DRAFT UGANDA STANDARD  
  DUS 2159 -3 
First Edition  
yyyy -mm-dd 
 
 
 Reference number  
DUS 2159 -3: 2019 
© UNBS 2019   
  
Hydraulic fluid — Performance Classifications — Part 3: 
Specifications for hydraulic fluids in categories HFAE, HFAS, 
HFB, HFC, HFDR and HFDU  
 DUS 2159 -3: 2019  
ii © UNBS 2019  – All rights reserved  
 Compliance with this standard does not, of itself confer immunity from legal obligations  
A Uganda Standard does  not purport 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, electronic 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  
Kampala  
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 -3:2019  
© UNBS 2019  – All rights reserved  iii 
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ ............................  iv 
1 Scope  ................................ ................................ ................................ ................................ ......................  1 
2 Normative references  ................................ ................................ ................................ ............................  1 
3 Terms and definitions  ................................ ................................ ................................ ...........................  3 
4 Viscosity classification  ................................ ................................ ................................ .........................  3 
5.1 General requirements  ................................ ................................ ................................ ...........................  3 
5.2 Performance categories  ................................ ................................ ................................ .......................  3 
5.3 Specific requirements  ................................ ................................ ................................ ...........................  3 
6 Packaging  ................................ ................................ ................................ ................................ ...............  3 
7 Labelling  ................................ ................................ ................................ ................................ .................  4 
8 Sampling  ................................ ................................ ................................ ................................ ................  4 
Annex  A (normative)  Laboratory/bench test requirements  ................................ ................................ ..........  5 
A.1 Specific requirements for the different ISO categories of hydraulic fluids ................................ ..... 5 
Bibliography  ................................ ................................ ................................ ................................ ......................  11 
 DUS 2159 -3: 2019  
iv © UNBS 2019  – All rights reserved  
 Foreword  
Uganda National Bureau of Standar ds (UNBS) is a parastatal under the Ministry of Trade , Industry and 
Cooperatives established under Cap 327 , of the Laws 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 National Enquiry Point on TBT  Agreement  of the World Trade Organisation (WTO).  
The work of preparing Uganda Standards is carried out throug h Technical Committees. A Technical 
Committee is established to deliberate on standards in a given field or area and consists of key stakeholders 
including government, academia, consumer groups, private sector and other interested parties.  
Draft Uganda St andards 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 Nationa l Standards Council.  
The committee responsible for this document is Technical Committee UNBS /TC 16, Petroleum , 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 cate gories HETG, HEPG, HEES and HEPR . DUS 2159 -3:2019  
© UNBS 2019  – All rights reserved  v 
 DRAFT UGANDA STANDARD  DUS 2159 -3: 2019  
 
© UNBS 2019  – All rights reserved  1 
 Hydraulic fluid — Performance Classifications — Part 3: 
Specifications for hydraulic fluids in categories HFAE, HFAS, 
HFB, HFC, HFDR and HFDU  
1 Scope   
This Draft Uganda Standard specifies performance requirements, samp ling and test methods for unused fire -
resistant and less -flammable hydraulic fluids of the categories HFAE, HFAS, HFB, HFC, HFDR and HFDU, 
and is intended for hydrostatic and hydrodynamic systems in general industrial applications  
Note : It is not intended  for use in aerospace or power -generation applications, where different requirements apply  
Types HFAE, HFAS, HFB, HFC and HFDR are “fire -resistan t” fluids as defined by DUS 2159 -1:2019 . Most 
HFDU fluids, while displaying an improvement in combustion behavi our over mineral oil, fall outside this 
definition and are more appropriately considered “less -flammable” fluids . 
2 Normative references  
The following referenced documents referred to in the text in such a way that some or all of their content 
constitutes requirements 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 760:1978, Determination of water — Karl Fischer method (Ge neral method)  
US ISO 3104:1994, Petroleum products — Transparent and opaque liquids — Determination of kinematic  
viscosity and calculation of dynamic viscosity  
US ISO 3170:2004, Petroleum liquids — Manual sampling  
DUS 2221:2019  Standard Test Method for Determination of Low Temperature Fluidity and Appearance o f 
Hydraulic Fluids of water content — Nitrogen purge method  
DUS 2222:2019 Standard Practice for Evaluating Compatibility of Mixtures of Hydraulic Fluids  
DUS ISO 3448:1992, Industrial liquid lubri cants — ISO viscosity classification  
DUS ISO 3733:1999, Petroleum products and bituminous materials — Determination of water — Distillation 
method  
DUS ISO 4259:2006, Petroleum products — Determination and application of precision data in relation to 
method s of test  
DUS ISO 4263 -2:2003, Petroleum and related products — Determination of the ageing behaviour of inhibited 
oils and fluids — TOST test — Part 2: Procedure for category HFC hydraulic fluids  
DUS ISO 4263 -3:2010, Petroleum and related products — Deter mination of the ageing behaviour of inhibited 
oils and fluids using the TOST test — Part 3: Anhydrous procedure for synthetic hydraulic fluids   
2 © UNBS 2019  – All rights reserved  
 DUS ISO 4404 -1:2012, Petroleum and related products — Determination of the corrosion resistance of fire  
resistant  hydraulic fluids — Part 1: Water -containing fluids  
DUS ISO 4404 -2:2010, Petroleum and related products — Determination of the corrosion resistance of fire  
resistant  hydraulic fluids — Part 2: Non -aqueous fluids  
DUS ISO 6072:2011, Rubber — Compatibility be tween hydraulic fluids and standard elastomeric materials  
US ISO 6247:1998, Petroleum products — Determination of foaming characteristics of lubricating oils  
US ISO 6296:2000, Petroleum products — Determination of water content — Potentiometric Karl Fische r 
titration  method  
DUS ISO 6618:1997, Petroleum products and lubricants — Determination of acid or base number — Colour  
indicator  titration method  
DUS ISO 6619:1988, Petroleum products and lubricants — Neutralization number — Potentiometric titration  
metho d 
DUS ISO 7745:2010, Hydraulic fluid power — Fire-resistant (FR) fluids — Requirements and guidelines for 
use 
DUS ISO 9120:1997, Petroleum and related products — Determination of air -release properties of steam 
turbine  and other oils — Impinger method  
DUS ISO 14935:1998, Petroleum and related products — Determination of wick flame persistence of fire -
resistant  fluids  
DUS ISO 15029 -1:1999, Petroleum and related products — Determination of spray ignition characteristics of 
fire resistant  fluids — Part 1: Spra y flame persistence — Hollow -cone nozzle method  
DUS ISO/TS 15029 -2:2012, Petroleum and related products — Determination of spray ignition characteristics 
of fire-resistant fluids — Part 2: Spray test — Stabilized flame heat release method  
DUS ISO 20763:200 4, Petroleum and related products — Determination of anti -wear properties of hydraulic 
fluid —Vane pump method  
DUS  ISO 20764:2003, Petroleum and related products — Preparation of a test portion of high -boiling liquids 
for the  determination of water content  — Nitrogen purge method  
DUS  ISO 20783 -1:2011, Petroleum and related products — Determination of emulsion stability of fire -resistant  
fluids — Part 1: Fluids in category HFAE  
DUS  ISO 20783 -2:2003, Petroleum and related products — Determination of emulsion stability of fire -resistant  
fluids — Part 2: Fluids in category HFB  
DUS  ISO 20823:2003, Petroleum and related products — Determination of the flammability characteristics of 
fluids  in contact with hot surfaces — Manifold ignition test  
DUS  ISO 20843:2011, P etroleum and related products — Determination of pH of fire -resistant fluids within  
categories HFAE, HFAS and HFC  
US ISO 20844:2004, Petroleum and related products — Determination of the shear stability of polymer -
containing  oils using a diesel injector no zzle 
EN 14832:2005, Petroleum and related products — Determination of the oxidation stability and corrosivity of  
fire-resistant phosphate ester fluids  DUS 2159 -3: 2019  
© UNBS 2019  – All rights reserved  3 
 3 Terms and definitions   
No terms and definitions are listed in this document.  
ISO and IEC maintain terminological databases for 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 sha ll be classified basing on the ISO viscosity classification, as per 
designations indicated in US ISO 3448 5  
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, compounded 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.  
The appearance of the delivered oils shall be clear and bright and free of any visible particulate matter, under 
normal visible light at ambient temperature.  
To determine stability, when tested in accordance with DUS 2221:2019 the Hydraulic fluid shall remain clear 
and homogeneous, and shall show no evidence of separation of components and no evidence of colour 
change.  
To determine compatibility, when tested in accordance with DUS 2222:2019 , the Hydraulic fluid shall be 
compatib le 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 meet one of the 
performance categories HH , HL, HM, HV and HG as specified in DUS 2159 -2:2019.  
The majority of test methods specified within Tables 1 to 3 contain a statement of precision (repeatability and 
reproducibility). ISO 4259, which covers the use of precision data in the interpretation of  test results, shall be 
used in cases of dispute  
NOTE:  The consumer shall refer to the owner’s or operator’s manual for recommended category of Hydraulic fluid to be 
used in a specific Hydraulic system . 
5.3 Specific  requirements  
In addition to meeting th e requirements given in Clause 5.1 and 5.2  above, hydraulic fluid shall comply with 
specific specifications provided hereafter in Annex A . 
6 Packaging  
The condition of the drums or smaller containers and the bulk tankers into which the hydraulic fluid is f illed 
shall have 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, containers shall be firmly secured with a tamper -proof seal.   
4 © UNBS 2019  – All rights reserved  
 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) viscosity according to ISO viscosity grading   
e) net content;  
f) origin of the product/Made in; and  
g) date of production an d the batch number  
h) expiry date  
i) warnings and cautions  
8 Sampling  
Sampling of hydraulic fluids shall be carried out in accordance with the appropriate procedure described in 
ISO 3170.  DUS 2159 -3: 2019  
© UNBS 2019  – All rights reserved  5 
 Annex  A 
(normative)  
 
Laboratory/bench test requirements  
A.1 Specific r equirements for the dif ferent ISO categories of  hydraulic fluids  
Table 1 — Requirements for fluids in categories HFAE and HFAS  
 
Characteristic or test   
Unit Specification   
Test method  Category HFAEabcd Category HFASabcd 
Composition:   oil-in-water emulsio ns 
typically containing  
 95 % water ( m/m), (5 °C 
to 50 °C; ISO 7745)  chemical solutions in water 
typically containing  
 95 % water ( m/m), (5 °C 
to 50 °C; ISO 7745)   
Viscosity at 40 °C, (max)  mm2/s 5 5 ISO 3104  
Water content  % (m/m) 
% (m/m) 95 
- - 
95 ISO 3733  
ISO 6296i 
Foaming tendency/stability at  
25 °C, (max)  
50 °C , (max)  
25 °C, (max)   
ml/ml  
 ml/ml  
ml/ml   
300/10  
300/10  
300/10   
300/10  
300/10  
300/10  ISO 6247  
pH at 20 °C   6,7 to 10,0  6,7 to 10,0  ISO 20843  
Emulsion stability (50 °C/600 h)  
 free oil,  (max)  
 cream,  (max)  rating  
% (V/V) 
% (V/V) 2A to 2R  
trace  
0,5 - 
- 
- ISO 20783 -1 
Corrosion protection  
visual rating of metals, (max)  
visual rating of the  fluid 
mass changes of metal strips, (max)  
-steel, copper and  brass  
-aluminium  
-zinc  
Rating  
 rating  
mg  
3 
e 
 
5 to 11 
5 to 5 
5 to 22  
3 
e 
 
5 to 11 
5 to 5 
5 to 22 ISO 4404 -1 
Elastomer compatibility: NBR 1f, EPDM 1f and 
FKM 2i elastomers, 60 °C/168 h  
relative volume change ............. (min) 
............................................ .... (max)  
relative hardness change ..........  (min) 
................................................ (max)  
change in tensile  strength   
 
% 
% 
IRHDg  
IRHDg 
%  
 
0 
7 
7 
2 
h  
 
0 
7 
7 
2 
h ISO 6072   
6 © UNBS 2019  – All rights reserved  
 elongation at  break  % 
 h h 
a These products are normally sup plied as concentrates and are diluted with water by the end user. To ensure the rapid and complete mixing of the finished 
fluid, the viscosity of the concentrate at 20 °C should be 350 mm2/s maximum.  
b The limits given in this table can be applied at the d ilution recommended by the supplier when using water selected from one of the following sources:  
1. test waters listed in ISO 4404 -1 and in ISO 20783 -1; or 
2. distilled or de -ionized water; or  
3. mains water supplied by the user.  
Tests should be carried out before commercial use and the results, if reported, shall indicate the type of (test) water and the dilution level used.  
C The viscosity of these fluids is very low and they may be used only in equipment especially designed for such products.  
d As a result of the ir very high water content, these fluids are expected to possess excellent fire resistance.  
e Test limits are be negotiated between the supplier and the user.  
f NBR 1, EPDM 1 and FKM 2 are standard reference elastomers, the compositions of which are given in ISO 6072. They are the elastomer types most 
widely used, but not exclusively so, with the above fluids. While providing a useful guide to compatibility with HFAE and HFA S fluids, they can give results 
that are different from commercially available rubbe rs of the same nominal type. If doubt exists as to their compatibility, contact the elastomer manufacturer.  
g International Rubber Hardness Degree.  
h Report only on request.  
i ISO 6296 covers the mass fraction range 0,003 % (m/m) to 0,100 % (m/m). To use I SO 6296 to measure the water content of HFAS fluids, proceed as 
follows:  
— use a 100 µl syringe to take the test sample;  
— dry the 100 µl syringe as described in ISO 6296:2000, 7.2.3;  
— withdraw a 50 µl to 100 µl sample and titrate in accordance with ISO 6296:20 00, 7.2.5.  
Note that the precision of this procedure may differ from the values given in ISO 6296.  
 
Table 2 — Requirements for fluids in categories HFB and HFC  
 
Characteristic or test   
Unit Specification   
Test method  Category HFBa Category HFCa 
Compo sition   water -in-oil emulsions, 
typically containing  
 40 % water (% m/m) (5 
°C to 50 °C,  
ISO 7745)  water polymer 
solutions, typically 
containing  
 35 % water (% m/m) 
(20 °C to 50 °C, ISO 
7745)   
Viscosity grade (ISO 3448)   46; 68; 100  22; 32; 46; 68   
Water content  % (m/m) 
% (m/m) - 
40 35 
- ISO 6296b 
ISO 3733  
pH at 20 °C   - 6,7 to 10,0  ISO 20843  
Corrosion protection:     ISO 4404 -1 
visual  assessment  of the metals ,  (max)  rating  3 3  DUS 2159 -3: 2019  
© UNBS 2019  – All rights reserved  7 
  mass changes of strips,  (max)  mg    
-steel, copper and  brass  
-aluminium   5 to 11 
5 to 5 5 to 11 
5 to 5  
-zinc   5 to 22 5 to 22  
Foaming tendency/stability at     ISO 6247  
25 °C , (max)  ml/ml  - 300/10   
50 °C , (max)  
25 °C , (max)  ml/ml  
ml/ml  - 
 
- 300/10  
300/10   
Air release at 50 °C , (max)  min - 20; 20; 25; 25  ISO 9120  
Emulsion stability:     ISO 20783 -2 
1) 1 000 h at 20 °C,      
-surface  oil , (max)  
-accumulated  free water  , (max)  ml 
ml 10 
2 - 
  
-change in water content at 425 ml, (max)  
-change in water content at 125 ml, (max)  % 
% 5 
5 - 
-  
2) 48 h at 70 °C  
-surface  oil, (max)  
-accumulated  free water  , (max)   
ml  
ml  
3 
1  
- - ISO 20783 -2 
3) 336 h at -10 °C/168 h at 20 °C     ISO 20783 -2 
-surface  oil , (max)  ml 2 -  
-accumulated  free water  , (max)  ml 1 -  
-change in water content at 5 ml, (max)  % 15 -  
-mean change in water content at 5 ml , (max)  % 10 -  
Shear stability: 17,5 MPa (175 bar)/250 cyclesf    ISO 2084 4 
-viscosity  change  at 20 °C, (max)  %  15 -  
-viscosity  change  at 40 °C, (max)  %  15 -  
-viscosity  change  at 100 °C, (max)  % - -  
-pH change ,   (max)   -  1,0  
-water  content  change , (max)  % 5 8  
-acid number  change  , (max)  mg KOH/g   0,50 - ISO 6618 
ISO 6619  
Elastomer compatibility: 60 °C/168 h  
  NBR 1  elastomerd 
-relative volume change , ( min) 
......................................  , (max)  
-relative hardness change , ( min) 
......................................  , (max)  
  
 
% 
%  
IRHD  
IRHD  
  
 
0 
7 
7 
2 
  
 
0 
7 
7 
2 ISO 6072  
Fire resistance ; Spray ignition characteristicse     ISO 15029 -1e  
8 © UNBS 2019  – All rights reserved  
 -time to extinguishment  of flame , (max)  
 s 30 
 30 
 
Wick flame persistence  
-mean  flame  persistence ,  (max)   
s  
60  
60 ISO 14935  
Manifold ignition test  
 -ignition temperature , ( min)  
°C 
  
650 
  
600 
 ISO 20823  
Ageing propertiesf 
-pH value  after  test , ( min) 
- insoluble, (max)   
 
%  
- 
 -  
4 
4 ISO 4263 -2 
Lubrication performance Vane pump  
-total of ring and vane wear, (max)   
mg  
-  
g ISO 20763  
a These fluids are supplied as the finished product.  
b   ISO 6296 covers the mass fraction range 0,003 % (m/m) to 0,100 % (m/m). To use ISO 6296 to measure the water content of H FC fluids, proceed as  
follows:  
— use a 100 µl syringe to take the test sample;  
— dry the 100 µl syringe as described in ISO 6296:2000, 7.2.3;  
— withdraw a 50 µl to 100 µl sample and titrate in accordance with ISO 6296:2000, 7.2.5.  
Note that the precision of this procedure may differ from the values given in ISO 6296.  
c For fluids with a viscosity greater than 10 mm2/s at 20 °C.  
d NBR 1 is a standard reference elastomer, the composition of which is given in ISO 6072. It is the type of elastomer most wide ly used with the above  
fluids, but not exclusively so. It provides a useful guide to the compatib ility of this seal type with HFB and HFC fluids, but can give results that are different 
from commercially available elastomers of the same nominal type. If doubt exists as to the compatibility, contact the elastom er manufacturer.  
eThe methods published as  parts of ISO 15029 (see also Annex A) measure different fluid characteristics under conditions that are not necessarily  
comparable. However, performance under at least one test condition is required. The method is therefore to be agreed between the end us er and the fluid 
supplier in accordance with national or other requirements. ISO/TS15029 -2 is currently under development and limits have not yet been established. These 
are to be agreed between the end user and the fluid supplier. Where data are reported,  reference shall be made to the method used.  
f The test duration is 200 h.  
g In view of the non -availability of test cartridges from the original supplier, new sources are currently being investigated. As yet, no precisio n data are  
available on the alterna tive cartridges when testing the above fluid types and no limits can, therefore, be specified. Until these data are available , it is 
recommended that the limits previously specified in ISO 20763 be used for guidance only. For HFC fluids, this means a vane and ring mass loss of 
  50 mg 
and 
  180 mg, respectively.  
 
Table 3 — Requirements for fluids in categories HFDR and HFDU  
 
Characteristic or test   
Unit Specifications   
Test method  Category HFDRa Category HFDUa DUS 2159 -3: 2019  
© UNBS 2019  – All rights reserved  9 
 Composition   synthetic fluids free  of 
water consisting of 
phosp hate esters ( 20 °C  
to 70 °C/150 °Cb, ISO 
7745)  synthetic fluids free of 
water and of other 
composition  
(20 °C  to 70 °C/150  
°Cb, ISO  7745)   
Viscosity grade (ISO 3448)   15; 22; 32; 46; 68; 100  15; 22; 32; 46; 68; 100   
Water content,  (max)  % (m/m) 0.1 0.1 ISO 760 ISO 
20764c 
Foaming tendency/stability at  
25 °C ,  (max)  
93 °C ,  (max)  
25 °C ,  (max)   
ml/ml  
ml/ml  
ml/ml   
300/10  
300/10  
300/10   
300/10  
300/10  
300/10  ISO 6247  
Air release at 50 °C ,  (max)  min 8; 10; 12; 15; 25; 30  8; 10; 12; 15; 25; 30  ISO 9120  
Corrosion protection  
visual assessment of metals ,  (max)  
mass changes of metal strip ,  (max)  
-steel, copper and  brass  
-aluminium  
-zinc  
Rating  
 mg  
3 
 
5 to 11 
5 to 5 
5 to 22  
3 
 
5 to 11 
5 to 5 
5 to 22 ISO 4404 -2 
Shear stability, 17, 5 MPa (175 bar)/250 cycles  
-viscosity change at 20 °C ,  (max)  
-viscosity change at 40 °C  ,  (max)  
-viscosity change at 100 °C  ,  (max)  
-acid number  change  ,  (max)   
% 
% 
% 
mg KOH/g   
 10 
 5 
 7 
 0,5  
 10 
 5 
 7 
 0,5 ISO 20844  
 
 
 
ISO 6619  
Elastomer com patibility: 100 °C/168 h  
FKM 2e, EPDM 1e types (HFDR  fluids)  
FKMe, NBR 1e, NBR 2e types (HFDU  fluids)  
relative volume change,  (min) 
.................................... ,  (max)  
 relative ha rdness change, (min) 
........ ...............................  ,  (max)  
 
 
% 
% 
 IRHD  
IRHD   
 
 
0 
7 
7 
2  
 
 
0 
7 
7 
2 
 ISO 6072  
Fire resistance ; Spray ignition characteristicse 
-time to extinguishment  of flame  ,  (max)   
s  
30  
30 ISO 15029 -1e 
Wick flame persistence  
-mean  flame  persistence  ,  (max)   
s  
60  
- ISO 14935  
Manifold ignition test  
 -ignition temperature,  (min)  
°C  
700  
400 ISO 20823  
Oxidation stability  
-acid number increase ,  (max)  
mass losses ,  (max)  
⎯ iron  
mg KOH/g  
mg 
  
1,5 
 
1  
- 
 
- EN 14832  
 
 
  
10 © UNBS 2019  – All rights reserved  
 ⎯ copper  
Oxidation life, (min)   
h 2 - 
100  
ISO 4263 -3 
Lubrication performance Vane pump  
-total of ring and vane wear , (max)  
mg  
f  
f ISO 20763  
 
a These fluids are supplied as the finished product.  
b The higher temperature indicates the approximate upper limit for short -term operation. This will depend upon whether the application is hydro static or 
hydrodynamic and, for HFDU fluids, on the chemical composition of the fluid. Where doubt exists, clarification should be soug ht from the equipment 
manufacturer and/or fluid supplier.  
c ISO 20764 is applied in instances where interference by certa in chemicals is to be avoided  
d   EPDM 1,  FKM 2, NBR 1 and NBR 2 are standard reference elastomers, the  compositions of which are given in  ISO 6072. The y are the elastomer   
types most widely used with the above fluids, but not exclusively so. They will  provide a useful guide to compatibility with HFDR and HFDU fluids, but may 
give results that are different from commercially available elastomers of the same nominal type. EPDM 1 and FKM 2 are normall y suitable for use with HFDR 
fluids with the exception of the combination of FKM 2 and alkyl phosphate esters. The NBR 1 and NBR 2 reference elastomers are not suitable for use wit h 
HFDR fluids and NBR 1 might not be suitable for use with all HFDU fluids. If doubt exists as to their compatibility, contact the elastomer manufacturer.  
e The methods published as parts of ISO 15029 (see also Annex A) measure different fluid characteristics under conditions tha t are not necessarily 
comparable. However, performance under at least one test condition is required. The m ethod is therefore to be agreed between the end user and the fluid 
supplier in accordance with national or other requirements. ISO/TS 15029 -2 is currently under development and limits have not yet been established. These 
are to be agreed between the end us er and the fluid supplier. Where data are reported, reference shall be made to the method used.  
f In view of the non -availability of test cartridges from the original supplier, new sources are currently being investigated. As yet, no precisio n data are 
available for alternative cartridges and therefore no limits can be specified. Until these data are available, it is recommended  that the limits previously 
specified in ISO 20763 be used for guidance only. For both HFDR and HFDU fluids this means a vane and r ing weight loss of < 30 mg and < 120 mg, 
respectively.  
 DUS 2159 -3: 2019  
© UNBS 2019  – All rights reserved  11 
 Bibliography  
[1] CEN/TR 14489:2005, Fire -resistant hydraulic fluids — Classification and specification — Guidelines on 
selection for the protection of safety, health and the environment   
 DUS 2159 -3: 2019  
© UNBS 2019  – All rights reserved  13 
 Certificat ion 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 Certification 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 relevant Uganda Standard. The 
presence of this mark on a product or in relatio n 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 Bureau of Standards.  
 
 DUS 2159 -3: 2019    
 
ICS nn.nnn.nn  
Price based on nn pages  
© UNBS 2019 – All rights reserved