DRAFT UGANDA STANDARD  
  DUS 2159 -4 
First  Edition  
2019 -mm-dd 
 
 
 Reference number  
DUS 2159 -4: 2019  
© UNBS 2019   
  
Hydraulic fluid  — Performance Classifications  — Part 4: 
Specifications for hydraulic fluids in categories HETG, HEPG, 
HEES and HEPR  DUS 2159 -4:2019  
© UNBS 2019  – All rights reserved  ii 
 Compliance with this standard does not, of itself confer immunity from legal obligations  
A Uganda Standard does not purpor t to include all necessary provisions of a contract. Users are 
responsible for its correct application  
© UNBS yyyy  
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilised in any 
form or by any means, elec tronic or mechanical, including photocopying and microfilm, without prior written 
permission from UNBS.  
Requests for permission to reproduce this document should be addressed to  
The Executive Director  
Uganda National Bureau of Standards  
P.O. Box 6329  
Kampa la 
Uganda  
Tel: +256 41 4 333 2 50/1/2/3  
Fax: +256 41 4 286 123  
E-mail: info@unbs.go.ug  
Web: www.unbs.go.ug  DUS 2159 -4:2019  
© UNBS 2019  – All rights reserved  iii 
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ ............................  iv 
1 Scope  ................................ ................................ ................................ ................................ ......................  7 
2 Normative references  ................................ ................................ ................................ ............................  7 
3 Terms and defi nitions  ................................ ................................ ................................ ...........................  8 
4 Viscosity classification  ................................ ................................ ................................ .........................  8 
5 Requirements  ................................ ................................ ................................ ................................ .........  9 
5.1 General re quirements  ................................ ................................ ................................ ...........................  9 
5.2 Performance categories  ................................ ................................ ................................ .......................  9 
5.3 Environmental behaviour requirements  ................................ ................................ .............................  9 
5.4 Specific requirements  ................................ ................................ ................................ .........................  10 
6 Packaging  ................................ ................................ ................................ ................................ .............  10 
7 Labelling  ................................ ................................ ................................ ................................ ...............  10 
8 Sampling  ................................ ................................ ................................ ................................ ..............  10 
Annex  A (normative)  Laboratory/bench test requirements  ................................ ................................ ........  12 
Annex B (informative)  Guidelines for changing fluids f rom mineral -based oils to environmentally 
acceptable fluids  ................................ ................................ ................................ ................................ ... 1 
 
. DUS 2159 -4:2019  
© UNBS 2019  – All rights reserved  iv 
 Foreword  
Uganda National Bureau of Standards (UNBS) is a parastatal under the Ministry of Trade , Industry and 
Cooperatives established under Cap 327 , of the Law s of Uganda , as amended .  UNBS is mandated to co -
ordinate the elaboration of standards and is  
(a) a member of International Organisation for Standardisation (ISO) and  
(b) a contact point for the WHO/FAO Codex Alimentarius Commission on Food Standards, and  
(c) the N ational Enquiry Point on TBT  Agreement  of the World Trade Organisation (WTO).  
The work of preparing Uganda Standards is carried out through Technical Committees. A Technical 
Committee is established to deliberate on standards in a given field or area and c onsists of key stakeholders 
including government, academia, consumer groups, private sector and other interested parties.  
Draft Uganda Standards adopted by the Technical Committee are widely circulated to stakeholders and the 
general public for comments. The committee reviews the comments before recommending the draft standards 
for approval and declaration as Uganda Standards by the National Standards Council.  
The committee responsible for this document is Technical Committee UNBS /TC 16, [name of committee ], 
Subcommittee SC 1, Petroleum  and Petrochemical . 
DUS 2159  consists of the following parts, under the general title Hydraulic Lubricating Fluid  — Performance 
Classifications :  
  Part 1 : General  
  Part 2: Specifications for categories HH, HL, HM, HV and HG  
  Part 3: Specifications for hydraulic fluids in categories HFAE, HFAS, HFB, HFC, HFDR and HFDU . 
  Part 4 Specifications for hydraulic fluids in categories HETG, HEPG, HEES and HEPR . 
 DUS 2159 -4:2019  
© UNBS 2019  – All rights reserved  v 
 Introduction  
This draft Uganda Standard gives specifications for envir onmentally acceptable hydraulic fluids (HE). These 
fluids are readily biodegradable and have a low eco ‑toxicity. They are designed to minimize the impact upon 
the environment in the event of a leak or spill  and to provide guidance for suppliers and users o f 
environmentally acceptable hydraulic fluids and for the direction of original equipment manufacturers of 
hydraulic systems.  
 DUS 2159 -4:2019  
© UNBS 2019  – All rights reserved  vii 
 Hydraulic fluid  — Performance Classifications  — Part 4: 
Specifications for hydraulic fluids in categories HETG, HEPG, HEES 
and H EPR 
1 Scope   
This draft Uganda Standard  specifies performance requirements, sampling and test methods for environmentally 
acceptable hydraulic fluids and is intended for hydraulic systems, particularly hydraulic fluid power systems. This draft 
Uganda Stand ard stipulates the requirements for environmentally acceptable hydraulic fluids at the time of delivery.  
2 Normative references   
The following referenced documents referred to in the text in such a way that some or all of their content constitutes 
requirem ents of this document. For dated references, only the edition cited applies. For undated references, the latest 
edition of the referenced document (including any amendments) applies.  
US ISO 2049, Petroleum products — Determination of colour (ASTM scale)  
US ISO 2160, Petroleum products — Corrosiveness to copper — Copper strip test  
US ISO 2592, Determination of flash and fire points — Cleveland open cup method  
US ISO 3016, Petroleum products — Determination of pour point  
US ISO 3104, Petroleum products — Transparent and opaque liquids — Determination of kinematic viscosity and 
calculation of dynamic viscosity  
US ISO 3170, Petroleum liquids — Manual sampling  
DUS ISO 3448, Industrial liquid lubricants — ISO viscosity classification  
US ISO 3675, Crude petroleum  and liquid petroleum products — Laboratory determination of density — Hydrometer 
method  
DUS ISO 4263 -1, Petroleum and related products — Determination of the ageing behaviour of inhibited oils and fluids — 
TOST test — Part 1: Procedure for mineral oils  
DUS ISO 4263 -3, Petroleum and related products — Determination of the ageing behaviour of inhibited oils and fluids 
using the TOST test — Part 3: Anhydrous procedure for synthetic hydraulic fluids  
DUS ISO 4406, Hydraulic fluid power — Fluids — Method for cod ing the level of contamination by solid particles  
DUS ISO 6072, Rubber — Compatibility between hydraulic fluids and standard elastomeric materials  
US ISO 6247, Petroleum products — Determination of foaming characteristics of lubricating oils  
US ISO 6296, P etroleum products — Determination of water — Potentiometric Karl Fischer titration method  DUS 2159 -4:2019  
© UNBS 2019  – All rights reserved  viii 
 DUS ISO 6341, Water quality — Determination of the inhibition of the mobility of Daphnia magna Straus (Cladocera, 
Crustacea) — Acute toxicity test  
DUS ISO 7120, Petro leum products and lubricants — Petroleum oils and other fluids — Determination of rust - 
preventing characteristics in the presence of water  
DUS ISO 7346 -2, Water quality — Determination of the acute lethal toxicity of substances to a freshwater fish 
[Brach ydanio rerio Hamilton -Buchanan (Teleostei, Cyprinidae)] — Part 2: Semi -static method  
DUS ISO 8192, Water quality — Test for inhibition of oxygen consumption by activated sludge for carbonaceous and 
ammonium oxidation  
DUS ISO 9120, Petroleum and related pro ducts — Determination of air -release properties of steam turbine and other 
oils — Impinger method  
DUS ISO 9439, Water quality — Evaluation of ultimate aerobic biodegradability of organic compounds in aqueous 
medium — Carbon dioxide evolution test  
DUS ISO 1 0634, Water quality — Guidance for the preparation and treatment of poorly water -soluble organic 
compounds for the subsequent evaluation of their biodegradability in an aqueous medium  
DUS  ISO 11500, Hydraulic fluid power — Determination of the particulate contamination level of a liquid sample by 
automatic particle counting using the light -extinction principle  
US ISO 12937, Petroleum products — Determination of water — Coulometric Karl Fischer titration method  
DUS  ISO 14593, Water quality — Evaluation of ul timate aerobic biodegradability of organic compounds in aqueous 
medium — Method by analysis of inorganic carbon in sealed vessels (CO2 headspace test)  
DUS  ISO 14635 -1, Gears — FZG test procedures — Part 1: FZG test method A/8,3/90 for relative scuffing loa d- 
carrying capacity of oils  
US ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories  
DUS  ISO 20763, Petroleum and related products — Determination of anti -wear properties of hydraulic fluids — Vane 
pump method  
3 Terms and definitions   
No terms and definitions are listed in this document.  
ISO and IEC maintain terminological databases f or use in standardization at the following addresses:  
— ISO Online browsing platform: available at http://www.iso.org/obp  
4 Viscosity  classification  
The viscosity of the hydraulic fluid shall be classified basing on the ISO viscosity classification, as pe r designations 
indicated in US ISO 3448.  DUS 2159 -4:2019  
© UNBS 2019  – All rights reserved  ix 
 5 Requirements  
5.1 General requirements  
The Hydraulic fluid shall consist of acceptable petroleum products, or of acceptable synthetically prepared products, or 
of a combination of these two types of products, compo unded in all cases, with such functional additives, for example, 
detergents, dispersants, oxidation inhibitors and corrosion inhibitors as are necessary to enable it to comply with the 
other requirements of this standard.  
For the purpose of this Draft Ugan da Standard, hydraulic fluids shall be triglycerides, polyglycols, synthetic esters, 
polyalphaolefins and related hydrocarbon products.  
The appearance of the delivered oils shall be clear and bright and free of any visible particulate matter when viewed 
under normal visible light at ambient temperature. The cleanliness level shall be expressed according to ISO 4406 and 
ISO 11500.  
The precision (repeatability and reproducibility) of the test methods in this draft Uganda  Standard and the interpretation 
of the  results shall be in accordance with ISO 4259, which shall be consulted in instances of uncertainty or dispute.  
The Hydraulic fluid shall remain clear and homogeneous, and shall show no evidence of separation of components and 
no evidence of colour change.  
The Hydraulic fluid shall be compatible with other fluids of the same viscosity grade that comply with the requirements of 
this standard.  
5.2 Performance categories  
Candidate Hydraulic fluid shall be formulated such that their performance requirements mee t one of the performance 
categ ories HETG, HEPG, HEES and HEPR as specified in DUS 2159 -3:2019 . 
The minimum content of base fluid for each category shall not be less than 70 % (m/m).  
NOTE: The consumer shall refer to the owner’s or operator’s manual for rec ommended category of hydraulic fluid to be used in a 
specific hydraulic system  
5.3 Environmental behaviour requirements  
The environmental behaviour specifications for categories HETG, HEPG, HEES and HEPR are given in  Table 1.  
The biodegradability and aquat ic toxicity tests shall be performed in a laboratory operating in accordance with  US 
ISO/IEC 17025 or according to Good Laboratory Practice (GLP).  
Table 1 — Environmental behavior  requirements for categories HETG, HEPG, HEES and HEPR  
Characteristic of test  Unit Requirement  Test method  
Biodegradability, 28 days, min.  % 60 ISO 14593 or ISO 9439  
Toxicitya    
Acute fish toxicity, 96 h, LC50, min.  mg/l 100 ISO 7346 -2 
Acute Daphnia toxicity, 48 h, EC50, min.  mg/l 100 DUS ISO 6341  
Bacterial inhibition, 3 h, EC50, min.  mg/l 100 ISO 8192  DUS 2159 -4:2019  
© UNBS 2019  – All rights reserved  x 
 a Water‑soluble fluids shall be tested according to the test method cited. Fluids with low water solubility shall be tested using 
water‑accommodated fractions, prepared according to ISO 10634.  
 
5.4 Specific  requirements  
In addition to meeting the requirements gi ven in Clause 5.1, 5.2 & 5.3  above, hydraulic fluid shall comply with specific 
requirements  provided hereafter in Annex A . 
6 Packaging  
The condition of the drums or smaller containers and the bulk tankers in to which the hydraulic fluid is filled, shall hav e no 
detrimental effect on the quality of the hydraulic fluid during normal transportation and storage. Only containers of the 
same size filled with hydraulic fluid of the same batch identification shall be packed together in a carton. Prior to use, 
contai ners shall be firmly secured with a tamper -proof seal.  
7 Labelling  
Each container and each carton (if present) shall be legibly and indelibly marked with the following information in English 
language.  
a) product name and application;  
b) name and address of the manufacturer and registered trade mark if any and/or distributor’s name;  
c) category of fluid according to ISO classification;   
d) ISO viscosity grade;  
e) net content;  
f) origin of the product/Made in; and  
g) date of production and the batch number  
h) expiry date  
i) Caution  and warnings  
 
8 Sampling  
Sampling of hydraulic fluids for the purpose of this Draft Uganda  Standard shall be carried out in accordance with the 
appropriate procedure described in ISO 3170.  
 
 
 DUS 2159 -4:2019  
© UNBS 2019  – All rights reserved  xi 
  
 
 DUS 2159 -4:2019  
© UNBS 2019  – All rights reserved  xii 
 Annex  A 
(normative)  
 
Laboratory/bench test requirements  
Table 1  — Specifications for type HETG hydraulic fluids, triglycerides  
 
Characteristic of test   
Unit  
Requirement  Test method or 
applicable 
standard  
Viscosity grade   22 32 46 68 ISO 3448  
Flash point  
Cleveland open cup, (min). °C 165 175 185 195 ISO 2592  
Kinematic viscosity        
at 0 °C, (max). mm2/s  300 420 780 1,400 ISO 3104  
at 40 °C, . mm2/s  19,8 - 24,2 28,8 - 35,2 41,4 - 50,6 61,2 - 74,8  
at 100 °C, min.  mm2/s  4.1 5.0 6.1 7.8  
Water content  mg/kg  1 000  1 000  1 000  1 000  ISO 12937  
ISO 6296  
Copper co rrosion, 100 °C  
3 h, (max). rating  2 2 2 2 ISO 2160  
Rust prevention, procedure A, 
24 h — Pass  Pass  Pass  Pass  ISO 7120  
Foam        
at 24 °C, (max).. (Sequence I)  
at 93 °C, (max). (Sequence II)  ml 
ml 150/0  
80/0 150/0  
80/0 150/0  
80/0 150/0  
80/0 ISO 6247  
at 24 °C, (max).. (Sequence III)  ml 150/0  150/0  150/0  150/0   
Air release, 50 °C, (max).. min 7 7 10 10 ISO 9120  
Elastomer compatibilitya       
after 1 000 h at given tem -       
perature        
NBR 1  °C 60 80 80 80  
HNBR  °C 60 80 80 80  
FKM 2  °C 60 80 80 80  
AUb °C 60 80 80 80  
Change in shore A hardness, 
(max).  grade  ±10 ±10 ±10 ±10 ISO 6072  
Change in volume, (max).  % -3 to +10  -3 to +10  -3 to +10  -3 to +10   DUS 2159 -4:2019  
© UNBS 2019  – All rights reserved  xiii 
 Change in elongation, (max). . % 30 30 30 30  
Change in tensile strength, 
(max). . % 30 30 30 30  
Oxidation stability:        
Increase in viscosity at 40 °C, 
(max). . % 20 20 20 20 ISO 4263 -3 
 
Load‑carrying properties,  
FZG A/8,3/90, (min). stage  —c 10 10 10 ISO 14635 -1 
Vane pump, Procedure Ad       
Ring, (max).  mg 120 120 120 120 ISO 20763  
Vane, (max). . mg 30 30 30 30  
a The requirements for two of the listed elastomer types shall be met. The values are minimum requirements  for standard reference 
elastomers. The elastomers are suitable for guidance and selection of the correct  sealing material. Other materials and/or test conditions 
may be agreed between supplier and customer. The  applicability to the behaviour of the elastomer used in practice should be 
considered.  
b No hydrolytic stabilized elastomer exists for AU. Manufacturers pr oduce stabilized AU materials for practical  applications. It is 
recommended that users clarify this point with the elastomer manufacturer.  
c Not applicable to viscosity grade 22.  
d There are currently no precision data for the method when non -Eaton/Vickers  test cartridges (e.g. Conestog USA, Inc. and Tokimec) 
are used. Consequently, no absolute mass loss limits can be stipulated until the  precision of V104C pump cartridges from the new 
supplier has been determined. In the interim, the limits previously  established for Eaton/Vickers cartridges may be used for guidance. It 
should be noted that ISO 20763  supersedes BS 2000: Part 281, IP 281 and DIN 51389. For fluids evaluated under the aforementioned 
methods,  the test data are considered to remain valid and no re-testing against ISO 20763 is required.  
 
Table 2  — Specifications for type HEPG hydraulic fluids, polyglycols  
 
Characteristic of test   
Unit  
Requirement  Test method or 
applicable 
standard  
Viscosity grade   22 32 46 68 ISO 3448  
Flash point  
Cleveland ope n cup, min.   
°C  
165  
175  
185  
195 ISO 2592  
Kinematic viscosity        
at –20 °C, max.  mm2/s  —d —d —d —d  
at –0 °C, max.  mm2/s  300 420 780 1 400  ISO 3104  
at –40 °C, max.  mm2/s  19,8 to 24,2  28,8 to 35,2  41,4 to 50,6  61,2 to 74,8   
at 100 °C, min.  mm2/s  4,1 5,0 6,1 7,8  
Pour point, max.  °C -21 -18 -15 -12 ISO 3016  
Water content, max.  mg/kg  5 000  5 000  5 000  5 000  ISO 12937  
ISO 6296  
Copper corrosion, 100 °C  rating  2 2 2 2 ISO 2160  DUS 2159 -4:2019  
© UNBS 2019  – All rights reserved  xiv 
 3 h, max.  
Rust prevention, procedure A, 
24 h — Pass  Pass  Pass  Pass  ISO 7 120 
Foam        
at 24 °C, max. (Sequence I)  
at 93 °C, max. (Sequence II)  ml 
ml 150/0  
80/0 150/0  
80/0 150/0  
80/0 150/0  
80/0 ISO 6247  
at 24 °C, max. (Sequence III)  ml 150/0  150/0  150/0  150/0   
Air release, 50 °C, max.  min 7 7 10 10 ISO 9120  
Elastomer comp atibilitya after 1 
000 h at given temperature        
NBR 1  °C 60 80 — —  
HNBR  °C 60 80 100 100  
FKM 2  
Change in shore A hardness, 
max.  °C 
grade  60 
±10 80 
±10 100 
±10 100 
±10 ISO 6072  
Change in volume, max.  % -3 to +10  -3 to +10  -3 to +10  -3 to +10   
Change in elongation, max.  % 30 30 30 30  
Change in tensile strength, 
max.  % 30 30 30 30  
Oxidation stability:  
TOST test, time to reach  
ΔTAN = 2 mg KOH/g, min.   
h  
1 000   
1 000   
1 000   
1 000   
ISO 4263 -3 
Load‑carrying properties,  
FZG A/8,3/90, min.  stage  b 10 10 10 ISO 14635 -1 
Vane pump, Procedure Ac 
Ring, max.  
Vane, max.   
mg  
mg  
120 
30  
120 
30  
120 
30  
120 
30  
ISO 20763  
f The requirements for two of the listed elastomer types shall be met. The values are minimum requirements  for standard reference 
elasto mers. The elastomers are suitable for guidance and selection of the correct sealing  material. Other materials and/or test conditions 
may be agreed upon bet ween supplier and customer. The applicability to the behaviour of the elastomer used in practice shou ld be 
considered.  
b Not applicable to Viscosity Grade 22.  
c There are currently no precision data for the method when non -Eaton/Vickers test cartridges (e.g. Conestoga USA, Inc. and Tokimec) 
are used. Consequently, no absolute mass loss limits can be stipu lated until the  precision of V104C pump cartridges from the new 
supplier has been determined. In the interim, the limits previously  established for Eaton/Vickers cartridges may be used for guidance. It 
should be noted that ISO 20763  supersedes BS 2000: Par t 281, IP 281 and DIN 51389. For fluids evaluated under the aforementioned 
methods,  the test data are considered to remain valid and no re -testing against ISO 20763 is required.  
 
Table 3  — Specifications for type HEES hydraulic fluids, synthetic esters  
 
Characteristic of test   
Unit  
Requirement  Test method 
or applicable 
standard  DUS 2159 -4:2019  
© UNBS 2019  – All rights reserved  xv 
 Viscosity grade   22 32 46 68 100 ISO 3448  
Flash point         
Cleveland open cup, min.  °C 165 175 185 195 205 ISO 2592  
Kinematic viscosity         
at 0 °C, max.  
at 40 °C, min. t o max.  mm2/s  
mm2/s  300 
19.8 -24.2 420 
2.,8 -35.2 780 
41.4-50.6 1 400  
61.2 -74.8 1 500  
90.0 -110 ISO 3104  
at 100 °C, min.  mm2/s  4.1 5.0 6.1 7.8 10.0  
Pour point, max.  °C -21 -18 -15 -12 -9 ISO 3016  
Water content, max.  mg/kg  1 000  1 000  1 000  1 000  1 000  ISO 12937  
ISO 6296  
Copper corrosion, 100 °C,  
3 h, max.  rating  2 2 2 2 2 ISO 2160  
Rust prevention, procedure A, 
24 h  Pass  Pass  Pass  Pass  Pass  ISO 7120  
Foam         
at 24 °C, max. (Sequence I)  ml 150/0  150/0  150/0  150/0  150/0   
at 93 °C, max. (Sequence I I) ml 80/0 80/0 80/0 80/0 80/0 ISO 6247  
at 24 °C, max. (Sequence III)  ml 150/0  150/0  150/0  150/0  150/0   
Air release, 50 °C, (75°C for  
ISO VG 100), max.  min 7 7 10 10 14 ISO 9120  
Elastomer compatibilitya after 
1 000 h at given temperature         
NBR 1  °C 60 80 80 — —  
AU °C 60 80 80 — —  
HNBR  °C 60 80 80 100 100  
FKM 2  
Change in shore A hardness, 
max.  °C 
grade  60 
±10 80 
±10 80 
±10 100 
±10 100 
±10 ISO 6072  
Change in volume, max.  % -3 - +10 -3  - +10 -3 - +10 -3 - +10 -3 - +10  
Change in elongation, m ax. % 30 30 30 30 30  
Change in tensile strength, 
max.  % 30 30 30 30 30  
Oxidation stability: Baader 
test, 110 °C, 72 h Increase in 
viscosity at 40 °C, max   20 20 20 20 20 ISO 4263 -3 
 
Load‑carrying  properties,  
FZG A/8,3/90, min.   
stage   
b  
10  
10  
10  
10  
ISO 14635 -1 
Vane pump.         DUS 2159 -4:2019  
© UNBS 2019  – All rights reserved  xvi 
 Procedure Ac 
Ring, max.   
mg  
120  
120  
120  
120  
120 ISO 20763  
Vane, max.  mg 30 30 30 30 30  
a The requirements for two of the listed elastomer types shall be met. The values are minimum requirements for standard refere nce 
elastomers. The elastomers are suitable for guidance and selection of the correct seal - ing material. Other materials and/or test 
conditions may be agreed upon between supplier and customer. The applicability to the behaviour of the elastomer used in p ractice 
should be considered.  
b Not applicable to Viscosity Grade 22.  
c There are currently no precision data for the method when non ‑Eaton/Vickers test cartridges (e.g. Cones - toga USA, Inc. and 
Tokimec) are used. Consequently, no absolute mass loss limit s can be stipulated until the precision of V104C pump cartridges from the 
new supplier has been determined. In the interim, the limits pre - viously established for Eaton/Vickers cartridges may be used for 
guidance. It should be noted that ISO 20763 superse des BS 2000: Part 281, IP 281 and DIN 51389. For fluids evaluated under the 
aforementioned methods, the test data are considered to remain valid and no re -testing against ISO 20763 is required.  DUS 2159 -4:2019  
© UNBS 2019  – All rights reserved  xvii 
 Table 4— Specifications for type HEPR hydraulic fluids, poly alphaolefins and other synthetic  hydrocarbons  
 
Characteristic of test   
Unit  
Requirement  Test method or 
applicable 
standard  
Viscosity grade   22 32 46 68 ISO 3448  
Flash point  
Cleveland open cup, min.   
°C  
165  
175  
185  
195  
ISO 2592  
Kinematic viscosity        
at 0 °C, max.  
at 40 °C, min. to max.  mm2/s  
mm2/s  300 
19.8 -24.2 420 
28.8 – 35.2 780 
41.4- 50.6 1 400  
61.2 – 74.8 ISO 3104  
at 100 °C, min.  mm2/s  4.1 5.0 6.1 7.8  
Pour point, max.  °C -21 -18 -15 -12 ISO 3016  
Water content  mg/kg  1 000  1 000  1 000  1 000 ISO 12937  
ISO 6296  
Copper corrosion, 100 °C,  
3 h, max.  rating  2 2 2 2 ISO 2160  
Rust prevention, procedure A, 
24 h  Pass  Pass  Pass  Pass  ISO 7120  
Foam        
at 24 °C, max. (Sequence I)  ml 150/0  150/0  150/0  150/0   
at 93 °C, max. (Sequence II)  ml 80/0 80/0 80/0 80/0 ISO 6247  
at 24 °C, max. (Sequence  III) ml 150/0  150/0  150/0  150/0   
Air release, 50 °C, max.  min 7 7 10 10 ISO 9120  
Elastomer compatibilitya after 1 
000 h at given temperature        
NBR 1  °C 60 80 80 — ISO 6072  
AU °C 60 80 80 —  
HNBR  °C 60 80 80 100  
FKM 2  
Change in shore A hardness, 
max.  °C 
grade  60 
±10 80 
±10 80 
±10 100 
±10  
Change in volume, max.  % -3 - +10 -3 - +10 -3 - +10 -3 - +10  
Change in elongation, max.  % 30 30 30 30  
Change in tensile strength, 
max.  % 30 30 30 30  
Oxida tion stability: TOST 
test, time to reach ΔTAN =  
2 mg KOH/g, min.   
h  
1 000   
1 000   
1 000   
1 000   
ISO 4263 -1 DUS 2159 -4:2019  
© UNBS 2019  – All rights reserved  xviii 
 Load carrying  
properties,  
FZG A/8,3/90, min.   
Stage   
b  
10  
10  
10  
ISO 14635 -1 
Vane pump,        
Procedure Ah  
Ring, max.   
mg  
120  
120  
120  
120 ISO 20763  
Vane, max.  mg 30 30 30 30  
a The requirements for two of the listed elastomer types shall be met. The value s are minimum requirements for standard reference 
elastomers. The elastomers are suitable for guidance and selection of the correct seali ng material. Other materials and/or test conditions 
may be agreed upon between supplier and customer. The  applicability to the behaviour of the elastomer used in practice should be 
considered.  
b Not applicable to Viscosity Grade 22.  
c There are currently n o precision data for the method when non -Eaton/Vickers test cartridges (e.g. Conestoga USA, Inc. and Tokimec ) 
are used. Consequently, no absolute mass loss limits can be stipulated until the  precision of V104C pump cartridges from the new 
supplier has bee n determined. In the interim, the limits previously  established for Eaton/Vickers cartridges may be used for guidance. It 
should be noted that ISO 20763  supersedes BS 2000: Part 281, IP 281 and DIN 51389. For fluids evaluated under the aforementioned 
metho ds, the test data are considered to remain valid and no re -testing against ISO 20763 is required.  
 
  
© UNBS 2019  – All rights reserved  1 
 
14 Annex B  
(informative)  
Guidelines for changing fluids from mineral -based oils to environmentally acceptable fluids  
Table B .1 — Guidelines for changing flu ids from mineral -based oils to environmentally acceptable fluids  
Change of liquid 
pressure medium  Elements to be checked to determine whether the installation is suitable for use of 
environmentally acceptable hydraulic fluids  Measures during and after cha ngeover  
From  To Reservoir ab 
temperature  Seals, Plastics, 
adhesives  Metallic 
materials  Filter 
elementsc Paint coating  Remaining 
residue 
volumed max Periods between oil 
changes  Periods between filter 
changes  
HH 
HL 
HM 
HV 
HDg 
Engine  
oils  
 
HETG  
  
-10℃ to 70℃ 
 Industrial  
elastomerse 
 Lead, tin and 
zinc in pure 
form are to be 
avoided.  
Alloys of these  
metals are 
subject to 
possible 
corrosion in 
conjunction with 
aged liquids  
and at elevated 
temperatures  
  
 
Zinc-coat 
elements are 
subject to 
attack   
 
Compatibility  with 
paint coating   
 
2percent  This 
is to ensure 
thorough 
cleaning, 
emptying and 
flushing of the 
installation.  
1 % 
 Periods between changes 
depend  upon    the  
installation and  the  
application  and have  to  
be  agreed  with  the 
manufacturer  of  the  
liquid. In order  to  
determine  the length of 
time between change 
overs, running 
investigations, for 
instance of water content, 
solid particle 
contamination, viscosity, 
NN and  IR, as  well   as  
spectrographic analyses, 
are necessary.  Filter change when 
converting  to  the  new  
liquid and after 50h further 
Changes  have  to  be 
established   bearing  in  
mind the installation and 
application details.  
 
 
HH 
HL 
HM 
HV HEES  -20℃to 80℃ Industrial 
elastomerse 
Plastics and 
soluble adhesive 
compou nds Lead, tin and 
zinc in pure 
form are to be 
avoided.  
Alloys of these 
metals are Paper filter 
cartridges and 
zinc-coated 
filter elements 
are subject to  Compatibility with 
paint coating.  2 % (target). 
This is to 
ensure 
thorough 
cleansing, 
emptying and  Periods between 
changes depend upon the 
installation and the 
application and have to be 
agreed with the 
manufacturer of the liquid. Filter changes when 
converting to the new liquid 
and af ter 50 h. Further 
changes have to be 
established bearing in mind 
the installation and DUS  2159 -4: 2019  
© UNBS 2019  – All rights reserved  2 
 HDg 
Engine  
oils  subject to 
possible 
corrosion in  
Conjunction 
with attack.aged 
liquids and at 
elevated 
temperatures.  
 
  flushing of the 
installation  
1 % In order to determine the 
length of time between 
changeovers, running 
investigations, for 
instance  
contamination, viscosity,  
NN and IR, as well as 
spectrographic analyses, 
are necessary.  
 application details  
Table 1 (continued)  
Change of 
liquid pressure 
medium  Elements to be checked to determine whether the installation is suitable for use of 
environmenta lly acceptable hydraulic fluids  Measures during and after changeover  
From  To Reservoirab 
temperature  Seals, plastics, 
adhesives  Metallic 
materials  
 Filter elementsc 
 Paint  
coating  
 Remaining 
residual 
volumed, max  Periods between  
oil changes  
 Periods betw een filter 
changes  
 
HH 
HL 
HM 
HV 
HDg 
Engine  
oils HEPR  ‑30 °C to  
+100 °C  
 Industrial 
elastomerse 
Plastics and 
soluble adhesive 
compounds.  
An  abrupt  
change from a 
mineral oil ‑based 
fluid to a HEPR -
based product 
could lead to 
leakage of 
gaskets  
This can lead to 
sealing problems  Lead, tin and 
zinc in pure 
form are to 
be avoided.  
Alloys of 
these metals 
are to 
possible 
corrosion in 
conjunction 
with aged 
liquids  at 
elevated 
temperatures  
 
 Paper filter  
Cartridges  
and zinc -coated 
filter elements are 
subject to attack  
 Compatibility with 
paint coating  2 % (target) . 
This  is  to 
ensure  
Thorough 
cleaning 
emptying and 
flushing of the 
installation  Periods between 
changes depend upon 
the installation and the 
application and have to 
be agreed with the 
manufacturer of the 
liquid  
In order to determine the 
length between ch ange 
overs ,running the 
investigations, for 
instance of water 
content, solid particle 
contamination, viscosity 
NN and IR , as well as 
spectrographic analyses 
are necessary  Filter changes when 
converting to the new 
liquid and after 50 h. 
Further changes hav e to 
be established bearing in 
mind the installation and 
application details - DUS  2159 -4: 2019  
© UNBS 2019  – All rights reserved  3 
 HH 
HL 
HM 
HV 
HDg 
Engine  
oils  
HEPGh -20℃ to+80℃ Industrial 
elastomerse 
Plastics and 
soluble adhesive 
compounds.  
Non-resistant e.g. 
poly‑carbonates, 
poly‑meth - 
acrylates  
 Frictional 
combinations 
with 
aluminum.  
Lead, tin and 
zinc in pure 
form are to 
be avoided 
as well as 
frictional 
combinations 
with 
aluminum.  
Alloys of 
these metals  
are  subject 
to possible 
corrosionf in 
conjunction 
with aged 
liquids  
and at 
elevated 
temperatures  Filter elements. 
Suction filters.  
Paper filter 
cartridges and zinc -
coated filter 
elements are 
subject to attack.  
 
 Com patibility with 
paint coating.  
 1 % (target).  
This is to 
ensure 
thorough 
cleansing, 
emptying and 
flushing of the 
installation.0,50 
% 
 Periods between 
changes depend upon 
the installation and the 
application and have to 
be agreed with  the 
manufacturer of th e 
liquid. In order to 
determine the length of 
time between 
changeovers, running 
investigations, for 
instance of water 
content, solid particle 
contamination, viscosity, 
NN and IR, as well as 
spectrographic analyses, 
are necessary  Filter changes when 
convert ing to the new 
liquid and after 50 h. 
Further changes have to 
be established bearing in 
mind the installation and 
application details. Higher 
percentages of mineral  
oil shorten the periods 
between change  
NOTE When changing from HETG, HEES and HEPR to HEPG , it is recommended for users to proceed in the same way as when changing from HL, HH, HM, HV to HEPG, due to possible miscib ility problems.  
a Higher temperatures have an unfavorable influence on compatibility with seals and ageing characteristics.  
b In hy dro systems, temperatures of up to 25 °C and higher can be permitted for a short time or locally.  
c Manufacturer to be consulted for suitability.  
 dThe number of flushes depends upon the installation. It is possible that the residual volumes quoted cause f iltration or foaming problems.  
e Recommended industrial elastomers. Refer to footnote c.  
f At present, there is no recognized procedure for assessment.  
g HD stands for heavy duty. To include fluid discrepancy and detergency.  
h A density of more than 1 g/ml  requires a reduction of about 20 % in the maximum permitted rotary speed of self ‑priming pumps.  
 
15 DUS  2159 -4: 2019  
© UNBS 2019  – All rights reserved  1 
 Bibliography  
[1] ISO 6743 -99, Lubricants, industrial oils and related products (class L) — Classification — 
Part 99: General  
[2] Lubricants, industrial oils and related products (class L) — Family H (Hydraulic systems) — 
Specifications f or hydraulic fluids in categories HETG, HEPG, HEES and HEPR  
  
© UNBS 2019  – All rights reserved  3 
 Certification marking  
Products that conform to Uganda standards may be marked with Uganda National Bureau of Standards 
(UNBS) Certification Mark shown in the figure below.  
The use of the UNBS C ertification Mark is governed by the Standards Act, and the Regulations made 
thereunder. This mark can be used only by those licensed under the certification mark scheme operated by 
the Uganda National Bureau of Standards and in conjunction with the releva nt Uganda Standard. The 
presence of this mark on a product or in relation to a product is an assurance that the goods comply with the 
requirements of that standard under a system of supervision, control and testing in accordance with the 
certification mark  scheme of the Uganda National Bureau of Standards. UNBS marked products are 
continually checked by UNBS for conformity to that standard.  
Further particulars of the terms and conditions of licensing may be obtained from the Director, Uganda 
National Burea u of Standards.  
 
  
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