................... ..  
 1.2.4.5.10.3. Description and drawings: ....................... .......................................................  
 
1.2.4.5.10.4. Operating pressure(s): 2
/.......................... ................................................. kPa 
 
1.2.4.5.11. Remote filling unit: 1 / 
 1.2.4.5.11.1. Make(s): ................................................... ...................................................... . 
 
1.2.4.5.11.2. Type(s):.................................................... ..................................................... ..  
 1.2.4.5.11.3. Description and drawings: ....................... .......................................................  GSO STANDARD                                                                     GSO  /    
 
 36 
1.2.4.5.12. Flexible fuel hose(s)/pipes:  1.2.4.5.12.1. Make(s): ................................................... ...................................................... . 
 1.2.4.5.12.2. Type(s):.................................................... ..................................................... ..  
 1.2.4.5.12.3. Description :............................................. .......................................................  
 1.2.4.5.12.4. Operating pressure(s): 2
/.......................... ................................................. kPa 
 
1.2.4.5.13. Pressure and Temper ature sensor(s): 1 /  
 1.2.4.5.13.1. Make(s): ................................................... ...................................................... . 
 
1.2.4.5.13.2. Type(s):.................................................... ..................................................... ..  
 1.2.4.5.13.3. Description :............................................. .......................................................  
 1.2.4.5.13.4. Operating pressure(s): 2
/.......................... ................................................. kPa 
 
1.2.4.5.14. LPG filter unit(s): 1 /  
 1.2.4.5.14.1. Make(s): ................................................... ...................................................... . 
 
1.2.4.5.14.2. Type(s):.................................................... ..................................................... ..  
 1.2.4.5.14.3. Description :............................................. .......................................................  
 1.2.4.5.14.4. Operating pressure(s): 2
/.......................... ................................................. kPa 
 
1.2.4.5.15. Service coupling(s) (mono-fuel vehi cles without limp-home system): 1 /  
 1.2.4.5.15.1. Make(s): ................................................... ...................................................... . 
 
1.2.4.5.15.2. Type(s):.................................................... ..................................................... ..  
 1.2.4.5.15.3. Description and drawings of installation:  
 
1.2.4.5.16. Connection to LPG system for heating system:  yes/no 1
/  
 
1.2.4.5.16.1. Make(s): ................................................... ...................................................... . 
 
1.2.4.5.16.2. Type(s):.................................................... ..................................................... ..  
 1.2.4.5.16.3. Description and drawings of installation:  GSO STANDARD                                                                     GSO  /    
 
 37 
1.2.4.5.17. Fuel rail: 1 /  
 
1.2.4.5.17.1. Make(s): ................................................... ...................................................... . 
 
1.2.4.5.17.2. Type(s):.................................................... ..................................................... ..  
 1.2.4.5.17.3. Description and drawings of installation:  
 
1.2.4.5.17.4. Operating pressure(s): 2
/.......................... ................................................. kPa 
 
1.2.4.5.18. Further documentation: 
 
1.2.4.5.18.1. Description of the LPG-equipment a nd the physical safeguarding of the 
catalyst at switch-over from petrol to LPG or back 
 
1.2.4.5.18.2. System lay-out (electrical connectio ns, vacuum connections compensation 
hoses, etc.) 
 
1.2.4.5.18.3. Drawing of the symbol: ...................................................................................   1.2.4.5.18.4. Adjustment data: ..............................................................................................   
1.2.4.5.18.5. Certificate of the vehicle on petrol, if already granted: ...................................  
 1.2.5. Cooling system: (liquid/air) 1
/ 
 
1.2.5.1. System description/drawings w ith regard to the LPG equipment 
 
  ___________________  1
/ Strike out what does not apply. 
2/ Specify the tolerance. 
3/ This value must be rounded off to the nearest tenth of a millimetre. 
4/ This value must be calculated with Π = 3.1416 and rounded off, to the nearest cm3. 
 
 GSO STANDARD                                                                     GSO  /    
 
 38Annex 3  
 
PROVISIONS REGARDING THE APPROVAL OF LPG CONTAINER ACCESSORIES 
 
1 80 per cent stop valve  1.1. Definition:  see paragraph 3.5.1. of this Regulation. 
 
1.2. Component classification (according to Figure 1, para. 2.): Class 3.  1.3. Classification pressure: 3,000 kPa.  1.4. Design temperatures:   
-20 °C to 65 °C 
For temperatures exceeding the above-men tioned values, special tests conditions 
are applicable. 
 1.5. General design rules:  
Paragraph 5.15.1., Provisions regard ing 80 per cent stop valve. 
Paragraph 5.15.2., Provisions regard ing the electrical insulation. 
Paragraph 5.15.3.1., Provisions on valves  activated by electrical power. 
 1.6. Applicable test procedures:  
Over pressure test Annex 15, para. 4 
 External leakage Annex 15, para. 5 
 High temperature Annex 15, para. 6 
 Low temperature Annex 15, para. 7  Seat leakage Annex 15, para. 8  Endurance Annex 15, para. 9  Operational test Annex 15, para. 10  LPG compatibility Annex 15, para. 11 **
/ 
Corrosion resistance Annex 15, para. 12 * / 
 Resistance to dry heat Annex 15, para. 13 ** / 
 Ozone ageing Annex 15, para. 14 ** / 
 Creep  Annex 15, para. 15 ** / 
 Temperature cycle Annex 15, para. 16 ** / 
 
2. Level indicator 
 
2.1. Definition:  see paragraph 3.5.2. of this Regulation.  2.2. Component classification (according to Figure 1, para. 2.): Class 1. 
 GSO STANDARD                                                                     GSO  /    
 
 
 392.3. Classification pressure: 3,000 kPa. 
 2.4. Design temperatures:   
-20 °C to 65 °C For temperatures exceeding the above-men tioned values, special tests conditions 
are applicable. 
 2.5. General design rules:  
Paragraph 5.15.11., Provisions rega rding the level indicator. 
 Paragraph 5.15.2., Provisions rega rding the electrical insulation. 
 
2.6. Applicable test procedures:   Over pressure test    Annex 15, para. 4  External leakage    Annex 15, para. 5  High temperature    Annex 15, para. 6  Low temperature    Annex 15, para. 7  LPG compatibility   Annex 15, para. 11 **
/ 
 Corrosion resistance   Annex 15, para. 12 * / 
 Resistance to dry heat   Annex 15, para. 13 ** / 
 Ozone ageing    Annex 15, para. 14 ** / 
 Creep     Annex 15, para. 15 ** / 
 Temperature cycle   Annex 15, para. 16 ** / 
 
3. Pressure relief valve (discharge valve) 
 
3.1. Definition: see paragraph 3.5.3. of this Regulation.  3.2. Component classification (according to Figure 1, para. 2.): Class 3. 
 
3.3. Classification pressure: 3,000 kPa.  3.4. Design temperatures:   
-20 °C to 65 °C For temperatures exceeding the above-men tioned values, special tests conditions 
are applicable. 
 
3.5. General design rules:  
Paragraph 5.15.8., Provisions regarding the pr essure relief valve (discharge valve) 
 3.6. Applicable test procedures:  GSO STANDARD                                                                     GSO  /    
 
 40 Over pressure test Annex 15, para. 4 
 External leakage Annex 15, para. 5  High temperature Annex 15, para. 6  Low temperature Annex 15, para. 7  Seat leakage Annex 15, para. 8  Endurance Annex 15, para. 9 
(with 200 operation cycles) 
Operational test Annex 15, para. 10 LPG compatibility Annex 15, para. 11 **
/ 
Corrosion resistance Annex 15, para. 12 * / 
Resistance to dry heat Annex 15, para. 13 ** / 
Ozone ageing Annex 15, para. 14 ** / 
Creep  Annex 15, para. 15 ** / 
Temperature cycle Annex 15, para. 16 ** / 
 
4. Remotely controlled service valve with excess flow valve 
 
4.1. Definition: see paragraph 3.5.4. of this Regulation.  4.2. Component classification (according to Figure 1, para. 2.): Class 3. 
 
4.3. Classification pressure: 3,000 kPa.  4.4. Design temperatures:   
-20 °C to 65 °C 
For temperatures exceeding the above-men tioned values, special tests conditions 
are applicable. 
 
4.5. General design rules:  
Paragraph 5.15.2., Provisions regard ing the electrical insulation.  
Paragraph 5.15.3.1., Provisions on valves ac tivated by an electrical/external 
power. Paragraph 5.15.13., Provisions regarding the remotely controlled service valve 
with excess flow valve. 
 4.6. Applicable test procedures:   Over pressure test Annex 15, para. 4  External leakage Annex 15, para. 5 
 High temperature Annex 15, para. 6 
 Low temperature Annex 15, para. 7  Seat leakage Annex 15, para. 8  Endurance Annex 15, para. 9  Operational test Annex 15, para. 10 GSO STANDARD                                                                     GSO  /    
 
 
 41 LPG compatibility Annex 15, para. 11 ** / 
 Corrosion resistance Annex 15, para. 12 * / 
 Resistance to dry heat Annex 15, para. 13 ** / 
 Ozone ageing Annex 15, para. 14 ** / 
 Creep  Annex 15, para. 15 ** / 
Temperature cycle Annex 15, para. 16 ** / 
 5. Power supply bushing 
 
5.1. Definition: see paragraph 3.5.8. of this Regulation.  5.2. Component classification (according to Figure 1, para. 2.): Class 1. 
 
5.3. Classification pressure: 3,000 kPa.  5.4. Design temperatures:   
-20 °C to 65 °C For temperatures exceeding the above-men tioned values, special tests conditions 
are applicable. 
 
5.5. General design rules:  
Paragraph 5.15.2., Provisions regard ing the electrical insulation. 
Paragraph 5.15.2.3., Provisions rega rding the power supply bushing. 
 5.6. Applicable test procedures:  
Over pressure test Annex 15, para. 4 External leakage Annex 15, para. 5 High temperature Annex 15, para. 6 Low temperature Annex 15, para. 7 LPG compatibility Annex 15, para. 11 **
/ 
Corrosion resistance Annex 15, para. 12 * / 
Resistance to dry heat Annex 15, para. 13 ** / 
Ozone ageing Annex 15, para. 14 ** / 
Creep  Annex 15, para. 15 ** / 
Temperature cycle Annex 15, para. 16 ** / 
 
6. Gas-tight housing 
 
6.1. Definition: See paragraph 3.5.7. of this Regulation.  6.2. Component classification (accor ding to Figure 1, para. 2.): 
 
Not applicable. GSO STANDARD                                                                     GSO  /    
 
 42 
6.3. Classification pressure: Not applicable.  6.4. Design temperatures:   
-20 °C to 65 °C For temperatures exceeding the above-men tioned values, special tests conditions 
are applicable. 
 6.5. General design rules:  
Paragraph 5.15.12., Provisions rega rding the gas-tight housing. 
 
6.6. Applicable test procedures:   Over pressure test Annex 15, para. 4 (at 50 kPa)  External leakage Annex 15, para. 5 (at 10 kPa)  High temperature Annex 15, para. 6  Low temperature Annex 15, para. 7  7. Provisions regarding the approval of the pressure relief device (fuse) 
 7.1. Definition:  see paragraph 3.5.3.1. of this Regulation.  7.2. Component classification (according to  Figure 1, paragraph 2.): Class 3. 
 
7.3. Classification pressure:  3,000 kPa. 
 
7.4. Design temperature:  
The fuse has to be designed to open at a temperature of 120 ± 10 °C 
 7.5. General design rules   Paragraph 5.15.2., Provisions rega rding the electrical insulation 
Paragraph 5.15.3.1., Provisions on valves  activated by electrical power 
Paragraph 5.15.7., Provisions regarding th e gas tube pressure relief valve 
 
7.6. Test procedures to be applied: 
 
Overpressure test Annex 15, para. 4 External leakage Annex 15, para. 5 High temperature Annex 15, para. 6 Low temperature Annex 15, para. 7 Seat (if any) leakage  Annex 15, para. 8 LPG compatibility Annex 15, para. 11  **
/ GSO STANDARD                                                                     GSO  /    
 
 
 43Corrosion resistance Annex 15, para. 12  * / 
Resistance to dry heat Annex 15, para. 13  ** / 
Ozone ageing Annex 15, para. 14  ** / 
Creep  Annex 15, para. 15  ** / 
Temperature cycles Annex 15, para. 16  ** / 
  7.7. Pressure relief  device (fuse) requirements 
 
Pressure relief device (fuse) specified by the manufacturer shall be shown to be 
compatible with the service conditions by means of the following tests: 
 
 a)  One specimen shall be held at a co ntrolled temperature of not less than 
90 °C and a pressure not less than te st pressure (3,000 kPa) for 24 hours.  
At the end of this test there shall be  no leakage or visibl e sign of extrusion 
of any fusible metal used in the design. 
 
 b)  One specimen shall be fatigue test ed at a pressure cycling rate not to 
exceed 4 cycles per minute as follows: 
 
i) held at 82 °C while pressu red for 10,000 cycles between 300 and 
3,000 kPa; 
 
ii) held at -20 °C while pressured for 10,000 cycles between 300 and 
3,000 kPa. 
   
At the end of this test there shall be no l eakage, or any visible sign of extrusion of 
any fusible metal used in the design. 
 
c)  Exposed brass pressure retaining co mponents of pressure relief device shall 
withstand, without stress corrosion cracking, a mercurous nitrate test as 
described in ASTM B154 ***
/.  The pressure relief device shall be 
immersed for 30 minutes in an a queous mercurous nitrate solution 
containing 10 g of mercurous nitrate and 10 ml of nitric acid per litre of 
solution. Following the imme rsion, the pressure relief  device shall be leak 
tested by applying an aerostatic pr essure of 3,000 kPa for one minute 
during which time the component shall be checked for external leakage. 
Any leakage shall not exceed 200 cm3/h. 
 
d)  Exposed stainless steel pressure re taining components of pressure relief 
device shall be made of an alloy type  resistant to chloride induced stress 
corrosion cracking. 
 
 
_________________ 
 *
/ Only for metallic parts. GSO STANDARD                                                                     GSO  /    
 
 44 
**/ Only for non-metallic parts. 
 
***/ This procedure, or other equi valent, is allowed until an in ternational standard will be 
available.  GSO STANDARD                                                                     GSO  /    
 
 
 45Annex 4  
 
PROVISIONS REGARDING THE APPR OVAL OF THE FUEL PUMP 
 
1 Definition:  see paragr aph 3.5.5. of this Regulation. 
2. Component classification (according to Figure 1, para. 2.): Class 1. 
3. Classification pressure: 3,000 kPa. 
4. Design temperatures:  
-20 °C to 65 °C, when the fuel pump is mounted inside the container. 
-20 °C to 120 °C, when the fuel pump is mounted outside the container. 
For temperatures exceeding the above-men tioned values, special tests conditions 
are applicable. 
5. General design rules: 
Paragraph 5.15.2., Provisions regard ing the electrical insulation. 
Paragraph 5.15.2.1., Provisions rega rding the insulation class. 
Paragraph 5.15.3.2., Provisions when the power is switched off. 
Paragraph 5.15.6.1., Provisions to prevent pressure build-up. 
6. Applicable test procedures: 
6.1. Fuel pump mounted inside the container: 
LPG compatibility Annex 15, para. 11 ** / 
6.2. Fuel pump mounted outside the container: 
Over pressure test Annex 15, para. 4 
 External leakage Annex 15, para. 5 
 High temperature Annex 15, para. 6  Low temperature Annex 15, para. 7  LPG compatibility Annex 15, para. 11 **
/ 
Corrosion resistance Annex 15, para. 12 * / 
 Resistance to dry heat Annex 15, para. 13 ** / 
 Ozone ageing Annex 15, para. 14 ** / 
 Creep  Annex 15, para. 15 ** / 
 Temperature cycle Annex 15, para. 16 ** / 
 
_________________ 
*/ Only for metallic parts. 
 
**/ Only for non-metallic parts. 
 GSO STANDARD                                                                     GSO  /    
 
 
 46Annex 5  
 
PROVISIONS REGARDING THE APPRO VAL OF THE LPG FILTER UNIT 
 
1. Definition:  see paragr aph 3.14. of this Regulation. 
2. Component classification (according to Figure 1, para. 2.): 
 Filter units can be Class 1, 2 or 2A. 3. Classification pressure:  Components of Class 1: 3,000 kPa. 
 Components of Class 2:    450 kPa.  Components of Class 2A:    120 kPa. 
4. Design temperatures: 
-20 °C to 120 °C 
For temperatures exceeding the above-mentioned values, special tests conditions 
are applicable. 
5. General design rules: (not used) 
6. Applicable test procedures: 6.1. For parts of Class 1: 
Over pressure test Annex 15, para. 4 
 External leakage Annex 15, para. 5 
 High temperature Annex 15, para. 6  Low temperature Annex 15, para. 7  LPG compatibility Annex 15, para. 11 **
/ 
Corrosion resistance Annex 15, para. 12 * / 
 Resistance to dry heat Annex 15, para. 13 ** / 
 Ozone ageing Annex 15, para. 14 ** / 
 Creep  Annex 15, para. 15 ** / 
 Temperature cycle Annex 15, para. 16 ** / 
6.2. For parts of Class 2 and/or 2A: 
Over pressure test Annex 15, para. 4 
 External leakage Annex 15, para. 5 
 High temperature Annex 15, para. 6  Low temperature Annex 15, para. 7  LPG compatibility Annex 15, para. 11 **
/ 
Corrosion resistance Annex 15, para. 12 * / 
__________________ 
*/ Only for metallic parts. 
 
**/ Only for non-metallic parts. 
 GSO STANDARD                                                                     GSO  /    
 
 
 47Annex 6  
 
PROVISIONS REGARDING THE APPROVAL  OF THE PRESSURE REGULATOR 
AND THE VAPORIZER 
 
1. Definition:  
Vaporizer: see paragraph 3.6. of this Regulation. Pressure regulator: see para graph 3.7. of this Regulation. 
 2. Component classification (according to Figure 1, para. 2.):  
Class 1: for the part which is in contact  with the pressure of the containers. 
Class 2: for the part which is in contact  with the regulated pressure and with a 
maximum regulated pressure during operation of 450 kPa. 
Class 2A: for the part which is in contac t with the regulated pressure and with a 
maximum regulated pressure during operation of 120 kPa.  
 3. Classification pressure:   Parts of Class 1: 3,000 kPa.  Parts of Class 2:    450 kPa.  Parts of Class 2A:    120 kPa.  4. Design temperatures:   
-20 °C to 120 °C For temperatures exceeding the above-men tioned values, special tests conditions 
are applicable. 
 5. General design rules:  
Paragraph 5.15.2., Provisions regard ing the electrical insulation. 
Paragraph 5.15.3.1., Provisions on valves  activated by external power. 
Paragraph 5.15.4., Heat exchange medium  (compatibility and pressure 
requirements). Paragraph 5.15.5., Overpressure bypass security. 
 Paragraph 5.15.6.2., Gas flow prevention.  GSO STANDARD                                                                     GSO  /    
 
 
 486. Applicable test procedures: 
 6.1. For parts of Class 1:  
Over pressure test Annex 15, para. 4 
 External leakage Annex 15, para. 5  High temperature Annex 15, para. 6  Low temperature Annex 15, para. 7 
Seat leakage Annex 15, para. 8 
 Endurance Annex 15, para. 9  LPG compatibility Annex 15, para. 11 **
/ 
Corrosion resistance Annex 15, para. 12 * / 
 Resistance to dry heat Annex 15, para. 13 ** / 
 Ozone ageing Annex 15, para. 14 ** / 
 Creep  Annex 15, para. 15 ** / 
 Temperature cycle Annex 15, para. 16 ** / 
 
6.2. For parts of Class 2 and/or 2A: 
 
Over pressure test Annex 15, para. 4 
 External leakage Annex 15, para. 5 
 High temperature Annex 15, para. 6 
 Low temperature Annex 15, para. 7 
 LPG compatibility Annex 15, para. 11 ** / 
Corrosion resistance Annex 15, para. 12 * / 
 
Remarks: 
 
The shut-off valve can be integrated in the vapor izer, regulator, in this case Annex 7 is also 
applicable.  
The parts of the pressure regula tor/vaporizer (Class 1,  2 or 2A) shall be leakproof with the 
outlet(s) of that part closed off. 
 For the overpressure test all the outlets includ ing those of the coolan t compartment shall be 
closed off.  __________________ 
 *
/ Only for metallic parts. 
 
**/ Only for non-metallic parts. 
 GSO STANDARD                                                                     GSO  /    
 
 
 49Annex 7  
 
PROVISIONS REGARDING THE APPRO VAL OF THE SHUT-OFF VALVE, 
THE NON-RETURN VALVE, THE GAS-TUBE PRESSURE RELIEF VALVE 
AND THE SERVICE COUPLING 
 
1. Provisions regarding the a pproval of the shut-off valve 
 1.1. Definition:  see paragraph 3.8. of this Regulation.  1.2. Component classification (according to Figure 1, para. 2.): Class 3.  1.3. Classification pressure: 3,000 kPa.  
1.4. Design temperatures:   
-20 °C to 120 °C For temperatures exceeding the above-men tioned values, special tests conditions 
are applicable. 
 1.5. General design rules:  
Paragraph 5.15.2., Provisions regard ing the electrical insulation. 
Paragraph 5.15.3.1., Provisions on valves  activated by electrical power. 
 1.6. Applicable test procedures:  
Over pressure test Annex 15, para. 4 
 External leakage Annex 15, para. 5  High temperature Annex 15, para. 6  Low temperature Annex 15, para. 7 
Seat leakage Annex 15, para. 8 
 Endurance Annex 15, para. 9  LPG compatibility Annex 15, para. 11 **
/ 
Corrosion resistance Annex 15, para. 12 * / 
 Resistance to dry heat Annex 15, para. 13 **  
 Ozone ageing Annex 15, para. 14 ** / 
 Creep  Annex 15, para. 15 ** / 
 Temperature cycle Annex 15, para. 16 ** / 
 
2. Provisions regarding the appr oval of the non-return valve 
 
2.1. Definition:  see paragraph 3.5.9. of this Regulation.  2.2. Component classification (according to Figure 1, para. 2.): Class 1. 
 GSO STANDARD                                                                     GSO  /    
 
 
 502.3. Classification pressure: 3,000 kPa. 
 2.4. Design temperatures:   
-20 °C to 120 °C For temperatures exceeding the above-men tioned values, special tests conditions 
are applicable. 
 2.5. General design rules:  
Paragraph 5.15.2., Provisions regard ing the electrical insulation. 
Paragraph 5.15.3.1., Provisions on valves  activated by electrical power. 
 
2.6. Applicable test procedures:  
Over pressure test Annex 15, para. 4 
 External leakage Annex 15, para. 5  High temperature Annex 15, para. 6  Low temperature Annex 15, para. 7 
Seat leakage Annex 15, para. 8 
 Endurance Annex 15, para. 9  LPG compatibility Annex 15, para. 11 **
/ 
Corrosion resistance Annex 15, para. 12 * / 
 Resistance to dry heat Annex 15, para. 13 ** / 
 Ozone ageing Annex 15, para. 14 ** / 
 Creep  Annex 15, para. 15 ** / 
 Temperature cycle Annex 15, para. 16 ** / 
 
3. Provisions regarding the approval of the gas-tube relief valve 
 
3.1. Definition:  see paragraph 3.9. of this Regulation.  3.2. Component classification (according to Figure 1, para. 2.): Class 3. 
 
3.3. Classification pressure: 3,000 kPa.  3.4. Design temperatures:   
-20 °C to 120 °C For temperatures exceeding the above-men tioned values, special tests conditions 
are applicable. 
 
3.5. General design rules:  
Paragraph 5.15.2., Provisions regard ing the electrical insulation. 
Paragraph 5.15.3.1., Provisions on valves  activated by electrical power. GSO STANDARD                                                                     GSO  /    
 
 
 51Paragraph 5.15.7., Provisions regarding the gas-tube pressure  relief valve. 
  
3.6. Applicable test procedures:  
Over pressure test Annex 15, para. 4 
 External leakage Annex 15, para. 5  High temperature Annex 15, para. 6  Low temperature Annex 15, para. 7 
Seat leakage Annex 15, para. 8 
 Endurance Annex 15, para. 9 
(with 200 operation cycles) 
 LPG compatibility Annex 15, para. 11 **
/ 
Corrosion resistance Annex 15, para. 12 * / 
 Resistance to dry heat Annex 15, para. 13 ** / 
 Ozone ageing Annex 15, para. 14 ** / 
 Creep  Annex 15, para. 15 ** / 
 Temperature cycle Annex 15, para. 16 ** / 
 
4. Provisions regarding the appr oval of the service coupling 
 
4.1. Definition:  see paragraph 3.17. of this Regulation.  4.2. Component classification (according to Figure 1, para. 2.): Class 1. 
 
4.3. Classification pressure: 3,000 kPa.  4.4. Design temperatures:   
-20 °C to 120 °C For temperatures exceeding the above-men tioned values, special tests conditions 
are applicable. 
 
4.5. General design rules:  
Paragraph 5.15.2., Provisions regard ing the electrical insulation. 
Paragraph 5.15.3.1., Provisions on valves  activated by electrical power. 
 GSO STANDARD                                                                     GSO  /    
 
 
 524.6. Applicable test procedures: 
 
Over pressure test Annex 15, para. 4 
 External leakage Annex 15, para. 5  High temperature Annex 15, para. 6  Low temperature Annex 15, para. 7 
Seat leakage Annex 15, para. 8 
 Endurance Annex 15, para. 9 
(with 6,000 operation cycles) 
 LPG compatibility Annex 15, para. 11 **
/ 
Corrosion resistance Annex 15, para. 12 * / 
 Resistance to dry heat Annex 15, para. 13 ** / 
 Ozone ageing Annex 15, para. 14 ** / 
 Creep  Annex 15, para. 15 ** / 
 Temperature cycle Annex 15, para. 16 ** / 
 
 
__________________ 
 *
/ Only for metallic parts. 
 
**/ Only for non-metallic parts. 
 GSO STANDARD                                                                     GSO  /    
 
 
 53Annex 8  
 
PROVISIONS REGARDING THE APPROVAL OF FLEXIBLE HOSES WITH 
COUPLINGS 
 
Scope 
 
The purpose of this annex is to determine the provisions regarding the approval 
of flexible hoses for use with LPG, having an inside diameter up to 20 mm. 
 
This annex covers three types of flexible hoses: 
  (i) High pressure rubber hose s (Class 1, e.g. Filling hose) 
(ii) Low pressure rubber hoses (Class 2) (iii) High pressure synt hetic hoses (Class 1) 
 
1.  HIGH PRESSURE RUBBER HOS ES, CLASS 1 CLASSIFICATION, 
FILLING HOSE 
 
1.1.  General specifications  1.1.1.  The hose shall be so designed as to  withstand a maximum operating pressure 
of 3,000 kPa. 
 1.1.2.  The hose shall be so desi gned as to withstand temper atures between -25 °C and 
+80 °C.  For operating temperatures ex ceeding the above- mentioned values, 
the test temperatures must be adapted. 
 1.1.3.  The inside diameter shall be in co mpliance with Table 1 of standard ISO 1307. 
 1.2.  Hose construction  1.2.1.  The hose must embody a smooth-bore tube  and a cover of suitable synthetic 
material, reinforced with one or more interlayer(s). 
 1.2.2.  The reinforcing interlayer(s) has (hav e) to be protected by a cover against 
corrosion. 
 
If for the reinforcing interlayer(s) corrosion-resistant-material is used (i.e. stainless-steel) a cover is not required. 
 1.2.3.  The lining and the cover must be smooth and free from pores, holes and 
strange elements.  An intentionally provided puncture in th e cover shall not be considered as an 
imperfection. 
 GSO STANDARD                                                                     GSO  /    
 
 
 541.2.4.  The cover has to be intentionally pe rforated to avoid the forming of bubbles. 
 
1.2.5.  When the cover is punctured and the interlayer is made of a non-corrosion-
resistant material, the interlayer ha s to be protected against corrosion. 
 1.3.  Specifications and tests for the lining 
 1.3.1.  Tensile strength and elongation  1.3.1.1.  Tensile strength and elongation at break
 according to ISO 37.   Tensile strength 
not less than 10 MPa and elongation at break not less than 250 per cent. 
 
1.3.1.2.  Resistance to n-pentane  according to ISO 1817 with the following conditions: 
(i) medium: n-pentane 
  (ii) temperature: 23 °C  (tolerance acc. to ISO 1817) 
  (iii) immersion period: 72 hours 
 
Requirements:  
  (i) maximum change in volume 20 per cent 
  (ii) maximum change in tensile strength 25 per cent 
  (iii) maximum change in elongation at break 30 per cent 
After storage in air with a temperatur e of 40 °C for a period of 48 hours the 
mass compared to the original value ma y not decrease more than 5 per cent. 
 1.3.1.3.  Resistance to ageing
 according to ISO 188 with the following conditions: 
(i) temperature: 70 °C (test temper ature = maximum operating temperature 
minus 10 °C) 
(ii) exposure period: 168 hours  Requirements: 
  (i) maximum change in tensile strength 25 per cent 
  (ii) maximum change in elongation at break -30 per cen t and +10 per cent 
 
1.4.  Specifications and test-method for the cover  1.4.1.  Tensile strength an d elongation at break
 according to ISO 37. Tensile strength 
not less than 10 MPa and elongation at break not less than 250 per cent. 
 
1.4.1.1.  Resistance to n-hexane  according to ISO 1817 with the following conditions: 
(i) medium: n-hexane 
  (ii) temperature: 23 °C  (tolerance acc. to ISO 1817) 
  (iii) immersion period: 72 hours 
 
Requirements:  
  (i) maximum change in volume 30 per cent 
  (ii) maximum change in tensile strength 35 per cent GSO STANDARD                                                                     GSO  /    
 
 
 55  (iii) maximum change in elongation at break 35 per cent 
 1.4.1.2.  Resistance to ageing according
 to ISO 188 with the following conditions: 
(i) temperature: 70 °C (test temper ature = maximum operating temperature 
minus 10 °C) 
(ii) exposure period:  336 hours 
 
Requirements: 
  (i) maximum change in tensile strength 25 per cent 
  (ii) maximum change in elongation at break -30 per cen t and +10 per cent 
 
1.4.2.  Resistance to ozone  1.4.2.1.  The test has to be performed in  compliance with standard ISO 1431/1. 
 1.4.2.2.  The test-pieces, which have to be stretched to an el ongation of 20 per cent 
shall have to be exposed to air of 40 °C with an ozone-concentration of 50 
parts per hundred million during 120 hours. 
 
1.4.2.3.  No cracking of the test pieces is allowed.  1.5.  Specifications for uncoupled hose  1.5.1.  Gas-tightness (permeability)  1.5.1.1.  A hose at a free length of 1 m has to be connected to a co ntainer filled with 
liquid propane, having a temperature of 23 ± 2 °C. 
 1.5.1.2.  The test has to be carried out in compliance with the method described in 
standard ISO 4080. 
 1.5.1.3.  The leakage through the wall of the hose shall not exceed 95 cm
3 of vapour per 
metre of hose per 24 h. 
 
1.5.2.  Resistance at low temperature 
 1.5.2.1.  The test has to be carried out in compliance with the method described in 
standard ISO 4672:1978 method B. 
 
1.5.2.2.  Test-temperature: -25 ± 3 °C. 
 
1.5.2.3.  No cracking or rupture is allowed.  1.5.3.  (Not used)  
1.5.4.  Bending test GSO STANDARD                                                                     GSO  /    
 
 
 56 
1.5.4.1.  An empty hose, at a length of approx imately 3.5 m must be able to withstand 
3,000 times the hereafter prescribed altern ating-bending-test w ithout breaking.  
After the test the hose must be capable of withstanding the test-pressure as 
mentioned in paragraph 1.5.5.2. 
 1.5.4.2.       
      
Figure 1 (example only)
 
 
Distance between centres  [mm] 
(Figure 1) Hose inside diameter 
[mm] Bending radius 
[mm] 
 
(Figure 1) Vertical 
b Horizontal 
a 
up to 13 102 241 102 
13 to 16 153 356 153 
from 16 to 20 178 419 178 
 
 1.5.4.3.  The testing machine (see Figure 1) shall consist of a steel frame, provided with 
two wooden wheels, with a rim-width of c.a. 130 mm. 
 
The circumference of the wheels must be  grooved for the guidance of the hose.  
The radius of the wheels, measured to the bottom of the groove, must be as 
indicated in paragraph 1.5.4.2. 
 
The longitudinal median planes of both wheels must be in the same vertical 
plane and the distance between the wheel- centres must be in accordance with 
paragraph 1.5.4.2. 
 
Each wheel must be able to rota te freely round its pivot-centre. 
 ab
propulsion mechanismmass
1,2m
 GSO STANDARD                                                                     GSO  /    
 
 
 57A propulsion mechanism pulls the hose over the wheels at a speed of four 
complete motions per minute. 
 
1.5.4.4.  The hose shall be S-shape-like installed over the wheels (see Figure 1).  
The end, that runs over the upper wheel shall be furnished with a sufficient 
mass as to achieve a complete snuggling of the hose against the wheels.  The part that runs over the lower wheel is attached to the propulsion mechanism. 
 
The mechanism must be so adjusted, that  the hose travels a total distance of 
1.2 m in both directions. 
 1.5.5. Hydraulic test pressure  and determination of the minimum burst-pressure 
 
1.5.5.1. The test has to be carried out in compliance with the method described in 
standard ISO 1402. 
 1.5.5.2. The test-pressure of 6,750 kPa shall be  applied during 10 mi nutes, without any 
leakage. 
 1.5.5.3. The burst pressure shall not be less than 10,000 kPa. 
 1.6. Couplings  1.6.1. The couplings shall be made from st eel or brass and the surface must be 
corrosion-resistant. 
 1.6.2. The couplings must be of the crimp-fitting type.  1.6.2.1. The swivel-nut must be provided with U.N.F. thread.  1.6.2.2. The sealing cone of swivel-nut type must  be of the type w ith a half vertical 
angle of 45 °. 
 1.6.2.3. The couplings can be made as swivel- nut type or as qui ck-connector type. 
 1.6.2.4. It shall be impossible to disconnect the quick-connector ty pe without specific 
measures or the use of dedicated tools. 
 1.7. Assembly of hose and couplings  1.7.1. The construction of the couplings must be  such, that it is no t necessary to peel 
the cover unless the reinforcement of th e hose consists of corrosion-resistant 
material. 
 1.7.2. The hose assembly has to be subjected to an impulse test in compliance with GSO STANDARD                                                                     GSO  /    
 
 
 58standard ISO 1436. 
 
1.7.2.1. The test has to be completed with ci rculating oil having a temperature of 
93 °C, and a minimum pressure of 3,000 kPa. 
 1.7.2.2. The hose has to be subjected to 150,000 impulses.  1.7.2.3. After the impulse test th e hose has to withstand the test-pressure as mentioned 
in paragraph 1.5.5.2. 
 1.7.3. Gas-tightness  1.7.3.1. The hose assembly (hose with couplings ) has to withstand during five minutes 
a gas pressure of 3,000 kP a without any leakage. 
 
1.8. Markings  1.8.1. Every hose must bear, at intervals of not greater than 0.5 m, the following 
clearly legible and indelible identifica tion markings consisting of characters, 
figures or symbols. 
 1.8.1.1. The trade name or mark  of the manufacturer. 
 1.8.1.2. The year and month of fabrication.  1.8.1.3. The size and type-marking.  1.8.1.4. The identification marking "L.P.G. Class 1".  1.8.2. Every coupling shall bear the trad e name or mark of the assembling 
manufacturer. 
 2. LOW PRESSURE RUBBER HOSE S, CLASS 2 CLASSIFICATION 
 2.1. General specifications  2.1.1. The hose shall be so designed as to withstand a maximum operating pressure 
of 450 kPa. 
 2.1.2. The hose shall be so desi gned as to withstand temper atures between -25 °C and 
+125 °C.  For operating temperatures exceeding the above- mentioned values, the test temperatures must be adapted. 
 2.2. Hose construction  2.2.1. The hose must embody a smooth-bore tube  and a cover of suitable synthetic GSO STANDARD                                                                     GSO  /    
 
 
 59material, reinforced with one or more interlayer(s). 
 
2.2.2. The reinforcing interlayer(s) has (hav e) to be protected by a cover against 
corrosion. 
 
If for the reinforcing interlayer(s) corrosion-resistant material is used 
(i.e. stainless steel) a cover is not required. 
 2.2.3. The lining and the cover must be smooth and free from pores, holes and 
strange elements. An intentionally provided puncture in th e cover shall not be considered as an 
imperfection. 
 
2.3. Specifications and tests for the lining 
 2.3.1. Tensile strength and elongation  2.3.1.1. Tensile strength and elongation at break  according to ISO 37. Tensile strength 
not less than 10 MPa and elongation at break not less than 250 per cent. 
 2.3.1.2. Resistance to n-pentane according to ISO 1817 with the following conditions:  (i) medium: n-pentane  (ii) temperature: 23 °C (tolerance acc. to ISO 1817) 
 (iii) immersion period: 72 hours   Requirements:   (i) maximum change in volume 20 per cent  (ii) maximum change in tensile strength 25 per cent  (iii) maximum change in elongation at break 30 per cent 
After storage in air with a temperatur e of 40 °C for a period of 48 hours the 
mass compared to the original value ma y not decrease more than 5 per cent. 
 2.3.1.3. Resistance to ageing according to ISO 188 with the following conditions: 
 (i) temperature: 115 °C (test temper ature = maximum operating temperature 
minus 10 °C)  
 (ii) exposure period: 168 hours   Requirements:  (i) maximum change in tensile strength 25 per cent  (ii) maximum change in elongation at break -30 per cen t and +10 per cent 
 2.4. Specifications and test method for the cover  2.4.1.1. Tensile strength and elongation at break  according to ISO 37. Tensile strength 
not less than 10 MPa and elongation at break not less than 250 per cent. 
 GSO STANDARD                                                                     GSO  /    
 
 
 602.4.1.2. Resistance to n-hexane according to  ISO 1817 with the following conditions: 
 (i) medium: n-hexane 
 (ii) temperature: 23 °C (tolerance acc. to ISO 1817) 
 (iii) immersion period: 72 hours   Requirements:   (i) maximum change in volume 30 per cent  (ii) maximum change in tensile strength 35 per cent  (iii) maximum change in elongation at break 35 per cent  2.4.1.3. Resistance to ageing according to ISO 188 with the following conditions: 
 (i) temperature: 115 °C (test temper ature = maximum operating temperature 
minus 10 °C) 
 (ii) exposure period: 336 hours 
  Requirements:  (i) maximum change in tensile strength 25 per cent  (ii) maximum change in elongation at break -30 per cen t and +10 per cent 
 2.4.2. Resistance to ozone  2.4.2.1. The test has to be performed in  compliance with standard ISO 1431/1. 
 2.4.2.2. The test-pieces, which have to be st retched to an elonga tion of 20 per cent 
shall have to be exposed to air of 40 °C with an ozone co ncentration of 50 
parts per hundred million during 120 hours. 
 2.4.2.3. No cracking of the test pieces is allowed.  2.5. Specifications for uncoupled hose  2.5.1. Gas-tightness (permeability)  2.5.1.1. A hose at a free length of 1 m has to be  connected to a co ntainer filled with 
liquid propane, having a temperature of 23 ± 2 °C. 
 2.5.1.2. The test has to be carried out in compliance with the method described in 
standard ISO 4080. 
 2.5.1.3. The leakage through the wall of the hose shall not exceed 95 cm
3 of vapour per 
metre of hose per 24 h. 
 
2.5.2. Resistance at low temperature 
 2.5.2.1. The test has to be carried out in compliance with the method described in 
standard ISO 4672-1978 method B. GSO STANDARD                                                                     GSO  /    
 
 
 61 
2.5.2.2. Test-temperature:  -25 ± 3 °C 
 
2.5.2.3. No cracking or rupture is allowed.  2.5.3. Bending test  2.5.3.1. An empty hose, at a length of approx imately 3.5 m must be able to withstand 
3,000 times the hereafter pres cribed alternating-bending- test without breaking.  
After the test the hose must be capable of withstanding the test pressure as 
mentioned in paragraph 2.5.4.2. 
 2.5.3.2. 
         
Figure 2 (example only)
 
 
Distance between centres [mm] 
(Figure 2) Hose inside diameter 
[mm] Bending radius 
[mm] 
 
(Figure 2) Vertical 
b Horizontal 
a 
up to 13 102 241 102 
13 to 16 153 356 153 
from 16 to 20 178 419 178 
 
2.5.3.3. The testing machine (see Figure 2) shall consist of a steel frame, provided with 
two wooden wheels, with a rim-width of c.a. 130 mm. 
 
The circumference of the wheels must be  grooved for the guidance of the hose.  
The radius of the wheels, measured to the bottom of the groove, must be as 
indicated in paragraph 2.5.3.2. 
 
The longitudinal median planes of both wheels must be in the same vertical 
plane and the distance between the wheel- centres must be in accordance with 
paragraph 2.5.3.2. 
 ab
propulsion mechanismmass
1,2mGSO STANDARD                                                                     GSO  /    
 
 
 62Each wheel must be able to rota te freely round its pivot-centre. 
 
A propulsion mechanism pulls the hose over the wheels at a speed of four 
complete motions per minute. 
 
2.5.3.4. The hose shall be S-shape-like installed over the wheels (see Figure 2).  
The end that runs over th e upper wheel shall be furnished with a sufficient 
mass as to achieve a complete snuggling of the hose against the wheels.  The part that runs over the lower wheel is attached to the propulsion mechanism. 
 
The mechanism must be so adjusted, that  the hose travels a total distance of 
1.2 m in both directions. 
 
2.5.4. Hydraulic test pressure  and determination of the minimum burst-pressure 
 2.5.4.1. The test has to be carried out in compliance with the method described in 
standard ISO 1402. 
 2.5.4.2. The test pressure of 1,015 kPa shall be applied during 10 minutes, without any 
leakage. 
 2.5.4.3. The burst pressure shall not be less than 1,800 kPa. 
 2.6. Couplings  2.6.1. The couplings shall be made from a non-corrosive material.  2.6.2. The coupling burst pressure in mounte d position shall never be less than the 
tube or hose burst pressure. The coupling leakage pressure in mounted  position shall never be less than the 
tube or hose leakage pressure. 
 2.6.3. The couplings must be of the crimp-fitting type.  2.6.4. The couplings can be made as swivel- nut type or as qui ck-connector type. 
 2.6.5. It shall be impossible to disconnect the quick-connector ty pe without specific 
measures or the use of dedicated tools. 
 2.7. Assembly of hose and couplings  2.7.1. The construction of the couplings must be  such, that it is not necessary to peel 
the cover unless the reinforcement of th e hose consists of corrosion-resistant 
material. 
 GSO STANDARD                                                                     GSO  /    
 
 
 632.7.2. The hose assembly has to be subjected to an impulse test in compliance with 
standard ISO 1436. 
 
2.7.2.1. The test has to be completed with ci rculating oil having a temperature of 
93 °C, and a minimum pressure of 1,015 kPa. 
 2.7.2.2. The hose has to be subjected to 150,000 impulses.  2.7.2.3. After the impulse test th e hose has to withstand the test-pressure as mentioned 
in paragraph 2.5.4.2. 
 2.7.3. Gas-tightness  
2.7.3.1. The hose assembly (hose with couplings ) has to withstand during five minutes 
a gas pressure of 1,015 kP a without any leakage. 
 2.8. Markings  2.8.1. Every hose must bear, at intervals of not greater than 0.5 m, the following 
clearly legible and indelible identifica tion markings consisting of characters, 
figures or symbols. 
 2.8.1.1. The trade name or mark  of the manufacturer. 
 2.8.1.2. The year and month of fabrication.  2.8.1.3. The size and type-marking.  2.8.1.4. The identification marking "L.P.G. Class 2".  2.8.2. Every coupling shall bear the trad e name or mark of the assembling 
manufacturer. 
 3. HIGH PRESSURE SYNTHETIC HOS ES, CLASS 1 CLASSIFICATION 
 3.1. General specifications  3.1.1. The purpose of this chapter is to determine the provisions regarding the 
approval of synthetic flexible hoses for use with LPG, having an inside 
diameter up to 10 mm. 
 3.1.2. This chapter covers, in addition to gene ral specifications a nd tests for synthetic 
hoses, also specifications and tests applic able for specific material types or a 
synthetic hose. 
 3.1.3. The hose shall be so designed as to withstand a maximum operating pressure GSO STANDARD                                                                     GSO  /    
 
 
 64of 3,000 kPa. 
 
3.1.4. The hose shall be so desi gned as to withstand temper atures between -25 °C and 
+125 °C.  For operating temperatures exceeding the above-mentioned values, the test temperatures must be adapted. 
 3.1.5. The inside diameter shall be in comp liance with Table 1 of standard ISO 1307. 
 3.2. Hose construction  3.2.1. The synthetic hose must embody a therm oplastic tube and a cover of suitable 
thermoplastic material, oil and weatherp roof, reinforced with one or more 
synthetic interlayer(s).  If for the rein forcing interlayer(s) a corrosion-resistant 
material is used (i.e. stainless- steel) a cover is  not required. 
 
3.2.2. The lining and the cover must be free from pores, holes and strange elements. 
An intentionally provided puncture in th e cover shall not be considered as an 
imperfection. 
 3.3. Specifications and tests for the lining 
 3.3.1. Tensile strength and elongation  3.3.1.1. Tensile strength an d elongation at break
 according to ISO 37. Tensile strength 
not less than 20 MPa and elongation at break not less than 200 per cent. 
 
3.3.1.2. Resistance to n-pentane  according to ISO 1817 with the following conditions: 
 (i) medium: n-pentane 
 (ii) temperature: 23 °C (tolerance acc. to ISO 1817) 
 (iii) immersion period: 72 hours 
  Requirements:   (i) maximum change in volume 20 per cent 
 (ii) maximum change in tensile strength 25 per cent 
 (iii) maximum change in elongation at break 30 per cent 
After storage in air with a temperatur e of 40 °C for a period of 48 hours the 
mass compared to the original value ma y not decrease more than 5 per cent. 
 3.3.1.3. Resistance to ageing
 according to ISO 188 with the following conditions: 
 (i) temperature: 115 °C (test temper ature = maximum operating temperature 
minus 10 °C) 
 (ii) exposure period: 336 hours   Requirements:  (i) maximum change in tensile strength 35 per cent 
 (ii) maximum change in elongation at break -30 per cen t and +10 per cent GSO STANDARD                                                                     GSO  /    
 
 
 65 
3.3.2.  Tensile strength and elongation sp ecific for polyamide 6 material 
 3.3.2.1. Tensile strength and elongation at break
 according to ISO 527-2 with the 
following conditions: 
(i) specimen type: type 1 BA 
(ii) tensile speed: 20 mm/min 
The material has to be conditioned for at  least 21 days at 23 °C and 50 per cent 
relative humidity prior to testing. 
 
Requirements: (i) tensile strength not less than 20 MPa  (ii) elongation at break not less than 50 per cent. 
 3.3.2.2. Resistance to n-pentane
 according to ISO 1817 with the following conditions: 
(i) medium: n-pentane 
(ii) temperature: 23 °C (tolerance according to ISO 1817) 
(iii) immersion period: 72 hours 
 
Requirements: 
(i) maximum change in volume 2 per cent 
(ii) maximum change in te nsile strength 10 per cent 
(iii) maximum change in elongation at break 10 per cent 
After storage in air with a temperatur e of 40 °C for a period of 48 hours the 
mass compared to the original value ma y not decrease more than 5 per cent. 
 
3.3.2.3. Resistance to ageing  according to ISO 188 with the following conditions: 
(i) temperature: 115 °C (test temperature = maximum operating 
temperature minus 10 °C) 
(ii) exposure period: 24 and 336 hours After ageing the specimens have to be conditioned at 23 °C and 50 per cent relative humidity for at least 21 days prior to carrying out the tensile test according to paragraph 3.3.2.1. 
 
Requirements: (i) maximum change in tensile stre ngth 35 per cent after 336 hours ageing 
compared to the tensile strength of the 24 hours aged material 
(ii) maximum change in elongation at break 25 per cent after 336 hours 
ageing compared to the elongation at break of the 24 hours aged material. 
 
3.4. Specifications and test method for the cover  3.4.1.1. Tensile strength and elongation at break
 according to ISO 37.   Tensile strength 
not less than 20 MPa and elongation at break not less than 250 per cent. 
 GSO STANDARD                                                                     GSO  /    
 
 
 663.4.1.2. Resistance to n-hexane  according to ISO 1817 with the following conditions: 
 (i) medium: n-hexane  (ii) temperature: 23 °C (tolerance according to ISO 1817) 
 (iii) immersion period: 72 hours 
  Requirements:   (i) maximum change in volume 30 per cent 
 (ii) maximum change in tensile strength 35 per cent 
 (iii) maximum change in elongation at break 35 per cent  3.4.1.3. Resistance to ageing according
 to ISO 188 with the following conditions: 
 (i) temperature: 115 °C (test temper ature = maximum operating temperature 
minus 10 °C) 
 (i) exposure period: 336 hours   Requirements:  (i) maximum change in tensile strength 25 per cent 
 (ii) maximum change in elongation at break -30 per cen t and +10 per cent 
 
3.4.2. Resistance to ozone  3.4.3.  Specifications and test method for th e cover made of polyamide 6 material 
 3.4.3.1. Tensile strength and elongation at break
 according to ISO 527-2 with the 
following conditions: 
(i) specimen type: type 1 BA 
(ii) tensile speed: 20 mm/min 
 
The material has to be conditioned for at least 21 days at 23 °C and 50 per cent 
relative humidity prior to testing. 
 
Requirements: (i) tensile strength not less than 20 MPa  (ii) elongation at break not less than 100 per cent. 
 3.4.3.2. Resistance to n-hexane
 according to ISO 1817 with the following conditions: 
(i) medium: n-hexane 
(ii) temperature: 23 °C (tolerance according to ISO 1817) 
(iii) immersion period: 72 hours 
 
Requirements: 
(i) maximum change in volume 2 per cent 
(ii) maximum change in tensile strength 10 per cent 
(iii) maximum change in elongation at break 10 per cent  
3.4.3.3. Resistance to ageing
 according to ISO 188 with the following conditions: GSO STANDARD                                                                     GSO  /    
 
 
 67(i) temperature: 115 °C (test temper ature = maximum operating temperature 
minus 10 °C) 
(ii) exposure period: 24 and 336 hours 
After ageing the specimens have to be conditioned for at least 21 days before carrying out the tensile test according to paragraph 3.3.1.1. 
 
Requirements: 
(i) maximum change in tensile strength 20 per cent after 336 hours ageing 
compared to the tensile strength of the 24 hours aged material 
(ii) maximum change in elongation at break 50 per cent after 336 hours 
ageing compared to the elongation at break of the 24 hours aged material.  
 3.4.2.1. The test has to be performed in  compliance with standard ISO 1431/1. 
 
3.4.2.2. The test-pieces, which have to be st retched to an elonga tion of 20 per cent 
shall have to be exposed to air of 40 °C and a relative humidity of 50 per cent 
± 10 per cent with an ozone-concentr ation of 50 parts per hundred million 
during 120 hours. 
 
3.4.2.3. No cracking of the test pieces is allowed.  3.5. Specifications for uncoupled hose  3.5.1. Gas-tightness (permeability)  3.5.1.1. A hose at a free length of 1 m has to be  connected to a co ntainer filled with 
liquid propane, having a temperature of 23 ± 2 °C. 
 3.5.1.2. The test has to be carried out in compliance with the method described in 
standard ISO 4080. 
 3.5.1.3. The leakage through the wall of the hose shall not exceed 95 cm
3 of vapour per 
metre of hose per 24 h. 
 
3.5.2. Resistance at low temperature 
 3.5.2.1. The test has to be carried out in compliance with the method described in 
standard ISO 4672 method B. 
 
3.5.2.2. Test temperature: -25 ± 3 °C. 
 
3.5.2.3. No cracking or rupture is allowed.  3.5.3. Resistance at high temperature  
3.5.3.1. A piece of hose, pressurized at 3,000 kP a, with a minimal length of 0.5 m must GSO STANDARD                                                                     GSO  /    
 
 
 68be put in an oven at a temperature of 125 ± 2 °C during 24 hours. 
 
3.5.3.2. No leakage is allowed.  3.5.3.3. After the test the hose shall withstand the test pressure of 6,750 kPa during 
10 minutes.  No leakage is allowed. 
 3.5.4. Bending test  3.5.4.1. An empty hose, at a length of approx imately 3.5 m must be able to withstand 
3,000 times the hereafter pres cribed alternating-bending- test without breaking.  
After the test the hose must be capable of withstanding the test pressure as 
mentioned in paragraph 3.5.5.2. 
 
          
Figure 3 (example only)
     (a = 102 mm;   b= 241 mm) 
 
 
3.5.4.2. The testing machine (see Figure 3) shall consist of a steel frame, provided with 
two wooden wheels, with a rim-width of approximately 130 mm. 
 
The circumference of the wheels must be  grooved for the guidance of the hose.  
The radius of the wheels, measured to  the bottom of the groove, must be 102 
mm. 
 
The longitudinal median planes of both wheels must be in the same vertical 
plane.  The distance between the wheel -centres must be vertical 241 mm and 
horizontal 102 mm. 
 
Each wheel must be able to rota te freely round its pivot-centre. 
 
A propulsion mechanism pulls the hose over the wheels at a speed of four 
complete motions per minute. 
 
3.5.4.3. The hose shall be S-shape-like installed over the wheels (see Figure 3).  
The end, that runs over the upper wheel, sh all be furnished with a sufficient ab
propulsion mechanismmass
1,2mGSO STANDARD                                                                     GSO  /    
 
 
 69mass as to achieve a complete snuggling of the hose against the wheels.  The 
part that runs over the lower wheel is attached to the propulsion mechanism. 
 
The mechanism must be so adjusted, that  the hose travels a total distance of 
1.2 m in both directions. 
 3.5.5. Hydraulic test pressure  and determination of the minimum burst-pressure 
 3.5.5.1. The test has to be carried out in compliance with the method described in 
standard ISO 1402. 
 3.5.5.2. The test pressure of 6,750 kPa shall be applied during 10 minutes, without any 
leakage. 
 
3.5.5.3. The burst pressure shall not be less than 10,000 kPa. 
 3.6. Couplings  3.6.1. The couplings shall be made from st eel or brass and the surface must be 
corrosion-resistant. 
 3.6.2. The couplings must be of the crim p-fitting type and made up of a hose-
coupling or banjo bolt.  The sealing sha ll be resistant to LPG and comply with 
paragraph 3.3.1.2. 
 3.6.3. The banjo bolt shall comply with DIN 7643.  3.7. Assembly of hose and couplings  3.7.1. The hose assembly has to be subjected to an impulse test in compliance with 
standard ISO 1436. 
 3.7.1.1. The test has to be completed with ci rculating oil having a temperature of 
93 °C, and a minimum pressure of 3,000 kPa. 
 3.7.1.2. The hose has to be subjected to 150,000 impulses.  3.7.1.3. After the impulse-test the hose has to w ithstand the test pressure as mentioned 
in paragraph 3.5.5.2. 
 3.7.2. Gas-tightness  3.7.2.1. The hose assembly (hose with couplings ) has to withstand during five minutes 
a gas pressure of 3,000 kP a without any leakage. 
 3.8. Markings GSO STANDARD                                                                     GSO  /    
 
 
 70 
3.8.1. Every hose must bear, at intervals of not greater than 0.5 m, the following 
clearly legible and indelible identifica tion markings consisting of characters, 
figures or symbols. 
 3.8.1.1. The trade name or mark  of the manufacturer. 
 3.8.1.2. The year and month of fabrication.  3.8.1.3. The size and type-marking.  3.8.1.4. The identification marking "L.P.G. Class 1".  
3.8.2. Every coupling shall bear the trad e name or mark of the assembling 
manufacturer. 
 GSO STANDARD                                                                     GSO  /    
 
 
 71Annex 9  
 
PROVISIONS REGARDING THE APPR OVAL OF THE FILLING UNIT 
 
1. Definition:  see paragr aph 3.16. of this Regulation. 
2. Component classification (according to Figure 1, para. 2.): 
Filling unit:  Class 3 
 Non-return valve:  Class 3 
3. Classification pressure: 3,000 kPa. 4. Design temperatures:  
-20 °C to 65 °C 
For temperatures exceeding the a bove-mentioned values, special tests 
conditions are applicable. 
5. General design rules: 
Paragraph 6.15.2., Provisions regard ing the electrical insulation. 
 Paragraph 6.15.10., Provisions re garding the filling unit. 
6. Applicable test procedures: 
Over pressure test Annex 15, para. 4 
External leakage Annex 15, para. 5 High temperature Annex 15, para. 6 Low temperature Annex 15, para. 7 Seat leakage test Annex 15, para. 8 Endurance Annex 15, para. 9 
(with 6,000 operation cycles) 
LPG compatibility Annex 15, para. 11 **
/ 
Corrosion resistance Annex 15, para. 12 * / 
Resistance to dry heat Annex 15, para. 13  
Ozone ageing  Annex 15, para. 14  
Creep Annex 15, para. 15 ** / 
Temperature cycle Annex 15, para. 16 ** / 
Impact test paragraph 7. of this annex 
 7. Impact test requirements for the Euro filling unit 
 
7.1. General requirements 
  The filling unit shall be subjected to an impact test of 10 J.  
 GSO STANDARD                                                                     GSO  /    
 
 
 727.2. Test procedure 
 
A hardened steel mass of 1 kg shall be dropped from a height of 1 m so as to 
deliver the impact velocity 4.4 m/s.  This shall be achieved by mounting the 
mass in a pendulum. 
 
The filling unit shall be installed horizont ally on a solid object. The impact of 
the mass shall be on the centre of the protruding part of the filling unit. 
 
7.3. Test interpretation 
 
The filling unit shall comply with the external leak test and seat leak test at ambient temperature. 
 7.4. Re-testing  
If the filling unit fails the test, 2 samples of the same component shall be submitted to the impact test.  If both samples pass the test, the first test shall be ignored.  In the event where one or both fail the re-test, the component shall not be approved. 
 
__________________  *
/ Only for metallic parts. 
 
**/ Only for-non metallic parts. 
 Remarks
: 
 - The overpressure test has to be performed on each non-return valve. 
 
- The endurance test shall be carried out with  a nozzle specifically intended for the filling 
unit under test.  6,000 cyles shall be applie d according to the following procedure: 
 
- connect the nozzle to the connector and open the filling unit system; 
-  leave in open situati on for at least 3 seconds; 
- close the filling unit and disconnect the nozzle. GSO STANDARD                                                                     GSO  /    
 
 
 73
 
  
Figure 1
 - Connecting area of the Bayonet filling unit 
  
 
   
 
     
 
 
      
Figure 2
 - Connecting area of the Dish filling unit 
 
 GSO STANDARD                                                                     GSO  /    
 
 
 74 
Figure 3  - Connecting area of the light  vehicle Euro filling unit 
  
 
   
 
 
      
       
Figure 4
: - Connecting area of the ACME filling unit 
 
GSO STANDARD                                                                     GSO  /    
 
 
 75Dimensions in millimetres 
 
Keys: 1  Nozzle sealing surface  
2  Minimum valve travel  3  General tolerance   
Figure 5
: - Connecting area of the hea vy-duty vehicle Euro filling unit 
 GSO STANDARD                                                                     GSO  /    
 
 
 76Annex 10  
 
PROVISIONS REGARDING THE APPR OVAL OF LPG CONTAINERS 
 
The meaning of symbols and terms used in this annex  P
h = hydraulic test pressure in kPa; 
 
Pr = container bursting pressure measur ed in the bursting test, in kPa; 
 R
e = minimum yield stress in N/mm2 guaranteed by the material standard; 
 R
m = minimum tensile strength in N/mm2 guaranteed by the material standard 
 R
mt = actual tensile strength, in N/mm2; 
 a = calculated minimum thickness of the cylindrical shell wall, in mm; 
 
b = calculated minimum thickness of dished ends, in mm;  D = nominal outside diameter of the container, in mm; 
 R = inside radius of the dished end of th e standard cylindrical  container, in mm; 
 r = inside knuckle of the dished end of th e standard cylindrical  container, in mm; 
 H = outside height of dished part of container end, in mm; 
 
h = height of cylindrical pa rt of dished end, in mm; 
 L = length of container's stre ss-resistant shell, in mm; 
 A = elongation value (per ce nt) of parent material; 
 V
0 = initial volume of the container at the mo ment when the pressure is increased in 
the burst test, in dm3; 
 
V = final volume of the container on bursting, in dm3; 
 g = gravity, in m/s
2; 
 c = shape factor; 
 
Z = stress reduction factor. GSO STANDARD                                                                     GSO  /    
 
 
 771. TECHNICAL REQUIREMENTS 
 1.1. Cylinders covered by this  annex are as follows: 
 
LPG-1 Metal containers LPG-4 All-Composite containers 
 1.2. Dimensions  
For all dimensions without indication of  tolerances, general tolerances of 
EN 22768-1 shall apply. 
 1.3. Materials 
 1.3.1. The material used for the manufacture of  the stress-resistant container shells 
must be steel as specified in Euro norm EN 10120 (however, other materials 
may be used provided that the container ha s the same safety characteristics, to 
be certified by the authorities granting type approval). 
 1.3.2. The parent material refers to the mate rial in the state be fore any specific 
transformation with regards to the manuf acturing process has been carried out. 
 1.3.3. All components of the cont ainer body and all the parts welded thereto must be 
made of mutually compatible materials. 
 1.3.4. The filler materials must be compatible w ith the parent material so as to form 
welds with properties equivalent to those specified for the parent material (EN 288-39). 
 1.3.5. The container manufacturer must obtain and provide:  
(a) for metal containers: chemi cal cast analysis certificates; 
(b) for all-composite containers: chemical resistance analysis certificates 
related to tests performed according to  the requirements of Appendix 6;  
(c) mechanical properties of the materi al in respect of the steels or other 
materials applied for the construction of the parts subject to pressure. 
 1.3.6. The inspection authority must have the opportunity to make independent 
analyses.  These analyses must be carri ed out either on specimens taken from 
the materials as supplied to the container manufactur er or on the finished 
containers. 
 1.3.7. The manufacturer must make available to  the inspection author ity the results of 
metallurgical and mechanical tests and analyses of parent and filler materials carried out on welds and must also provide  it with a description of the welding 
methods and processes which can be rega rded as representative of the welds GSO STANDARD                                                                     GSO  /    
 
 
 78made during production. 
 
1.4. Design temperatures and pressures  1.4.1. Design temperature    
The design operating temperature of the container shall be from -20 °C to 
65 °C.  For extreme operating temperatures exceeding the above-mentioned temperatures special test conditions ar e applicable which shall be agreed upon 
with the competent authority. 
 1.4.2. Design pressure  
The design operating pressure of th e container shall be: 3,000 kPa. 
 
1.5. The heat treatment procedur es, on metal containers on ly, shall be according to 
the following requirements: 
 1.5.1. The heat treatment shall be carrie d out on the parts or on the complete 
container.  
 1.5.2. Those parts of a container having been deformed by more than 5 per cent must 
be submitted to the following heat treatment: normalize. 
 
1.5.3. Containers with a wall thickness ≥ 5 mm must be submitted to the following 
heat treatment: 
 
1.5.3.1. hot-rolled and normalized material:  stress relieve or normalize; 
 1.5.3.2. material of a different kind:  normalize.  1.5.4. The manufacturer must submit the procedure for the heat treatment used.  1.5.5. Localized heat treatment of a completed container is not permitted.  1.6. Calculation of the parts under pressure 
 1.6.1. Calculation of the parts under pressure for metal containers. 
 1.6.1.1. The wall thickness of the cylindrical shel l of the containers must not be less 
than that calculated by the formula: 
 GSO STANDARD                                                                     GSO  /    
 
 
 791.6.1.1.1. Containers without longitudinal welds: 
 
h eh
heh
PRDP
PRDPa+⋅=
+⋅=1500
3/42000 
 
1.6.1.1.2. Containers with longitudinal welds: 
 
h eh
heh
PzRDP
PzRDPa+⋅⋅=
+⋅⋅=1500
3/42000 
 
(i)  z =  0.85 where the manufacturer radiographs each weld intersection and 100 m of the adjacent longitudinal weld  and 50 mm (25 mm each side of the 
intersection) of the adjacent circumferential weld. 
 
This test has to be performed per machine at the beginning and end of each work shift period from continuous production. 
 
(ii)  z =  1 where each weld inte rsection and 100 mm of the adjacent 
longitudinal weld and 50 mm (25 each side  of the intersection) of the adjacent 
circumferential weld is spot radiographed. 
 
This test has to be performed at 10 per cent of the container production: the 
containers to be tested are chosen randomly.  Should these radiograph tests 
reveal unacceptable defects, as defi ned in paragraph 2.4.1.4., all the necessary 
steps must be taken to examine the production run in quest ion and eliminate 
the defects. 
 
1.6.1.2. Dimensions and calculations of ends (s ee figures in Appendix 4 to this annex). 
 1.6.1.2.1. The container ends shall be in one piece, shall encave to the pressure and shall 
have either a torispherical or an el liptical form (examples are given in 
Appendix 5). 
 1.6.1.2.2. The container ends must fulfil the following conditions:  
Torispherical ends 
 
simultaneous limits:  0.003 D ≤ b ≤ 0.08 D 
r ≥ 0.1 D 
R ≤ D 
H ≥ 0.18 D 
r ≥ 2 b 
h ≥ 4 b GSO STANDARD                                                                     GSO  /    
 
 
 80h ≤ 0.15 D (not applicable for contai ners as shown in  Appendix 2 to 
this annex, Figure 2a) 
 
Elliptical ends 
 
simultaneous limits:  0.003 D ≤ b ≤ 0.08 D 
H ≥ 0.18 D 
h ≥ 4 b 
h ≤ 0.15 D (not applicable for contai ners as shown in  Appendix 2 to 
this annex, Figure 2a) 
 
1.6.1.2.3. The thickness of these barre lled ends must not in toto  be less than the figure 
calculated by means of the following formula: 
 
CRDPb
eh
1500⋅=  
    The shape factor C to be used for fu ll ends is given in the table and in the 
graphs contained in Appendix 4 to this annex. 
 
The wall thickness of the cylindrical edge of the ends may not be less or differ 
more than 15 per cent from the smallest wall thickness of the shell. 
 1.6.1.3. The nominal wall thickness of the cylindr ical part and of the barrelled end may 
not, under any circumstances; be less than: 
 
mmD1250+  
 
   with a minimum of 1.5 mm. 
 
1.6.1.4. The shell of the container may be made up of one, two or three parts.  When 
the shell is made up from two or three parts, the longitudinal welds must be 
shifted/rotated with a minimum of 10 times the thickness of the container wall 
(10 ⋅ a).  The ends must be in one piece and convex. 
 
1.6.2. Calculation of the parts under pr essure for all-com posite containers 
  The stresses in the container shall be  calculated for each container type. The 
pressures used for these calculations sha ll be the design pressure and burst test 
pressure.  The calculations shall use suitable analysis techniques to establish 
stress distribution thr oughout the container. 
 
1.7.  Construction and workmanship  GSO STANDARD                                                                     GSO  /    
 
 
 811.7.1. General requirements 
 1.7.1.1. The manufacturer shall demonstrate by having a suitable quality control system 
that he has and maintains the manufactur ing facilities and pr ocesses to ensure 
that containers produced satisfy the requirements of this annex. 
 1.7.1.2. The manufacturer must ensure thro ugh adequate supervision that the parent 
materials and pressed parts used to ma nufacture the containers are free from 
defects likely to jeopardize th e safe use of the containers. 
 1.7.2. Parts subjected to pressure  1.7.2.1. The manufacturer must describe th e welding methods and processes used and 
indicate the inspections car ried out during production. 
 1.7.2.2. Technical welding requirements  
The butt welds must be executed by an automatic welding process. 
 
The butt welds on the stress-resistant shell may not be lo cated in any area 
where there are changes of profile. 
 
Angle welds may not be superimposed on butt welds and must be at least 
10 mm away from them. 
 
Welds joining parts making up the shell of the cont ainer must satisfy the 
following conditions (see figures given as  examples in Appendix 1 of this 
annex): 
 
longitudinal weld:  this weld is execu ted in the form of a butt weld on the 
full section of the material of the wall; 
 
circumferential weld: 
 
this weld is executed in the form of  a butt weld on the full section of the 
material of the wall.  A joggle weld is  considered to be a special type of 
butt weld; 
 
welds of the studded valve plate or ri ng shall be carried out according to 
Appendix 1, Figure 3. 
 
A weld fixing the collar or supports to the container shall be either a butt 
or angle weld. 
 
Welded mounting supports shall be welded in the circumferential way.  The welds shall be strong enough to w ithstand vibration, braking actions GSO STANDARD                                                                     GSO  /    
 
 
 82and outside forces of at l east 30 g in all directions. 
 
In this case of butt welds, the misa lignment of the joint faces may not 
exceed one-fifth of the thickness of the walls (1/5 a). 
 
1.7.2.3. Inspection of welds  
The manufacturer must ensure that the welds show continuous penetration 
without any deviation of the weld seam , and that they are free from defects 
likely to jeopardize the safe use of the container. 
 
For containers in two pieces , a radiographical test has to be performed on the 
circumferential butt welds over 100 mm, with the exception of the welds in conformity with joggle weld on page 1 of  Appendix 1 of this annex.  On one 
container selected at the beginning and end of each shift period from 
continuous production and, in the event of production being interrupted for a 
period of more than 12 hours, the first container welded should also be radiographed. 
 1.7.2.4. Out-of-roundness  
The out-of-roundness of the cylindrical sh ell of the container must be limited 
so that the difference between the maximum and minimum outside diameter of the same cross-section is not more than 1 per cent of the average of those diameters. 
 1.7.3. Fittings 
 1.7.3.1. The supports must be manufactured and attached to the container body in such 
a way as not to cause danger ous concentrations of stre sses or be conducive to 
the collection of water. 
 1.7.3.2. The base of the container must be sufficiently strong and made of metal 
compatible with the type of steel used fo r the container.  The form of the base 
must give the container sufficient stability. 
 
The top edge of the base must be welded  to the container in such a way as not 
to be conducive to the collection of water nor to allow water to penetrate 
between the base and the container. 
 1.7.3.3. A reference mark shall be affixed on the containers to ensure their correct 
installation. 
 1.7.3.4. Where fitted, identification plates mu st be fixed on to the stress resistant shell 
and shall not be removable.  All the necessary corrosion prevention measures must be taken. GSO STANDARD                                                                     GSO  /    
 
 
 83 
1.7.3.5. The container shall have provisions  to mount a gas-tight housing or kind of 
protection device over the container accessories. 
 1.7.3.6. Any other material, however, may be  used for the manufacture of the supports, 
provided that its strength is assured and that all risk of the container end 
corroding is eliminated. 
 1.7.4. Fire protection 
 
1.7.4.1. A container representative of the type  of container, all acce ssories fitted on it 
and any added insulation or protective  material, shall be  covered by a bonfire 
test as specified in paragr aph 2.6. of this annex. 
 2.  TESTS  
Tables 1 and 2 below give an overview of the tests to be performed on the LPG containers on prototypes as well as during the production process according to 
their nature.  All tests shall be pe rformed at ambient temperature of 20 ± 5 °C, 
unless otherwise stated. 
 
Table 1
 — Overview of tests to be performed on metal containers 
 
Test to be performed Production 
Batch tests Number of containers  
to be tested for 
type approval Test description 
Tensile test 1 per batch 2 1 / See para. 2.1.2.2. 
Bend test 1 per batch 2 1 / See para. 2.1.2.3. 
Burst test   2 See para. 2.2. 
Hydraulic test Each 
container 100 % See para. 2.3. 
Bonfire test  1 See para. 2.6. 
Radiographic 
examination 1 per batch 100 % See para. 2.4.1. 
Macroscopic 
examination 1 per batch 2 1 / See para. 2.4.2. 
Inspection of welds 1 per batch 100 % See para. 1.7.2.3. 
Visual inspection of the parts of the container 1 per batch 100 %  
 1
/ These test pieces can be taken from one container 
Note 1 : 6 containers shall be submitted for type approval.   GSO STANDARD                                                                     GSO  /    
 
 
 84Note 2 : On one of these prototypes the volume of the container and the wall thickness of 
each part of the containe r shall be determined. 
 
Table 2  — Overview of tests to be perf ormed on all-composite containers 
 
Test to be performed Production 
Batch tests Number of 
containers  
to be tested for 
type approval Test description 
Burst test  1 per batch 3 See para. 2.2. 
Hydraulic test Each 
container All containers See para. 2.3. 
 
Ambient temperature pressure cycling test 1 per 5 
batches 3 See para. 2.3.6.1.  
High temperature pressure 
cycling test  1 See para. 2.3.6.2. 
External leak test  1 See para. 2.3.6.3. 
Permeation test  1 See para. 2.3.6.4. 
LPG cycling test  1 See para. 2.3.6.5. 
High temperature creep 
test  1 See para. 2.3.6.6.  
Bonfire test  1 See para. 2.6. 
Impact test  1 See para. 2.7. 
Drop test  1 See para. 2.8. 
Boss torque test  1 See para. 2.9. 
Acid environment test  1 See para. 2.10. 
Ultra-violet radiation te st  1 See para. 2.11. 
 2.1. Mechanical tests  
2.1.1. General requirements 
 
2.1.1.1. Frequency of the mechanical tests  
2.1.1.1.1. The frequency of the tests for meta l containers shall be: 1 container from each 
batch during production and for t ype testing, see Table 1. 
 
 Test pieces which are not flat sha ll be flattened by a cold process.  
  In test pieces containing a weld, the weld shall be machined to trim the surplus. 
   
 Metal containers shall be  subjected to the tests as  described in Table 1. 
 GSO STANDARD                                                                     GSO  /    
 
 
 85 Test pieces from  containers with one circumferential weld only (two sections) 
shall be taken from the places shown in Appendix 2, Figure 1. 
 
 Test pieces from  containers with longitudinal a nd circumferential welds (three 
or more sections) shall be taken from  the places shown in Appendix 2, Figure 
2. 
 
2.1.1.1.2.  The frequency of the tests for al l-composite containers shall be: 
 
(a) During production:  1 container from each batch 
(b) For type testing, see Table 2 
 
2.1.1.2. All the mechanical tests for check ing the properties of the parent metal and 
welds of the stress-resistant shells of the cont ainer are carried out on test pieces 
taken from finished containers. 
 
2.1.2. Types of tests and evaluation of test results 
 2.1.2.1. Each sample container is subjected to the following tests:  2.1.2.1.1. Containers with longitudinal and ci rcumferential welds (three sections) on test-
pieces taken from the places shown in Figure 1 of Appendix 2 of this annex: 
 
(a) One tensile test on parent materia l; the test piece to be taken in the 
longitudinal direction (if this is not possible, it may be taken in a 
circumferential direction); 
 
(b) One tensile test on parent material of the bottom; 
 
(c) One tensile test perpendicu lar to the longitudinal weld; 
 
(d) One tensile test perpendicular to the circumferential weld; 
 
(e) One bend test on the longitudinal weld, the inner su rface in tension; 
 
(f) One bend test on the longitudinal weld, the outer su rface in tension; 
 
(g) One bend test on the circumferential weld, the inner surface in 
tension; 
 
(h) One bend test on the circumferential weld, the outer surface in 
tension; and 
 
(i) One macroscopic test of a welded section; 
 
(ml, m2) A minimum of two macroscopi c tests of valve bos s/plate sections GSO STANDARD                                                                     GSO  /    
 
 
 86in case of the sidewall mounted valv es referred to in paragraph 2.4.2. 
below. 
 
2.1.2.1.2. Containers with circumferentia l welds only (two sections) on test-pieces 
taken from the places shown in Figur es 2a and 2b of Appendix 2 to this 
annex: 
 
The tests as specified in  paragraph 2.1.2.1.1. above with the exception of 
(c), (e) and (f) which are not applicable.  The test-piece for the tensile test 
on parent material shall be taken from (a) or (b) as mentioned in 
paragraph 2.1.2.1.1. above. 
 2.1.2.1.3. Test-pieces which are not suffici ently flat must be flattened by cold 
pressing. 
 2.1.2.1.4. In all test pieces containing a weld, the weld is machined to trim the 
surplus. 
 2.1.2.2. Tensile test  2.1.2.2.1. Tensile test on parent metal  
2.1.2.2.1.1. The tensile test shall be carried  out in accordance with Euronorms EN 876, 
EN 895 and EN 10002-1. 
 2.1.2.2.1.2. The values determined for yiel d stress, tensile strengt h and elongation after 
break must comply with the characteristics of the metal as required in 
paragraph 1.3. of this annex. 
 2.1.2.2.2. Tensile test on welds  2.1.2.2.2.1. This tensile test perpendicular to the weld must be carried out on a test-
piece having a reduced cross-section 25 mm in width for a length extending 
up to 15 mm beyond the edges of the weld, as shown in Figure 2 of Appendix 3 to this annex. 
 
Beyond this central part the width of the test-piece must increase 
progressively. 
 2.1.2.2.2.2. The tensile strength value obtai ned must meet the minimum levels required 
by EN 10120. 
 2.1.2.3. Bend test  2.1.2.3.1. The bend test shall be carried  out in accordance with standards ISO 
7438:2000 and ISO 7799:2000 and Euronorm EN 910 for welded parts.  GSO STANDARD                                                                     GSO  /    
 
 
 87The bend tests shall be carried out on the inner surface in tension and the 
outer surface in tension. 
 
2.1.2.3.2. Cracks must not appear in the test-piece when it is bent round a mandrel as 
long as the inside edges are separate d by a distance not greater than the 
diameter of the mandrel + 3a (see Figure 1 in Appendix 3 of this annex). 
 2.1.2.3.3 The ratio (n) between the diameter  of the mandrel and the thickness of the 
test piece must not exceed the values given in the following table: 
 
Actual tensile strength 
R
t in (N/mm2) Value (n) 
up to 440 inclusive 
above 440 to 520 inclusive above 520 2 3 4 
  2.1.2.4. Retesting for the tensile and bend tests  
2.1.2.4.1. Retesting is permitted for the tensile and bend test.  A second test shall 
consist of two test pieces taken from the same container. 
 If the results of these te sts are satisfactory, the fi rst test shall be ignored. 
 In the event where one or both of the retests fail to meet the requirements, the batch shall be rejected. 
 2.2. Burst test under hydraulic pressure  2.2.1. Test conditions 
 
Containers subjected to th is test must bear the inscriptions which it is 
proposed to affix on the section of th e container subjected to pressure, 
 
2.2.1.1. The burst test under hydraulic pre ssure must be carried out with equipment 
which enables the pressure to be in creased at an even rate, until the 
container bursts and the change in pr essure over time to be recorded.  The 
maximum flow rate during the test should not exceed 3 per cent of the capacity of the container per minute. 
 2.2.2. Test interpretation  2.2.2.1. The criteria adopted for the interp retation of the burst test are as follows: 
 
2.2.2.1.1. Volumetric expansion of the me tal container; it equals: volume of water 
used between the time when the pressu re starts to rise and the time of GSO STANDARD                                                                     GSO  /    
 
 93bursting; 
 
2.2.2.1.2. Examination of the tear and the shape of its edges; 
 
2.2.2.1.3. Bursting pressure. 
 2.2.3. Test acceptance conditions  2.2.3.1. The measured bursting pressure (P
r) must not under any circumstances be 
less than 2.25 ⋅ 3,000 = 6,750 kPa. 
 2.2.3.2. The specific change in the volum e of the metal container at the time of 
bursting must not be less than: 
 
20 per cent if the length of the metal c ontainer is greater than the diameter; 
 
17 per cent if the length of the metal container is equal to or less than the diameter. 
 
8 per cent in the case of  a special metal container as shown in Appendix 5, 
page 1, Figures A, B and C. 
 2.2.3.3. The burst test must not cause  any fragmentation of the container. 
 2.2.3.3.1. The main fracture must not show  any brittleness, i.e. the edges of the 
fracture must not be radial but must be  at an angle to a diametrical plane 
and display a reduction of ar ea throughout their thickness. 
 2.2.3.3.2. For metal containers the fracture mu st not reveal an inherent defect in the 
metal.  The weld must be at least as strong as the original metal but preferably stronger. 
  For all-composite containers, the fractu re shall not reveal any defects in the 
structure. 
 2.2.3.4. Retesting for the burst test 
  Retesting is permitted for the burst test.  A second burst test shall be 
performed on two containers which have  been produced successively to the 
first container within the same batch.  If the results of these te sts are satisfactory, the fi rst test shall be ignored. 
 In the event where one or both of the retests fail to meet the requirements, the batch shall be rejected. 
  GSO STANDARD                                                                     GSO  /    
 
 942.3. Hydraulic test 
 2.3.1. The containers representative of the type of container submitted for 
approval (without accessories but with the outlets closed off) shall withstand an inner hydraulic pressure  of 3,000 kPa without leakages or 
becoming permanently distorted, accor ding to the following requirements: 
 2.3.2. The water pressure in the containe r must increase at an even rate until the 
test pressure of 3,000 kPa is reached. 
 2.3.3. The container must remain under th e test pressure long enough to make it 
possible to establish that  the pressure is not falling off and that the 
container can be guaranteed leakproof. 
 2.3.4. After the test the container must show no signs of permanent deformation.  2.3.5. Any container tested which does not pass the test must be rejected. 
 2.3.6. Additional hydraulic tests to be  performed on all-composite containers 
 2.3.6.1. Ambient temperature pressure cycling test  2.3.6.1.1. Test procedure  
The finished container shall be pre ssure cycled to a maximum of 20,000 
cycles, according to the following procedure: 
 
(a) fill the container to be tested w ith a non-corrosive fluid such as oil, 
inhibited water or glycol; 
(b) cycle the pressure in the contai ner between not more than 300 kPa and 
not less than 3,000 kPa at a rate not  to exceed 10 cycles per minutes. 
This cycle shall be performed at least 10,000 times and continued until 
20,000 times unless a leak before break appears; 
(c) the number of cycles to failure shall be reported, along with the 
location and description of the failure initiation. 
 2.3.6.1.2. Test interpretation
 
 
Before reaching 10,000 cycles, the c ontainer shall not fail or leak. 
After completing 10,000 cycles, the c ontainer may leak before break. 
 
2.3.6.1.3. Retesting  
 
Retesting is permitted for the ambient temperature pressure cycling test.  
 GSO STANDARD                                                                     GSO  /    
 
 95A second test shall be performed on two containers wh ich have been 
produced successively to the first container within the same batch. 
 
If the results of these te sts are satisfactory, the fi rst test shall be ignored. 
 
In the event where one or both of the retests fail to meet the requirements, 
the batch shall be rejected. 
 2.3.6.2. High temperature pressure cycling test  2.3.6.2.1. Test procedure   
Finished containers sha ll be cycle tested, without showing evidence of 
rupture, leakage, or fibr e unravelling, as follows: 
 (a) Fill the container to be tested w ith a non-corrosive fl uid such as oil, 
inhibited water or glycol; 
 (b) Condition for 48 hours at 0 kPa,  65 °C, and 95 per cent or greater 
relative humidity.  
 (c) Hydrostatically pressurize for 3, 600 cycles not exceeding 10 cycles per 
minute, between not more than 300 kPa and not less than 3,000 kPa at 
65 °C and 95 per cent humidity; 
 Following the pressure cycling at high temperature, containers shall be 
submitted to the external leak test and then hydrostatically pressurized to 
failure in accordance with the burst test procedure. 
 
2.3.6.2.2. Test interpretation 
  The container shall comply with the external leak test requirements as 
defined in paragraph 2.3.6.3. 
  The container shall achieve a minimum burst pressure of 85 per cent of the 
burst pressure. 
 2.3.6.2.3. Retesting  
 Retesting is permitted for the high temperature pressure cycling test.  A second test shall be performed on two containers wh ich have been 
produced successively to the first container within the same batch.  If the results of these te sts are satisfactory, the fi rst test shall be ignored. 
 GSO STANDARD                                                                     GSO  /    
 
 96In the event where one or both of the retests fail to meet the requirements, 
the batch shall be rejected. 
 
2.3.6.3. External leak test  
 
2.3.6.3.1. Test procedure  
 
While under 3,000 kPa pressure, the cont ainer shall be submerged in soapy 
water to detect l eakage (bubble test). 
 
2.3.6.3.2. Test interpretation 
 
The container shall not show any leakage. 
 
2.3.6.3.3. Retesting 
 
Retesting is permitted for the external leak test.  A second test shall be performed on two containers wh ich have been 
produced successively to the first container within the same batch. 
 
If the results of these tests are satisfac tory, the first test shall be ignored. In 
the event where one or both of the retest s fail to meet the requirements, the 
batch shall be rejected. 
 2.3.6.4. Permeation test 
 
2.3.6.4.1. Test procedure  
All the tests shall be performed at 40 °C on a container fuelled with 
commercial propane at 80 per cent of its water capacity. 
 
The test shall be held during at least 8 weeks until the steady state permeation of the structure is obs erved during at least 500 hours. 
 
 Then, the rate of the containe r weight loss shall be measured. 
  The graph of mass change per num ber of days sha ll be recorded. 
 2.3.6.4.2. Test interpretation  
The rate of mass loss shall be less than 0.15 g/hour. 
 2.3.6.4.3. Retesting 
 
 Retesting is permitted for the permeation test. GSO STANDARD                                                                     GSO  /    
 
 97 
A second test shall be performed on two containers wh ich have been 
produced successively to the first container within the same batch. 
 If the results of these test s are satisfactory, the first test shall be ignored.  In 
the event where one or both of the retest s fail to meet the requirements, the 
batch shall be rejected. 
 2.3.6.5. LPG cycling test
 
 
2.3.6.5.1. Test procedure  
A container having successfully passe d the permeation test shall be 
submitted to an ambient temperature pressure cycling test according to the 
requirements of paragraph 2.3.6.1. of this annex.  
The container shall be sectioned and the liner / end boss interface shall be 
inspected. 
 2.3.6.5.2. Test interpretation  
The container shall comply with the ambient temperature pressure cycling test requirements. 
 
Inspection of the liner / end boss interf ace of the container shall not reveal 
any evidence of deterioration, such as fatigue cracking or electrostatic 
discharge.  
2.3.6.5.3. Retesting   Retesting is permitted for the LPG cycling test.  
A second test shall be performed on two containers wh ich have been 
produced successively to the first container within the same batch.  If the results of these te sts are satisfactory, the fi rst test shall be ignored. 
 In the event where one or both of the retests fail to meet the requirements, 
the batch shall be rejected. 
 
2.3.6.6. High temperature creep test  2.3.6.6.1. General  GSO STANDARD                                                                     GSO  /    
 
 98This test shall only be performed on al l-composite containers with a resin 
matrix having a glass transition temperature (T G) below the design 
temperature +50 °C. 
 
2.3.6.6.2. Test procedure 
 
One finished container shall be tested as follows: 
 
(a) The container shall be pressurized to 3,000 kPa and held at a 
temperature defined according the tabl e on the basis of the test period 
duration: 
 
Table 3 : Test temperature relating to the High temperature creep test 
duration 
 
T (°C) Exposure time (h) 
100 200 
95 350 
90 600 
85 1000 
80 1800 
75 3200 
70 5900 
65 11000 
60 21000 
 
(b) The container shall be submitte d to an external leak test.  
 
2.3.6.6.3.  Test interpretation 
 
The maximum allowed volume increase is  5 per cent.  The container shall 
meet the requirements of the external leak  test as defined in paragraph 2.4.3. 
of this annex and the burst test as defi ned in paragraph 2.2. of this annex. 
 2.3.6.6.4. Retesting  
Retesting is permitted for the high temperature creep test. A second test shall be performed on two containers wh ich have been 
produced successively to the first container within the same batch. 
 
If the results of these test s are satisfactory, the first test shall be ignored.   
 In the event where one or both of the retests fail to meet the requirements, 
the batch shall be rejected. 
 2.4. Non-destructive examination GSO STANDARD                                                                     GSO  /    
 
 99 
2.4.1. Radiographic examination  2.4.1.1. Welds must be radiographed in compliance with ISO specification R 1106, 
using classification B. 
 2.4.1.2. When a wire-type indicator is used, the smallest diameter of the wire visible 
may not exceed the value of 0.10 mm. 
  When a stepped and holed type indi cator is used, the diameter of the 
smallest hole visible may not exceed 0.25 mm. 
 2.4.1.3. Assessment of the weld radiographs  must be based on the original films in 
compliance with the practice recommended in standard ISO 2504, paragraph 6. 
 2.4.1.4. The following defects are not acceptable:   Cracks, inadequate welds or inadequate penetration of the weld.  
2.4.1.4.1. For the container wall thickness ≥ 4 mm, the inclusions listed below are 
regarded as acceptable: 
 
 Any gas inclusion measuring not more than a/4 mm;   Any gas inclusion measuring more th an a/4 mm but not more than a/3 mm, 
which is more than 25 mm away from  other gas inclusion measuring more 
than a/4 mm and measuring not more than a/3 mm; 
 
 Any elongated inclusion or any group of  rounded inclusions in a row where 
the length represented (over a weld le ngth of 12a) is not greater than 6 mm; 
 
Gas inclusions over any 100 mm weld lengt h, where the tota l area of all the 
figures is not greater than 2a mm
2. 
 
2.4.1.4.2. For the container wall thickness < 4 mm, the inclusions listed below are 
regarded as acceptable: 
 
Any gas inclusion measuring not more than a/2 mm; 
 
Any gas inclusion measuring more than a/2 mm but not more than a/1.5 
mm, which is more than 25 mm away from other gas inclusion measuring 
more than a/2 mm and measur ing not more than a/1.5 mm; 
 
Any elongated inclusion or any group of  rounded inclusions in a row where 
the length represented (over a weld le ngth of 12a) is not greater than 6 mm; GSO STANDARD                                                                     GSO  /    
 
 100 
Gas inclusions over any 100 mm weld lengt h, where the tota l area of all the 
figures is not greater than 2a mm2. 
 
2.4.2. Macroscopic examination 
 
The macroscopic examination of a full tr ansverse section of the weld must 
show a complete fusion on the surface treated with any acid from the 
macro-preparation and must not show any assembly fault or a significant 
inclusion or other defects. 
 
In case of doubt, a microscopic examin ation should be made of the suspect 
area. 
 2.5. Examination on the outside of the weld for metal containers  
2.5.1. This examination is carried out  when the weld has been completed. 
 
The welded surface examined must be well illuminated, and must be free 
from grease, dust, scale residue or  protective coating of any kind. 
 
2.5.2. The fusion of the welded metal with the parent metal must be smooth and 
free from etching.  There must be no cracks, notching or porous patches in 
the welded surface and the surface adjacent to the wall.  The welded surface must be regular and even.  Where a butt weld has been used, the excess thickness must not exceed 1/4 of the width of the weld. 
 2.6. Bonfire test 
 
2.6.1. General  
The bonfire test is designe d to demonstrate that a container complete with 
the fire protection system, specified in the design, will prevent the burst of 
the container when tested under th e specified fire conditions.  The 
manufacturer shall describe the behavi our of the complete fire protection 
system including the designed drop to atmospheric pressure.  The 
requirements of this test shall be deemed to be fulfilled for any container 
having the following characteristics in common with the parent container: 
 
(a) same type approval owner, 
(b) same shape (cylindrical, special shape), 
(c) same material, 
(d) same or greater wall thickness, 
(e) same or smaller diameter  (cylindrical container), 
(f) same height or smaller hei ght (special container shape), GSO STANDARD                                                                     GSO  /    
 
 101(g) same or smalle r external surface, 
(h) same configuration of accesso ries fitted to the container. 1/ 
 
2.6.2. Container set-up 
 
 (a) The container shall be placed in the designed position by the 
manufacturer with the container bottom approximately 100 mm above 
the fire source. 
 (b) Shielding shall be used to prevent direct flame impingement on the 
fusible plug (PRD) if present.  The shielding shall not be in direct contact with the fu sible plug (PRD). 
 (c) Any failure during the te st of a valve, fitting or tubing that is not part of 
the intended protection system for the design shall invalidate the result. 
 (d) Containers with a length of less than 1.65 m:  The centre of the 
container shall be positioned over the centre of the fire source. 
  Containers with a length equal to or larger than 1.65 m:  If the container 
is fitted with a pressure relief devi ce at one side, the fire source shall 
commence at the opposite side of the container.  If the container is fitted with pressure relief devices at both sides, or at more than one location along the length of the contai ner, the centre of the fire source 
shall be centred midway between the pressure relief devices that are separated by the greate st horizontal distance. 
 2.6.3. Fire source  
A uniform fire source of 1.65 m length shall provide direct flame 
impingement on the container surf ace across its entire diameter. 
Any fuel may be used for the fire s ource provided that it supplies uniform 
heat sufficient to maintain the sp ecified test temperatures until the 
container is vented. The arrangement of the fire shall be recorded in 
sufficient detail to ensure that the ra te of heat input to  the container is 
reproducible. Any failure or inconsistenc y of the fire source during a test 
shall invalidate the result. 
 2.6.4. Temperature and pressure measurements   During the bonfire test the following items shall be measured:  
                                                
 
1/ Additional accessories, modifications and exte nsions of the accessories fitted to the 
container is possible without re testing, if notified to the ad ministrative department which 
approved the container, considered to be unlikel y to have an appreciabl e adverse effect.  The 
administrative department may require a furt her test report from the technical service 
responsible.  The container and its configur ations of accessories will be indicated in 
Appendix 1 to Annex 2B. GSO STANDARD                                                                     GSO  /    
 
 102 (a) The fire temperature just below the container, along the bottom of the 
container, at minimum two locatio ns, not more than 0.75 m apart; 
 (b) The wall temperature in the bottom of the container; 
 (c) The wall temperature within 25 mm from the pressure relief device; 
 (d) The wall temperature on the top of the container, in the centre of the 
fire source; 
 (e) The pressure inside the container. 
  Metallic shielding shall be used to prevent direct flame impingement on the 
thermocouples. Alternatively, thermocoupl es may be inserted into blocks of 
metal, measuring less than 25 mm
2.  During the test the thermocouple 
temperatures and the contai ner pressure sha ll be recorded at intervals of 
2 seconds or less. 
 2.6.5. General test requirements   (a) Container shall be filled w ith 80 per cent in volume of LPG 
(commercial fuel) and tested in the horizontal position at working 
pressure; 
 (b) Immediately following the igni tion, the fire shall produce flame 
impingement on the surface of the c ontainer, along 1.65 m length of 
the fire source across the container; 
 (c) Within 5 minutes of ignition at least one thermocouple shall indicate 
the temperature of fire just below the container of at least 590 °C.  
This temperature shall be maintained for the remaining duration of the test, namely until when no overpressure is present in the container; 
 (d) The severity of the test conditi ons shall not be mitigated by ambient 
conditions (e.g. rain, moderate/high wind etc.). 
 2.6.6. Test results:   (a) A burst of the container sh all invalidate the test result. 
 (b) A pressure of more than 3,700 kPa,  i.e. 136 per cent of the set pressure 
of the PRV (2,700 kPa), during the test  shall invalidate the test result. 
  A pressure between 3,000 and 3,70 0 kPa shall only i nvalidate the test 
result in case visible plastic deformation is observed. 
 (c) In case the behaviour of the pr otection system does not comply with 
the specification of the manufacturer  and it leads to a mitigating test 
condition the result shall be invalidated. 
 (d) For a composite container a rel ease of LPG via the surface is accepted 
in case of a controlled release.  A release of gaseous LPG within 2 
minutes after the start of the test or  a release capacity of more than 30 
litres per minute shall invalidate the test result. 
 (e) The results shall be presented in a test summary and shall include the 
following data for each container as a minimum: 
  - Description of the container configuration. GSO STANDARD                                                                     GSO  /    
 
 103  - Photo of the container set-up and PRD. 
  - Applied method including time interval between measurements. 
  - The elapsed time from ignition of the fire to the start of venting of 
LPG and actual pressure . 
  - Time to reach atmospheric pressure.   - Pressure and temperature diagrams.  2.7.  Impact test  2.7.1.  General
 
 
At the choice of the manufacturer, all the impact tests may be carried out on 
one container or each may be carri ed out on a differe nt container.  
 2.7.2.  Test procedure
 
 
For this test, the fluid medium shall be water/glycol mixture or another 
liquid having a low freezing point whic h does not change the properties of 
the container material. 
 
A container filled with the fluid medium to the weight that equals the filling 
with 80 per cent of LPG with a refere nce mass of 0.568 kg/l, is projected, 
parallel to the length axle (x-axis in Figure 1) of the vehicle in which it is intended to be fitted at a velocity, V of 50 km/h, against a solid wedge, fixed 
horizontally, perpendicular to th e movement of the container.  
 
The wedge shall be installed so that the centre of gravity (c.g.) of the 
container hits the centre of the wedge.  The wedge shall have an angle α of 90 degrees and the point of impact shall 
be rounded with a maximum radius of 2.5 mm.   The length of the wedge L, shall be at least equal to the width of the 
container in respect to its movement during the test. The height H of the 
wedge shall be at least 600 millimetres  Figure 1
 - description of the impact test procedure: 
 
 
 
   
 
  
α v z x 
y 
z
H H r=2.5 mm GSO STANDARD                                                                     GSO  /    
 
 104 
       
Note
: c.g. = center of gravity 
 
In the case where a container can be in stalled in more than one position in 
the vehicle, each position shall be tested. 
 After this test, the container shall be submitted to an external leak test as defined in paragraph 2.3.6.3. of this annex. 
 2.7.3. Test interpretation   The container shall comply with the external leak test requirements as 
defined in paragraph 2.3.6.3. of this annex. 
 2.7.4. Retesting 
 
 Retesting is permitted for the impact test.   
A second test shall be performed on two containers wh ich have been 
produced successively to the first container within the same batch.  If the results of these te sts are satisfactory, the fi rst test shall be ignored. 
In the event where one or both of the retests fail to meet the requirements, 
the batch shall be rejected. 
 2.8.  Drop Test  2.8.1. Test procedure 
 
One finished container shall be drop tested at ambient temperature without 
internal pressurization or attached  valves. The surface onto which the 
containers are dropped shall be a sm ooth, horizontal concrete pad or 
flooring. The drop height (Hd) shal l be 2 m (measured to th e lowest point of the 
container).  
The same empty container shall be dropped: 
 
 - in a horizontal position, L c.g.c.g.GSO STANDARD                                                                     GSO  /    
 
 105 - vertically on each end,  
 - at an angle of 45°.   Following the drop test, the containers shall be submitted to an ambient 
temperature pressure cycling test  according the requirements of 
paragraph 2.3.6.1. of this annex. 
 2.8.2. Test interpretation  
The containers shall comply with the requirements of the ambient 
temperature pressure cycling test ac cording the requirements of paragraph 
2.3.6.1. of this annex. 
 2.8.3. Retesting  
Retesting is permitted for the drop test.  A second test shall be performed on two containers wh ich have been 
produced successively to the first container within the same batch.  If the results of these te sts are satisfactory, the fi rst test shall be ignored. 
 In the event where one or both of the retests fail to meet the requirements, 
the batch shall be rejected. 
 2.9. Boss torque test 
 
2.9.1. Test procedure 
 
The body of the container shall be restra ined against rotatio n and a torque of 
2 times the valve or PRD installation  torque specified by the manufacturer 
shall be applied to each end boss of th e container, first in the direction to 
tighten a threaded connection, then in the untightening direction, and finally 
again in the tightening direction.  The container shall then be subjected to an external leak te st in accordance 
with the requirements shown in pa ragraph 2.3.6.3 of this annex. 
 GSO STANDARD                                                                     GSO  /    
 
 1062.9.2. Test interpretation 
 
The container shall comply with the requi rements of the extern al leak test as 
shown in paragraph 2.3.6.3. of this annex.  
2.9.3. Retesting  
Retesting is permitted for the boss torque test.    A second test shall be performed on two containers wh ich have been 
produced successively to the first container within the same batch.  If the results of these te sts are satisfactory, the fi rst test shall be ignored. 
 In the event where one or both of the retests fail to meet the requirements, 
the batch shall be rejected. 
 2.10. Acid environment test  2.10.1. Test procedure  
A finished container shall be ex posed for 100 hours to a 30 per cent 
sulphuric acid solution (battery acid with specific gravity of 1.219) while 
pressurized to 3,000 kPa.  During the te st, a minimum of 20 per cent of the 
total area of the container has to be covered by the sulphur ic acid solution. 
 
Then, the container shall be submitted to a burst test as defined in 
paragraph 2.2. of this annex. 
 
2.10.2. Test interpretation  
The burst pressure measured shall be at least 85 per cent of the container 
burst pressure. 
 2.10.3. Retesting  
Retesting is permitted for the acid environment test.    A second test shall be performed on two containers wh ich have been 
produced successively to the first container within the same batch.  If the results of these te sts are satisfactory, the fi rst test shall be ignored. 
 In the event where one or both of the retests fail to meet the requirements, 
the batch shall be rejected. 
 GSO STANDARD                                                                     GSO  /    
 
 1072.11. Ultra-violet (UV) test 
 2.11.1. Test
 procedure 
 
When the container is directly subjec ted to sunlight (also behind glass), UV-
radiation might degrade polymeric mate rials. Therefore, the manufacturer 
has to prove the ability of the outer layer material to withstand the UV-radiation during his lif etime of 20 years. 
 
(a) If the outer layer has a mechan ical (load carrying) function, the 
container shall be burst tested according to the requirements of 
paragraph 2.2. of this annex, af ter exposing to a representative UV-
radiation; 
 
(b) If the outer layer has a protecti ve function, the ma nufacturer has to 
prove that the coating remains inte ger within 20 year s, in order to 
protect the under-laying structural layers from a representative UV-
radiation. 
 2.11.2. Test interpretation  
When the outer layer has a mechanical function, the container shall comply 
with the burst test requirements as define d in  paragraph 2.2. of this annex. 
 2.11.3. Retesting  
Retesting is permitted for the ultra-violet test.    A second test shall be performed on two containers wh ich have been 
produced successively to the first container within the same batch.  
If the results of these te sts are satisfactory, the fi rst test shall be ignored. 
 
 In the event where one or both of the retests fail to meet the requirements, 
the batch shall be rejected. 
 GSO STANDARD                                                                     GSO  /    
 
 108Annex 10 - Appendix 1  
 
 
Figure 1 :  Types of main longitudinal butt welds 
Figure 2 :  Circumferential butt weld GSO STANDARD                                                                     GSO  /    
 
 109 
 
                        
 
 
         
Figure 3
:  Examples of welded studded plates 
GSO STANDARD                                                                     GSO  /    
 
 110 
                         
 
 
       
Figure 4
:  Examples of welded rings with flange 
 
GSO STANDARD                                                                     GSO  /    
 
 111Annex 10 - Appendix 2  
 
 (a) tensile test on parent material (b) tensile test on parent material of the bottom (c) tensile test on a longitudinal weld (d) tensile test on a circumferential weld (e) bend test on a longitudinal weld , the inner surf ace in tension 
(f) bend test on a longitudinal weld , the outer surf ace in tension 
(g) bend test on a circumferential weld, the inner surface in tension 
(h) bend test on a circumferential weld, the outer surface in tension 
(m1, m2) macrosections through valve boss/ plate welds (side-mounted valve block) 
 
Figure 1
:  Containers with longitudinal and circum ferential welds, Location of test-pieces 
GSO STANDARD                                                                     GSO  /    
 
 112 
  
 
 
 
(a) or (b) tensile test on parent material (d) tensile test on a circumferential weld (g) bend test on a circumferential weld, the inner surface in tension 
(h) bend test on a circumferential weld, the outer surface in tension 
(m1, m2) macrosections through valve boss/ plate welds (side-mounted valve block) 
 
Figure 2a
: Containers with circumferential we lds only and side-mounted valve blocks; 
Location of test-pieces 
GSO STANDARD                                                                     GSO  /    
 
 113 
                    (m1, m2) macrosections th rough valve boss/plate welds 
(Refer to Figure 2a for othe r locations of test-pieces) 
 Figure 2b
: Containers with circumferential welds onl y and valve boss/plate fitted to the end. 
 GSO STANDARD                                                                     GSO  /    
 
 114 
 
Annex 10 - Appendix 3  
 
 
 
   
 
      
 
        
Figure 1
:  Illustration of bend test GSO STANDARD                                                                     GSO  /    
 
 115 
                         
Figure 2
:  Test piece for tensile test perpendicular to the weld 
 
 
 GSO STANDARD                                                                     GSO  /    
 
 116Annex 10 - Appendix 4  
 
Note : For torispherical ends 
 
 
 
 Relationship between H/D and shape factor C 
 GSO STANDARD                                                                     GSO  /    
 
 117 
                         
 
 
      
Values of shape factor C for H/D between 0.20 and 0.25 
11.5
1.41.31.2
1.1
0.2 0.21 0.22 0.23 0.24 0.25b/D
0.005
0.010.0075
0.02
0.03
0.04C
H/DGSO STANDARD                                                                     GSO  /    
 
 118Relationship between H/D and shape factor C 
 
                        
 
 
          
Values of shape factor C for H/D between 0.25 and 0.50 
 GSO STANDARD                                                                     GSO  /    
 
 119Annex 10 - Appendix 5  
 
EXAMPLES OF SPECIAL VESSELS GSO STANDARD                                                                     GSO  /    
 
 120 GSO STANDARD                                                                     GSO  /    
 
 121Annex 10 – Appendix 6  
 
MATERIAL TEST METHODS 
  
1. Chemical resistance  
 
Materials used in an all-composite containe r must be tested accord ing to standard ISO 
175 for 72 hours at room temperature. 
Demonstrating the chemical resistance by usi ng data from literature is also allowed. 
 Compatibility with the following media shall be checked: 
(a) brake fluid; 
(b) window cleaner; (c) cooling liquid; (d) non-leaded petrol; 
(e) solution of deionized water, sodium chloride (2.5 % by mass ± 0.1 %), (calcium 
chloride (2.5 % by mass ± 0.1 %) and sulphuric aci d sufficient to achieve a 
solution of pH 4.0 ± 0.2. 
 
Test acceptance criteria
: 
 
(a) Elongation: 
The elongation of a thermoplastic material , after testing, mu st be at least 
85 per cent of the init ial elongation. The elonga tion of an elastomer, after testing, 
must be at least larger than 100 per cent. 
 
(b) For structural components (e.g., fibres): 
The residual strength for a structural component after testing must be at least 
80 per cent of the origin al tensile strength.  
 
(c) Non-structural components (e.g., coating): 
 There are no visual cracks allowed. 
 
2. Composite structure 
 
(a) Fibres embedded in a matrix 
 
 Tensile properties:   ASTM  3039  Fiber-resin composites 
ASTM D2343  Glass, Aramid 
(tens.prop.yarns glass) 
ASTM D4018.81  Carbon 
(tens.prop.continuous 
filament) with special 
remark for the matrix 
 GSO STANDARD                                                                     GSO  /    
 
 122Shear properties: ASTM D2344 (Interlaminar shear 
 strength of parallel 
 fibre composite by 
short beam method) 
 
(b) Dry fibres on an isotensoid shape 
 
 Tensile properties:   AS TM D4018.81 Carbon (continuous 
filament),  other fibres. 
 
3. Protective coating 
 
UV-radiation degrades polymeric material wh en directly subjected to the sunlight. 
Depending on the installation, the manufacturer ha s to proof a "safe life" for the coating.  
 
4. Thermoplastic components  
The Vicat softening temperature of a th ermoplastic component must be above 70
 °C.  
For structural components, the Vicat soft ening temperature must be at least 75 °C. 
 
5. Thermoset components 
 
The Vicat softening temperature of a ther mo-set component must be above 70 °C. 
 
6. Elastomeric components 
 
The glass transition temperature (Tg) of an  elastomer component must be lower than 
-40 °C.  The glass transition temperature sh all be tested accordi ng ISO 6721 "Plastics - 
Determination of dynamic mechanical propertie s".  The Tg-onset is derived from the 
plotted diagram storage modulus versus te mperature by determining the temperature, 
where the two tangents, which are representi ng the slopes of the diagram before and 
after the dramatic loss of stiffness, intersects. 
 
 GSO STANDARD                                                                     GSO  /    
 
 123Annex 11  
 
PROVISIONS REGARDING THE APPROVAL  OF GAS INJECTION DEVICES, 
OR GAS MIXING PIECES, OR INJECTORS AND THE FUEL RAIL 
 
 1. Gas injection device or injector 
 
1.1. Definition:  see paragrap h 3.10. of this Regulation. 
 1.2. Component classification (accordin g to Figure 1, para. 2.): Class 1. 
 1.3. Classification pressure: 3,000 kPa.  
1.4. Design temperatures:  
 
-20 °C to 120 °C For temperatures exceeding the above -mentioned values, special tests 
conditions are applicable. 
 1.5. General design rules:  
Paragraph 5.15.2., Provisions rega rding the electrical insulation. 
Paragraph 5.15.2.1., Provisions re garding the insulation class. 
Paragraph 5.15.3.1., Provisions wh en the power is switched off. 
Paragraph 5.15.4.1., Heat exchange medium (compatibility and pressure 
requirements). 
 1.6. Applicable test procedures: 
 
Over pressure test Annex 15, para. 4 
 External leakage Annex 15, para. 5  High temperature Annex 15, para. 6  Low temperature Annex 15, para. 7  LPG compatibility Annex 15, para. 11 **
/ 
Corrosion resistance Annex 15, para. 12 * / 
 Resistance to dry heat Annex 15, para. 13 ** / 
 Ozone ageing Annex 15, para. 14 ** / 
 Creep Annex 15, para. 15 ** / 
 Temperature cycle Annex 15, para. 16 ** / 
 
2. Gas injection device or gas mixing piece  
 
2.1. Definition:  see paragrap h 3.10. of this Regulation. 
 2.2. Component classification (according to Figure 1, para. 2.): GSO STANDARD                                                                     GSO  /    
 
 124 
Class 2: for the part with a maximum regulated pressure during operation of 
450 kPa. 
Class 2A: for the part with a maximum regulated pressure during operation of 
120 kPa. 
 2.3. Classification pressure:  
Parts of Class 2: 450 kPa. Parts of Class 2A: 120 kPa. 
 2.4. Design temperatures:   
-20 °C to 120 °C, when the fuel pump is mounted outside the container. 
For temperatures exceeding the above -mentioned values, special tests 
conditions are applicable. 
 2.5. General design rules:  
Paragraph 5.15.2., Provisions rega rding the electrical insulation. 
Paragraph 5.15.2.1., Provisions re garding the insulation class. 
Paragraph 5.15.3.1., Provisions wh en the power is switched off. 
Paragraph 5.15.4.1., Heat exchange medium (compatibility and pressure 
requirements). 
 2.6. Applicable test procedures: 
 
Over pressure test Annex 15, para. 4 
 External leakage Annex 15, para. 5 
 High temperature Annex 15, para. 6  Low temperature Annex 15, para. 7  LPG compatibility Annex 15, para. 11 **
/ 
Corrosion resistance Annex 15, para. 12 * / 
 
3. Fuel rail 
 
3.1. Definition:  see paragrap h 3.18. of this Regulation. 
 3.2. Component classification (according to Figure 1, para. 2.): 
 
Fuel rails can be of Class 1, 2 or 2A. 
 
3.3. Classification pressure:  
Parts of Class 1: 3,000 kPa. 
 Parts of Class 2:    450 kPa. GSO STANDARD                                                                     GSO  /    
 
 125 Parts of Class 2A:    120 kPa. 
 3.4. Design temperatures:   
-20 °C to 120 °C For temperatures exceeding the above -mentioned values, special tests 
conditions are applicable. 
 3.5. General design rules: (not used)  3.6. Applicable test procedures:  3.6.1. For fuel rails of Class 1:  
Over pressure test Annex 15, para. 4 
 External leakage Annex 15, para. 5  High temperature Annex 15, para. 6  Low temperature Annex 15, para. 7  LPG compatibility Annex 15, para. 11 **
/ 
Corrosion resistance Annex 15, para. 12 * / 
 Resistance to dry heat Annex 15, para. 13 ** / 
 Ozone ageing Annex 15, para. 14 ** / 
 Creep Annex 15, para. 15 ** / 
 Temperature cycle Annex 15, para. 16 ** / 
 
3.6.2. For fuel rails of Class 2 and/or 2A: 
 
Over pressure test Annex 15, para. 4 
 External leakage Annex 15, para. 5 
 High temperature Annex 15, para. 6  Low temperature Annex 15, para. 7  LPG compatibility Annex 15, para. 11 **
/ 
Corrosion resistance Annex 15, para. 12 * / 
_________________ 
*/ Only for metallic parts. 
**/ Only for non-metallic parts. 
 E/ECE/324 
E/ECE/TRANS/505 } Rev.1/Add.66/Rev.2 
Regulation No. 67   
page 126 Annex 12   
 
 126Annex 12
 
 
PROVISIONS REGARDING THE APPROVAL  OF THE GAS DOSAGE UNIT WHEN 
NOT COMBINED WITH THE GAS INJECTION DEVICE(S) 
1. Definition:  see paragrap h 3.11. of this Regulation. 
2. Component classification (according to Figure 1, para. 2.): 
Class 2: for the part with a maximum regulated pressure during operation of 
450 kPa. Class 2A: for the part with a maximum regulated pressure during operation of 
120 kPa. 
3. Classification pressure: 
Parts of Class 2: 450 kPa. Parts of Class 2A: 120 kPa. 
4. Design temperatures:  
-20 °C to 120 °C For temperatures exceeding the above -mentioned values, special tests 
conditions are applicable. 
5. General design rules: 
Paragraph 5.15.2., Provisions rega rding the electrical insulation. 
Paragraph 5.15.3.1., Provisions on valv es activated by electrical power. 
Paragraph 5.15.4., Heat exchange me dium (compatibility and pressure 
requirements). Paragraph 5.15.5., Overpressure bypass security. 
6. Applicable test procedures: 
Over pressure test Annex 15, para. 4 
 External leakage Annex 15, para. 5 
 High temperature Annex 15, para. 6  Low temperature Annex 15, para. 7  LPG compatibility Annex 15, para. 11 **
/ 
Corrosion resistance Annex 15, para. 12 * / 
Remarks : 
The parts of the gas dosage unit (Class 2 or 2A) sh all be leakproof with the outlet(s) of that 
part closed. 
For the overpressure test all the outlets includ ing those of the coolan t compartment shall be 
closed off. 
__________________ *
/ Only for metallic parts. 
**/ Only for non-metallic parts.GSO STANDARD                                                                     GSO  /    
 
 127Annex 13  
 
PROVISIONS REGARDING THE APPRO VAL OF THE PRESSURE AND/OR 
TEMPERATURE SENSOR 
 
1. Definition:  
Pressure sensor:  see paragra ph 3.13. of this Regulation. 
Temperature sensor:  see paragr aph 2.13. of this Regulation. 
 2. Component classification (according to Figure 1, para. 2.):  
Pressure and temperature sensors can be of Class 1, 2 or 2A. 
 
3. Classification pressure: 
 
Parts of Class 1: 3,000 kPa. Parts of Class 2:    450 kPa. Parts of Class 2A:    120 kPa. 
 4. Design temperatures:   
-20 °C to 120 °C For temperatures exceeding the above -mentioned values, special tests 
conditions are applicable. 
 
5. General design rules: 
 
Paragraph 5.15.2., Provisions rega rding the electrical insulation. 
Paragraph 5.15.4.1., Heat exchange medium (compatibility and pressure 
requirements). 
Paragraph 5.15.6.2., Gas flow prevention. 
 6. Applicable test procedures:  6.1. For parts of Class 1:  
Over pressure test Annex 15, para. 4 
 External leakage Annex 15, para. 5  High temperature Annex 15, para. 6  Low temperature Annex 15, para. 7  LPG compatibility Annex 15, para. 11 **
/ 
Corrosion resistance Annex 15, para. 12 * / 
 Resistance to dry heat Annex 15, para. 13 ** / 
 Ozone ageing Annex 15, para. 14 ** / 
Creep Annex 15, para. 15 ** / GSO STANDARD                                                                     GSO  /    
 
 128Temperature cycle Annex 15, para. 16 ** / 
 
6.2. For parts of Class 2 or 2A: 
 
Over pressure test Annex 15, para. 4 
 External leakage Annex 15, para. 5 
 High temperature Annex 15, para. 6 
 Low temperature Annex 15, para. 7 
 LPG compatibility Annex 15, para. 11 ** / 
Corrosion resistance Annex 15, para. 12 * / 
 
 
 
__________________  *
/ Only for metallic parts. 
 
**/ Only for non-metallic parts. 
  
 129Annex 14  
 
PROVISIONS REGARDING THE APPROVAL OF THE ELECTR ONIC CONTROL UNIT 
 
 1. The electronic control un it can be any device which controls the LPG demand of 
the engine and establishes the cut-off of the remotely-controlled service valve(s), 
cut-off valves and fuel pump of the LP G-system in case of a broken fuel supply 
pipe or/and in case of stalling of the engine. 
 
2. The switching off delay of the service cu t-off valves after st alling of the engine 
may not be more then 5 seconds. 
 3. The electronic control unit shall comply with relevant electromagnetic 
compatibility (EMC) requirements according to Regulation No. 10, 02 series of 
amendments or equivalent. 
 4. Electrical failure of the vehicle system may not lead to uncontrolled opening of any 
valve. 
 5. The output of the electronic control unit sh all be inactive when th e electric power is 
switched off or removed. 
 GSO STANDARD                                                                     GSO  /    
 
 130Annex 15  
TEST PROCEDURES 
1. Classification 
1.1. LPG components for use in vehicles shall be classified with regard to the 
maximum operating pressure and function, according to Chapter 2 of this 
Regulation.  
1.2 The classification of the components de termines the tests which have to be 
performed for type approval of the components or parts of the components. 
2. Applicable test procedures 
In Table 1 the applicable test proce dures dependent on the classification are 
shown. 
Table 1  
 
Test Class 1 Class 2(A) Class 3 Paragraph 
Overpressure x x x 4. 
External leakage x x x 5. 
High temperature x x x 6. 
Low temperature x x x 7. 
Seat leakage x  x 8. 
Endurance / Functional 
tests x  x 9. 
Operational test   x 10. 
LPG compatibility x x x 11. 
Corrosion resistance x x x 12. 
Resistance to dry heat x  x 13. 
Ozone ageing x  x 14. 
Creep x  x 15. 
Temperature cycle x  x 16. 
Compatibility with heat 
exchan ge flui d x   
 GSO STANDARD                                                                     GSO  /    
 
 1313. General requirements 
 3.1. Leakage tests shall have to be c onducted with pressuri zed gas like air or 
nitrogen. 
 3.2. Water or another fluid may be used  to obtain the required pressure for the 
hydrostatic strength test. 
 3.3. All test values shall indicate the type of test medium used, if applicable.  3.4. The test period for leakage- and hydrosta tic strength-tests sha ll be not less than 
1 minute. 
 
3.5. All tests shall be performe d at a room temperature of 20 ± 5 °C, unless 
otherwise stated. 
 
4. Overpressure test under hydraulic conditions  
A LPG containing component shall withst and without any visible evidence of 
rupture or permanent distor tion a hydraulic test pressu re which is determined 
by Table 1 (of 2.25 times the maximum cl assification pressu re) during minimal 
1 minute with the outlet of th e high pressure part plugged. 
 
The samples, previously subjected to the durability test of paragraph 9. are to be connected to a source of hydrostatic pressure.  A positive shut-off valve and a pressure gauge, having a pressure range  of not less than 1.5 times nor more 
than 2 times the test pressure, are to be installed in the hydrostatic pressure 
supply piping. 
 
Table 2 shows the classification pressure and the pressures to be used in the 
over-pressure test according to the classification: 
 
Table 2
 
  
Classification 
of component Classification 
pressure 
[kPa] Hydraulic test pressure 
for over-pressure test 
[kPa] 
Class 1, 3 3,000 6,750 
Class 2A 120 270 
Class 2 450 1,015 
 GSO STANDARD                                                                     GSO  /    
 
 1325. External leakage test 
 5.1. A component shall be free from leak age through stem or body seals or other 
joints, and shall not show evidence of  porosity in casting when tested as 
described in paragraph 5.3. at any aerostatic pressure between 0 and the 
pressure shown in Table 3.  The above pr escriptions are deemed to be satisfied, 
if the provisions of paragraph 5.4. are met. 
 5.2. The test shall be perfor med at the following conditions: 
 (i) at room temperature  (ii) at the minimum operating temperature  (iii) at the maximum operating temperature  
The maximum and minimum operating temper atures are given in the annexes. 
   5.3. During this test the equipment under test (EUT) will be c onnected to a source 
of aerostatic pressure (of 1.5 times the maximum pressure and in the case of a 
Class 3 component, 2.25 times the maximum classification pressure).  A positive shut-off valve and a pressure gauge having a pressure range of not less than 1.5 times nor more than 2 times the test pressure are to be installed in the pressure supply piping.  The pressure gauge is to be installed between the 
positive shut-off valve and the sample unde r test.  While under the applied test 
pressure, the sample should be submerge d in water to detect leakage or any 
other equivalent test method (flo w measurement or pressure drop). 
 
Table 3
:  The classification and leakage test pressures according to the 
classification: 
 
Classification 
of component Classification 
pressure 
[kPa] Test pressure 
for leakage test 
[kPa] 
Class 1 3,000 4,500 
Class 2A 120 180 
Class 2 450 675 
Class 3 3,000 6,750 
 
5.4. The external leakage must be lower than the requirements stated in the annexes 
or, if no requirements are mentioned, the external leakage shall be lower than 
15 cm3/hour with the outlet plugged, when submitted to a gas pressure equal to 
the leakage test pressure. 
 6. High temperature test 
 GSO STANDARD                                                                     GSO  /    
 
 134A LPG containing component sha ll not leak more than 15 cm3/hour with the 
outlet plugged when submitted to a gas pressure at maximum operating 
temperature, as indicated in the annexes, equal to the leakage test pressure 
(Table 3, paragraph 5.3.).  The compone nt shall be conditioned for at least 8 
hours at this temperature. 
 
7. Low temperature test 
 
A LPG containing component sha ll not leak more than 15 cm3/hour with the 
outlet plugged when submitted to a gas pressure, at the minimum operating 
temperature (-20 °C), equal to the leakag e test pressure (Table 3, paragraph 
5.3.).  The component shall be conditioned for at least 8 hours at this 
temperature. 
 8. Seat leakage test 
 
8.1. The following tests for seat leakage are to be conducted on samples of service 
valve or filling unit which have previously  been subjected to the external leak 
test of paragraph 5. above. 
 8.1.1. Seat leakage tests are conducted with the inlet of the sample  valve connected to 
a source of aerostatic pressure, the valve in the closed position, and with the 
outlet open.  A positive shut-off valve and a pressure gauge having a pressure range of not less than 1.5 times nor more than 2 times the test pressure are to be installed in the pressure supply piping.  The pressure gauge is to be installed 
between the positive shut-off valve and the sample under test.  While under the 
applied test pressure, observations for leakage are to be made with the open 
outlet submerged in water unless otherwise indicated. 
 
8.1.2. Conformance with paragraphs 8.2. to 8.8. below is to be determined by 
connecting a length of tubing to the valv e outlet.  The open end of this outlet 
tube is to be located within an inverted graduated cylinder which is calibrated in cubic centimetres.  The inverted cyli nder is to be closed by a water seal.  
The apparatus is to be adjusted so that: 
 
(1) the end of the outlet tube is located approximately 13 mm above the 
water level within the inverted graduated cylinder, and  
 GSO STANDARD                                                                     GSO  /    
 
 135(2) the water within and exterior to the graduated cylinder is at the same 
level.  With these adjustments made, the water level within the 
graduated cylinder is to be recorded .  With the valve in the closed 
position assumed as the result of normal operation, air or nitrogen at the specified test pressure is to be applied to the valve inlet for a test 
period of not less than 2 minutes.  During this time, the vertical 
position of the graduated cylinder is to be adjusted, if necessary, to maintain the same water level within and exterior to it. 
 
At the end of the test pe riod and with the water within and exterior to the 
graduated cylinder at the same level, th e level of water within the graduated 
cylinder is again recorded.  From the change of volume within the graduated 
cylinder, the leakage rate is to be  calculated according to the following 
formula:  
 
⎟
⎠⎞⎜
⎝⎛⋅⋅⋅=6.101273 60
1P
T tVVt  
 
 where:   V
1 = leakage rate, cubic centimetr es of air or nitrogen per hour. 
 V t = increase in volume within graduated cylinder during test. 
 t = time of test, minutes. 
 P = barometric pressure during test, in kPa.  T = ambient temperature during test, in K. 
 8.1.3. Instead of the method described above, leakage may be measured by a 
flowmeter installed on the inlet side of  the valve under test.  The flowmeter 
shall be capable of indi cating accurately, for the test fluid employed, the 
maximum leakage flow rates permitted. 
 8.2. The seat of a shut-off valve, when in  the closed position, shall be free from 
leakage at any aerostatic pressure between 0 to 3,000 kPa. 
 8.3. A non-return valve provided with a resilient seat, when in the closed position, 
shall not leak when subjected to any aerostatic pressure between 50 and 3,000 kPa. 
 8.4. A non-return valve provided with a me tal-to-metal seat, when in the closed 
position, shall not leak at  a rate exceeding 0.50 dm
3/hour when subjected to an 
inlet pressure up to the test pressure according to Table 3 in paragraph 5.3. 
 GSO STANDARD                                                                     GSO  /    
 
 1368.5. The seat of the upper n on-return valve used  in the assembly of a filling unit, 
when in the closed position, shall be  free from leakage at  any aerostatic 
pressure 
between 50 and 3,000 kPa. 
 8.6. The seat of a service coupling, when in the closed position, shall be free from 
leakage at any aerostatic pressure between 0 to 3,000 kPa. 
 8.7. The gas-tube pressure relief valve sh all not have internal  leakage up to 3,000 
kPa. 
 8.8. The pressure relief valve (discharge  valve) shall not have internal leakage 
up to 2,600 kPa. 
 9. Endurance test  9.1. A filling unit or service valve shall be  capable of conforming to the applicable 
leakage test requirements of paragraphs 5. and 8. above, after being subjected 
to a number of cycles of opening and cl osing as mentioned in the annexes. 
 9.2. A shut-off valve is to be tested wi th the valve outlet plugged.  The valve body 
filled with n-hexane, and the valve inlet subjected to a pressure of 3,000 kPa. 
 9.3. An endurance test is to be conducted at a rate not faster than 10 times per 
minute.  For a shut-off valve, the closing to rque is to be consistent with the size 
of handwheel, wrench, or other means employed to operate the valve. 
 9.4. The appropriate tests fo r external and seat leakage,  as described under external 
leakage test under paragraph 5. and seat leakage test under paragraph 8. are to 
be conducted immediately fo llowing the endurance test. 
 
9.5. Endurance for 80 per cent stop valve  9.5.1. The 80 per cent stop valve shall be ca pable to withstand 6,000 complete filling 
cycles to the maximum filling degree. 
 10. Operational tests  10.1. Operation test of the (g as-tube) pressure relief valve 
 10.1.1. In the case of pressure relief va lves, three samples of each size, design, and 
setting are to be used for start-to-dischar ge and resealing pressure tests.  This 
same set of three valves is to be used for flow capacity tests for other 
observations indicated in the following paragraphs. GSO STANDARD                                                                     GSO  /    
 
 137 
Not less than two successive start-to -discharge and resealing pressure 
observations are to be made  on each of the three test  valves under test No. 1 
and 3 of paragraphs 10.1.2. and 10.1.4. below. 
 
10.1.2. Start-to-discharge and resealing pressures of pressure  relief valves - test No. 1 
 10.1.2.1. Before being subjected to a flow cap acity test, the start-to-discharge pressure 
of each of three samples of a pressure re lief valve of a specific size, design, and 
setting shall be within +3 per cent of th e average of the pressures, but the start-
to-discharge pressure of any one of the three valves shall be not less than 95 
per cent, not more than 1 05 per cent, of the set pre ssure marked on the valve. 
 10.1.2.2. The resealing pressure of a pressu re relief valve before being subjected to a 
flow capacity test shall be not less than 50 per cent of the initially observed start-to-discharge pressure. 
 10.1.2.3. A pressure relief is to be connected  to an air or other aerostatic supply source 
capable of being maintained at a pressure  of at least 500 kPa effective pressure 
above the marked set pressure of the valve being tested.  A positive shut-off 
valve and a pressure gauge having a pre ssure range of not less than 1.5 times 
nor more than 2 times the test pressure ar e to be installed in  the pressure supply 
piping.  The pressure gauge is to be installed in the piping between the valve being tested and the positive shut-off valve.  Start-to-discharge and resealing pressure are to be observed through a water seal not over 100 mm in depth. 
 
10.1.2.4. After recording the star t-to-discharge pressure of the valve, the pressure is to 
be increased sufficiently above the star t-to-discharge pressure to ensure 
unseating of the valve.  The shut-off valve is then to be closed tightly and the 
water seal, as well as the pressure ga uge, are to be obser ved closely.  The 
pressure at which bubbles through the water seal cease is to be  recorded as the 
resealing pressure of the valve. 
 
10.1.3. Flow capacity of pressure  relief valves - test No. 2 
 10.1.3.1. The flow capacity of each of thre e samples of a pressure relief valve of a 
specific size, design, and se tting shall fall within a ra nge of 10 per cent of the 
highest observed capacity. 
 GSO STANDARD                                                                     GSO  /    
 
 13810.1.3.2. During flow capacity tests on each  valve, there shall be no evidence of 
chattering or other abnormal operating condition. 
 
10.1.3.3. The blow-down pressure of each valv e shall be not less than 65 per cent of the 
initially recorded start-to-discharge pressure. 
 10.1.3.4. A flow capacity test on a pressure  relief valve is to be conducted at a flow 
rating pressure of 120 per cent of the maximum set pressure. 
 10.1.3.5. A flow capacity test on a pressure re lief valve is to be c onducted by utilizing a 
properly designed and calibrated orifi ce flowmeter of the flange type 
connected to a source of air supply of adequate capacity and pressure.  
Modifications of the flowmeter from that  described herein, and an aerostatic 
flow medium other than air, may be us ed provided the end results are the same. 
 10.1.3.6. The flowmeter is to be arranged with sufficiently long lengths of pipe both 
preceding and following the orifice, or other arrangements including straightening vanes, to assure no dist urbance at the orifi ce place for the ratios 
of orifice to pipe diam eters to be employed. 
 
Flanges between which the orifice plat e is located and clamped are to be 
provided with pressure take-off line s connected to a manometer.  This 
instrument indicates the pressure diffe rential across the orifice plate and the 
reading is used in the flow calculation.  A calibrated pressure gauge is to be 
installed in that portion of the meter pipe  downstream of the orifice plate.  This 
gauge indicates the flow pressure and th e reading is also used in the flow 
calculation. 
 
10.1.3.7. A temperature-indicating instrument  is to be connected to the meter pipe 
downstream of the orifice plate to indicat e the temperature of the air flowing to 
the safety valve.  The reading of this instrument is to be integrated in the calculation to correct the temperature of the air flow to a 15 °C base 
temperature.  A barometer is to be available for indicating the prevailing 
atmospheric pressure. 
 
The reading of the barometer is to be added to the indicated air-flow gauge 
pressure.  This absolute pressure is si milarly to be integrated in the flow 
calculation.  The air pressure to the fl owmeter is to be controlled by a suitable 
valve installed in the air-supply piping ah ead of the flowmeter.  The pressure 
relief valve under test is to be connected  to the discharge end of the flowmeter. 
 10.1.3.8. After all preparations for flow capac ity tests have been made, the valve in the 
air-supply line is to be opened slowly and the pressure to the valve under test is to be increased to the appropriate flow rating pressure.  During this interval, the GSO STANDARD                                                                     GSO  /    
 
 139pressure at which the valve "pops" ope n is to be recorded as the popping 
pressure. 
 
10.1.3.9. The predetermined flow rating pressure  is to be maintained constant for a brief 
interval until the readings of the instru ments become stabilized.  Readings of 
the flow pressure gauge, pressure diffe rential manometer, and the flowing air 
temperature indicator are to be recorded  simultaneously.  The pressure is then 
to be decreased until there is no further discharge from the valve. 
 
The pressure at which this occurs is to  be recorded as the blow-down pressure 
of the valve. 
 10.1.3.10. From the recorded data and the known  orifice coefficient of the flowmeter, the 
air-flow capacity of the pressure relief valv e tested is to be calculated using the 
following formula: 
 
601.0 ph FFQt b ⋅⋅⋅⋅=  
  where:  
Q = Flow capacity of pressure relief valve - in m
3/min. of air at 100 kPa 
absolute and 15 °C. 
 
Fb = Basic orifice factor of flowme ter at 100 kPa absolute and 15 °C. 
 
Ft = Flowing air temperature factor to  convert recorded temperature to 
base of 15 °C. 
 
h = Differential pressure across orifice of meter in kPa. 
 
p = Flowing air pressure to pressure  relief valve - in kPa absolute 
(recorded gauge pressure plus r ecorded barometric pressure). 
 
60 = Denominator to convert equation from m3/hour to m3/min. 
 
10.1.3.11. The average flow capacity of the th ree pressure relief valves rounded off to the 
nearest five units is to be taken as the flow capacity of the valve of that specific 
size, design, and setting. 
 
10.1.4. Recheck start-to-discharge and resea ling pressures of pressu re-relief-valves test 
No. 3 
 10.1.4.1. Subsequent to flow capacity tests, th e start-to-discharge pressure of a pressure GSO STANDARD                                                                     GSO  /    
 
 140relief valve shall be not less than 85 pe r cent, and the resealing pressure shall 
be not less than 80 per cent of the in itial start-to-discharge and resealing 
pressures recorded under test No. 1 of paragraph 10.1.2. 
 
10.1.4.2. These tests are to be conducted ap proximately 1 hour afte r the flow capacity 
test, and the test procedure is to be th e same as described under test No. 1 of 
paragraph 10.1.2. 
 10.2. Operation test excess flow valve  10.2.1. An excess flow valve shall operate at not more than 10 per cent above, nor less 
than 20 per cent below the rated closing flow capacity specified by the manufacturer, and shall close automatically  at a pressure differential across the 
valve of not more than 100 kPa durin g the operation tests described below. 
 10.2.2. Three samples of each size and style of valve are to be subjected to these tests.  
A valve intended for use only with liquid is  to be tested with water, otherwise 
the tests are to be made both with air a nd with water.  Except as indicated in 
paragraph 10.2.3., separate tests are to be run with each sample installed in vertical, horizontal and inverted positions.  The tests with air to be made without piping or other rest riction connected to the ou tlet of the tests sample. 
 10.2.3. A valve intended for installation in on e position only may be tested only in that 
position. 
 10.2.4. The test with air is to be c onducted by utilizing a properly designed and 
calibrated orifice flowmeter of the flange  type, connected to a source of air 
supply of adequate capacity and pressure. 
 
10.2.5. The test sample is to be connected to the outlet of the flowmeter.  A 
manometer or calibrated pressure-gauge reading in increments of not more 
than 3 kPa is to be installed on the upstr eam side of the test sample to indicate 
the closing pressure. 
 10.2.6. The test is conducted by slowly increasing the flow of air through the 
flowmeter until the check valve closes.  At the instant of closing, the pressure differential across the flowmeter orifice and the closing pressure indicated by 
the gauge are to be recorded.  The rate of flow at closing is then to be calculated. 
 10.2.7. Other types of flowmeters and a gas, other than air, may be used. 
 10.2.8. The test with water is to be conduc ted using a liquid flow meter (or equivalent) 
installed in a piping system having suffi cient pressure to provide the required GSO STANDARD                                                                     GSO  /    
 
 141flow.  The system is to include an inlet piezometer or pipe at least one pipe size 
larger than the valve to be tested, with a flow control valve connected between 
the flowmeter and piezometer.  A hose or  hydrostatic relief va lve, or both, may 
be used to reduce the effect of the pressure shock when the excess flow valve closes. 
 10.2.9. The test sample is to be connected  to the outlet end of the piezometer.  A 
manometer or calibrated pressure gauge of the retard type, which will permit 
readings in the range of 0 to 1,440 kPa is  to be connected to  a pressure take-off 
on the upstream side of the test sample to indicate the closing pressure.  The connection is to be made using a lengt h of rubber hose between the pressure 
gauge and the pressure take-off, with a valve installed at the gauge inlet to 
permit bleeding air from the system. 
 10.2.10. Prior to the test, the flow control va lve is to be opened slightly, with the bleed 
valve at the pressure gauge open, to e liminate air from the system.  The bleed 
valve is then to be closed and the te st is conducted by slowly increasing the 
flow until the check valve closes.  During the test the pressure gauge is to be 
positioned at the same level as the test sample.  At the instant of closing, the rate of flow and closing pressure are to be recorded.  When the excess flow 
valve is at cut-off position, the leakag e or by-pass rate of flow is to be 
recorded. 
 10.2.11. An excess flow valve used in th e assembly of a filling unit shall close 
automatically at a pressure differential of  not more than 138 kPa when tested as 
described below. 
 10.2.12. Three samples of each size of valve are to be subjected to these tests.  The tests 
are to be made with air, and separate tests are to be run with each sample 
mounted vertically and horizontally.  The tests are to be conducted as described 
in paragraphs 10.2.4. to 10.2.7., with a filling unit hose coupling connected to the test sample and with the upper non-return valve he ld in the open position. 
 10.3. Charging-speed-test  10.3.1. Testing of the good function of the de vice limiting the filling degree of the 
container has to be performed by filling speeds of 20, 50 and 80 l/min or to the maximum flow rate under an ups tream pressure of 700 kPa abs. 
 10.4. Endurance-test for the filling limiter  
The device limiting the filling degree of the container shall be capable of withstanding 6,000 complete filling cycl es to the maximum filling degree. 
 GSO STANDARD                                                                     GSO  /    
 
 14210.4.1. Scope 
 
Any device limiting the filling degree of th e container and operating by a float, 
after having been subjected to  the tests verifying that: 
 
It limits the degree of filling of the c ontainer to 80 per cent or less of its 
capacity; 
 
It does not allow - at the cut-off position - any filling of the container at a rate 
exceeding 0.5 litre/minute, 
 
Shall be subjected to one of the test pr ocedures laid down in paragraph 10.5.5. 
or 10.5.6. below to ensure that the devi ce is constructed to withstand expected 
dynamic vibrational stresses and to ensure  that performance degradations or 
malfunctions will not be produced by the service vibration environment. 
 10.5. Vibration test procedure  10.5.1. Equipment and mounting techniques  
The test item shall be attached to the vibration equipment by its normal 
mounting means, either direc tly to the vibration exciter or transition table, or 
by means of a rigid fixture capable of transmitting the specified vibration conditions.  Equipment used to measure an d/or record the acceleration level or 
amplitude level and the frequency shall ha ve an accuracy of at least 10 per cent 
of the measured value. 
 10.5.2. Choice of procedure 
 
At the choice of the authority granting type-approval the tests shall be performed according to either procedure A described in paragraph 10.5.5. or 
procedure B described in paragraph 10.5.6. 
 10.5.3. General  
The following tests shall be carried out along each of the three orthogonal axes 
of the test item. 
 10.5.4. Procedure A  10.5.4.1. Resonance search  
Resonant frequencies of the filling limiter shall be determined by varying the frequency of applied vibration slowly through the specified range at reduced GSO STANDARD                                                                     GSO  /    
 
 143test levels but with sufficient amplit ude to excite the item.  Sinusoidal 
resonance search may be performed us ing the test level and cycling time 
specified for the cycling test, provided the resonance search time is included in 
the required cycling test ti me of paragraph 10.5.5.3. 
 
10.5.4.2. Resonance dwell test  
The test item shall be vibrated for 30 minutes along each axis at the most 
severe resonant frequencies determined in paragraph 10.5.5.1.  The test level 
shall be 1.5 g (14.7 m/sec
2). If more than four signi ficant resonant frequencies 
are found for any one axis, the four most severe resonant frequencies shall be 
chosen for this test.  If a change in the resonant frequency occurs during the 
test, its time of occurren ce shall be recorded and immediately the frequency 
shall be adjusted to maintain the peak resonance condition.  The final resonant 
frequency shall be recorded.  The total dwell test time shall be included in the 
required cycling test time of paragraph 10.5.5.3. 
 
10.5.4.3. Sinusoidal cycling test  
The test item shall be sinus oidally vibrated for three hours along each of its 
orthogonal axes in accordance with: 
 
an acceleration level of 1.5 g. (14.7 m/sec
2), 
 
a frequency range of 5 to 200 Hz, 
 
a sweep time of 12 minutes. 
 
The frequency of applied vibration sh all be swept over the specified range 
logarithmically. 
 
The specified sweep time is that of an ascending plus a descending sweep. 
 10.5.5. Procedure B  10.5.5.1. The test shall be performed on a sinusoidal vibrating bench, at a constant 
acceleration of 1.5 g and at frequencie s ranging between 5 and 200 Hz.  The 
test shall last for 5 hours for each of th e axes specified in paragraph 10.5.4.  
The frequency band 5-200 Hz shall be covered in each of the two senses in 15 minutes. 
 10.5.5.2. Alternatively, in case the test  is not conducted by utilizing a constant 
acceleration bench, the frequency band from 5 to 200 Hz has to be subdivided in 11 semi-octave bands, each of them covered by a constant amplitude, so that GSO STANDARD                                                                     GSO  /    
 
 144the theoretical acceleration is include d between 1 and 2 g (g = 9.8 m/sec2). 
 
 Vibration amplitudes for each band are as follows: 
 
Amplitude 
in mm 
(crest value) Frequency in Hz 
(for acceleration = 1g) Frequency in Hz 
(for acceleration = 2g) 
10 
5 
2.50 1.25 
0.60 0.30 0.15 
0.08 
0.04 0.02 0.01 5 
7 
10 
14 
20 29 41 
57 
79 
111 157 7 
10 
14 
20 
29 41 57 
79 
111 
157 222 
  
Each band shall be covered in both directions in 2 minutes, 30 minutes totally 
for each band. 
 10.5.6. Specification  
After having been subjected to one of th e vibration test procedures described 
above the device shall show no mechanic al failures and is deemed to conform 
to the vibration test requirements only in the case the values of its characteristic parameters: 
 
filling degree at the cut-off position,  filling rate allowed at the cut-off position, 
 
do not exceed the prescribed limits and are not exceeding by more than 10 per cent the values preceding the vibration test procedure. 
 11. LPG compatibility tests for synthetic materials  11.1. A synthetic part in contact with LP G-liquid shall not show excessive volume 
change or loss of weight. 
 GSO STANDARD                                                                     GSO  /    
 
 146Resistance to n-pentane according to ISO 1817 with the following conditions: 
 
(i) medium: n-pentane 
 (ii) temperature: 23 °C (tolerance acc. to ISO 1817) 
 (iii) immersion period: 72 hours 
 11.2. Requirements:    maximum change in volume 20 per cent 
After storage in air with a temperatur e of 40 °C for a period of 48 hours the 
mass compared to the original value ma y not decrease more than 5 per cent. 
 12. Corrosion resistance  12.1. A metal LPG containing component shall comply with the leakage tests 
mentioned in 4, 5, 6 and 7 and after having been submitted to 144 hours salt spray test according to ISO 9227, with all connections closed. 
 
or an optional test: 
 12.1.1. A metal LPG containing component shall comply with the leakage tests 
mentioned in 4, 5, 6 and 7 and after having been submitted to a salt spray test according to IEC 68-2-52 Kb: Salt Spray Fog Test. 
  Test procedure:
  
 
Before the test the component shall be cleaned according to the instructions of 
the manufacturer.  All the connections shall be closed off.  The component 
shall not be operated during the test. 
 
Subsequently the component shall be submitted during 2 hours to spraying with a solution of salt, containing 5 per cent NaCl (mass per cent) with less than 0.3 per cent contamination and 95 per cent distilled or demineralised water, at a temperature of 20 °C.  After the spraying the compone nt is stored at 
temperature of 40 °C and 90-95 per cent relative humidity for 168 hours.  This 
sequence shall be repeated 4 times. 
 
After the test the component shall be cl eaned and dried during 1 hour at 55 °C.  
The component shall now be conditioned to reference conditions during 4 hours, before submitting it to further testing. 
 12.2. A copper or brass LPG containing component shall comply with the leakage 
tests mentioned in 4, 5, 6 and 7 and after having been submitted to 24 hours immersion in Ammonia according to IS O 6957 with all connections closed. 
 GSO STANDARD                                                                     GSO  /    
 
 14713. Resistance to dry-heat 
 
The test has to be done in compliance w ith ISO 188.  The test piece has to be 
exposed to air at a temperature equal to the maximum operating temperature for 168 hours. 
 
The allowable change in tensile strength should not exceed +25 per cent. 
 
The allowable change in ultimate el ongation shall not exceed the following 
values: 
 
Maximum increase 10 per cent Maximum decrease 30 per cent 
 14. Ozone ageing  14.1. The test has to be in compliance with ISO 1431/1. 
 The test piece, which has to be stre ssed to 20 per cent elongation shall be 
exposed to air at 40 °C with an ozone concentration of 50 parts per hundred 
million during 72 hours. 
 14.2. No cracking of the test piece is allowed.  15. Creep  
A non metallic part containing liquid LPG shall comply with the leakage tests 
mentioned in paragraphs 5., 6. and 7. after having been submitted to a hydraulic pressure of 2.25 times th e maximum operating pressure at a 
temperature of 120 °C during minimal 96 hours.  Water or any other suitable 
hydraulic fluid may be used as a test medium. 
 16. Temperature cycle test  
A non-metallic part containing liquid LPG shall comply with the leakage tests 
mentioned in paragraphs 5., 6. and 7. after having been submitted to a 96 hours temperature cycle from the minimum operating temperature up to the maximum operating temperature with  a cycle time of 120 minutes, under 
maximum working pressure. 
 GSO STANDARD                                                                     GSO  /    
 
 14817. Compatibility with heat exch ange fluids of non-metallic parts 
 
17.1. Test samples shall be submerged in heat exchange medium for 168 hours at 
90 °C; then they shall be dried for 48 hours at a temperature of 40 °C.  The composition of the heat exchange medium used for the test is water/ethylene-
glycol fluid of 50%/50%. 
 17.2. The test is deemed to be satisfactory if the change in volume is less than 
20 per cent, the change in mass is less than 5 per cent, the change in tensile strength is less than –25 per cent and the change in  elongation at break is 
within –30 per cent and +10 per cent. 
 GSO STANDARD                                                                     GSO  /    
 
 149Annex 16  
 
PROVISIONS REGARDING LPG ID ENTIFICATION MARK FOR M 2 AND M 3 
CATEGORY VEHICLES 
 
 
   
 
      
 
         
 
  The sign consists of a sticker wh ich must be weather resistant. 
 
The colour and dimensions of the sticke r must fulfil the following requirements: 
  Colours:   Background   : green   Border     : white or white reflecting   Letters     : white or white reflecting    Dimensions   Border width   : 4 - 6 mm 
  Character height  : ≥ 25 mm 
   Character thickness : ≥  4 mm 
  Sticker width   : 110 - 150 mm 
  Sticker height   :  80 - 110 mm  GSO STANDARD                                                                     GSO  /    
 
 150 The word "LPG" must be centred in the middle of the sticker. 
 GSO STANDARD                                                                     GSO  /    
 
 151Annex 17  
 
PROVISIONS REGARDING IDENTIFICATI ON MARK FOR SERVICE COUPLING 
 
 
 
 
 
The sign consists of a sticker wh ich must be weather resistant. 
 
The colour and dimensions of the sticke r must fulfil the following requirements: 
 
Colours: 
Background   : red 
  Letters     : white or white reflecting    Dimensions 
  Character height  : ≥ 5 mm 
  Character thickness : ≥ 1 mm 
  Sticker width   : 70 - 90 mm 
  Sticker height   : 20 - 30 mm  
 The text "FOR SERVICE PURPOSES ONLY " must be centred in the middle of 
the sticker.  
         
    GSO STANDARD                                                                     GSO  /    
 
 153Annex 18  
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 155 
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 156
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 157 
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 158
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 159 
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 GSO STANDARD                                                                     GSO  /    
 
 161 
 
 
  
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