IS 15178: Hydraulic Fluid Power - Fire-Resistant (FR) Fluids - Guidelines For Use

17 Pages·2002·1.6 MB·English

by  Bureau of Indian Standards

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IS 15178 (2002): Hydraulic Fluid Power - Fire-Resistant
(FR) Fluids - Guidelines For Use [PGD 16: Fluid Power]
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Satyanarayan Gangaram Pitroda
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“!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता हहहहै””ै”
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“Knowledge is such a treasure which cannot be stolen”

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Indian Standard
HYDRAULIC FLUID POWER — FIRE-RESISTANT (FR)
FLUIDS — GUIDELINES FOR USE
ICS 75.120
~......

@ BIS 2002
BUREAU OF INDIAN ST AN DAR&
MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG
NEW DELHI 110002
June 2002 Price Group 6
I
I
Basic Fluid Power Sectional Committee, BP 14
NATIONAL FOREWORD
This Indian Standard which is identical with ISO 7745:1989 ‘Hydraulic fluid power — Fire-resistant
(FR) fluids – Guidelines for use’ issued by the International Organization for Standardization (ISO)
was adopted by the Bureau of Indian Standards on the recommendation of the Basic Fluid Power
* ,,
Sectional Committee and approval of the Basic and Production Engineering Division Council.
The text ofthe ISO Standard has been approved as suitable forpublication as Indian Standard without
deviations. Certain conventions are, however, notidentical tothose used inIndian Standards. Attention
is particularly drawn to the following:
a) Wherever the words ‘International Standard’ appear referring to this standard, they should be
read as ‘Indian Standard’.
b) Comma (,) has been used as a decimal marker in the International Standard while m Indian
Standards, the current practice isto use a point (.) as the decimal marker.
Inthisadopted standard, reference appears tocertain International Standards forwhich Indian Standards
also exist. The corresponding Indian Standards which are to be substituted intheir places are listed
below along with their degree of equivalence for the editions indicated:
, International Standard Corresponding Indian Standard Degree of
Equivalence
ISO 1629 : 1995 Rubber and Iatices IS 6611:1988 Symbols for rubbers and Technically
— Nomenclature Iatices (first revision) Equivalent
LSO 3448 : 1992 industrial liquid IS 9466:1980 Viscosity classification of do
1s0
lubricants — viscosity industrial liquid lubricants
----
classification
ISO 5598:1985 Fluid power systems IS 10416:1992 Fluid power systems and Identical
and components — Vocabulary components — Vocabulary (first

revision)

ISO 6702:1986 Hydraulic fluid power IS 15179:2002 Hydraulic fluid power — do
— Compatibility between elastomeric Compatibility between elastomeric
materials and fluids materials and fluids
The technical committee responsible forthe preparation ofthisstandard has reviewed the provisions of
the following ISO Standard and hasdecided that itisacceptable foruse inconjunction withthisstandard:
ISO 6743-4:1982 Lubricants, industrial oils and related products (class L) — Classification —
Part 4: Family H (Hydraulic systems)
a
For the purpose ofdeciding whether a particular requirement ofthis standard iscomplied with, the final
value, observed or calculated, expressing the result of a test or analysis, shall be rounded off in
accordance with IS2:1960 ‘Rules forroundingoffnumerical values (revisec$. The number ofsignificant
places retained in the rounded off value should be the same as that of the specified value in this
standard.
-
IS 15178:2002
ISO 7745:1989
*
Indian Standard .
HYDRAULIC FLUID POWER — FIRE-RESISTANT (FR)
FLUIDS — GUIDELINES FOR USE
O Introduction 3 Definitions
Inhydraulic fluidpower systems, power istransmitted andcon- Forthe purposes ofthis International Standard, the definitions
trolled through a liquid under pressure within an enclosed cir- given in ISO 5588 and the following definition apply.
cuit. One kind of fluid isafire-resistant fluid (see clause 3 for
definition). Fire-resistant properties vary widely among the fire-resistant (FR) fluid: Fluiddifficult to ignite which shows
types offluids, little tendency to propagate flame.
NOTE – The definitionof “fire-resistantfluid”givenistakenfrom
1 Scope and field of application ISO5596,butitisrepeatedhereforthesakeofconvenience.
This International Standard provides guidelines detailing, for
the various categories of fire-resistant fluids, operational 4 Hydraulic systems – Applications, hazards
characteristics, advantages anddisadvantages, andthefactors and general precautions
affecting the choice to be made amongst these various
categories. ...
4.1 General
This International Standard also specifies precautions which
should beadopted toreduce difficulties arisingfrom the useof Normal fluid pressures inhydraulic power systems range upto

such fluids, as well as the precautions which are necessary 4000 kPa1}(400 bar). Itfollows that anylackofintegrity inthe
when replacing fluids with fluids from differe n t categories. construction of a system or any burst or even small leak can
lead to a projection of fluid over a considerable distance.
The installation of hydraulic circuits with respect to fire- Should thefluid beflammable, thiscan inmany circumstances
resistant fluids isalsodescribed inthis International Standard. give riseto a seriousfire hazard.
2 References 4.2 Causes of fire
Failure of piping (particularly at joints), failure of valves,
ISO 1629, Rubber and Iatices – Nomenclature.
gaskets orfittings, pulling out oftubing from fittings, and rup-
ture of flexible hoses have been the principal causes of fluid
ISO 3448, Industrial liquid lubricants – ISO viscosity classifica-
being released from asystem.
tion.
The release of fluid under pressure where there isan ignition
ISO 5598, Fluid power systems and components —
source, for example molten metal, gas burners, sparks, elec-
Vocabulary.
tricalequipment and hotmetalsurfaces havebeenthecauseof
many hydraulic fluid fires. Evenfrictional heating may produce
ISO 8072, Hydraulic fluid power – Compatibility between
temperatures sufficient to cause spontaneous combustion
elastomeric materials and fluids.
(auto-ignition) offluid. Fireshave occurred duetothe acciden-
talormistaken disconnection of hydraulic piping orhosewhile
ISO 67434, Lubricants, industrial oils and related products
under pressure. Slow leaks into absorbent surfaces, such as
(class L) – Classification – Part 4: Family H (Hydraulic
lagging, may alsosupport combustion.
systems).
1) 1Pa= 1N/m2; l bar= 10sPa
1
—--4
IS 15178:2002 .
ISO 7745:1989
4.3 Generai precautions devices be incorporated within the hydraulic reservoir to
operate inthe event of high fluid temperatures occurring.
4.3.1 Major hazards
4.3.4 Fluid degradation
Itwill beappreciated that the summary of major hazards given
Chemical changes can take place inthe fluid during use, par-
below is not exhaustive and elso that the comment ismerely
ticularly at abnormal operating temperatures. The presence of
good engineering practice applicable equally tosystems where
contaminants accelerates the degradation process. When in-
either mineral oilsorfire-resistant fluids are inuse. The follow-
stallations require reservoir heating for coldstart-up, the rating
ing constitute major hazards:
of the heater shall be strictly controlled to avoid thermal
degradation.
a) leaks (see4.3.2);
b) highfluid temperature (see4.3.3); 4.3.5 Faulty installation and maintenance
c) fluid degradation (see4.3.4); Many failuresofhydraulicequipment canbeattributed tofaulty
installation and/ or maintenance.
d) faulty installation and maintenance (see4.3.5).
Failuretoobserve basicprecautions inthestorage andhandling
of fluid, failure to take adequate precautions to prevent the
4.3.2 Leaks ingress of contaminants during servicing, etc. are typical
examples.
Leaks can be caused by the following occurrences:
4.3.6 Fluid disposal
a) failure of asealing device (see8.7.3);
Fire-resistant fluidsshallbedisposedof inaccordance with the
b) failure of the fluid conductor – pipes, hoses, coup- national regulations inforce.
lings, etc.;
c) faulty assembly work. 5 Requirements for fire-resistant hydraulic
fluids
4.3.2.1 Sealing materials
5.1 Property requirements
Onlysealingmaterials that arecompatible with thefluidshallbe
used. Such devices shall be installed and used correctly inac- To perform satisfactorily in hydraulic systems the functional
cordance with [he supplier’s recommendations. fluid shallbefire-resistant and possessthe properties specified .---
in5.1.l to 5.1.10.
4.3.2.2 Fluid conductors
5.1.1 The functional fluid shallbefluid enough at allworking
Conductors shall bemounted and secured in such away asto temperatures toflow readilythrough thesystem andtoaccom-

reduce the effect of vibration. Careful consideration shall be modate rapid changes invelocity and pressure.
giventothesitingofcomponents and routing ofconductors to
avoid the possibilityofphysical damage. Inmany instances the
5.1.2 At the same time thefluidshallbeviscousenough atall
provision of protective channeling or metal guards is recom-
working temperatures to prevent unwanted leakage across
mended. Wherever possible conductors should not be routed
working clearances wherever a pressure differential exists
adjacent to other services, particularly electrical supplies.
across them.
4.3.2.3 Assembly work 5.1.3 The fluid shall be of sufficient viscosity and adequate
film strength to lubricate working parts effectively under both
Itisessentialthat work carried out on hydraulic installations be hydrodynamic and boundary conditions over the working
undertaken and supervised by competent staff. temperature range.
4.3.3 High fluid temperature 5.1.4 The fluid shall be compatible with construction
materials used inthe system and shall be non-corrosive.
The operating temperature ofawell-designed hydraulic system
should not normally exceed 50 ‘C (pump inlet temperature).
5.1.5 The fluid shallhave thermal stability and besuitable for
Any deviation from this shall be the subject of agreement be-
useat the highest expected operating temperature.
tween the supplier and the purchaser and in any such agree-
ment the fluid type, operating and ambiant temperature and
any other special conditions which apply should bespecified. 5.1.6 The fluid shall have chemical stability to give adequate
working life.
Highoperating temperatures reducefluidviscositywhich great-
ly increases the potential leakage rate and may render the 5.1.7 The fluid shallreleaseentrained air readily and not pro-
system lessefficient. It isrecommended that thermal shut-off vide astable foam.

2
—
IS 15178:2002
ISO 7745: 1989
5.1.8 The fluid shall separate readily from contaminants – HFB
encountered innormal usewithout chemical reaction.
– HFC
5.1.9 Thesurface tension of the fluid shallbelow enough to – HFD
give“wattability” but notlow enough tomake sealing difficult.
claaaifiedin 1S067434
} 5.1.10 The fluid should preferably be shear stable, i.e. its
Each categow isdivided into seven viscosity grades except for
viscosity should not permanently change unduly with applied
category HFAE, which isdivided into five viscosity grades (see
shear inasystem.
6.2.1), taken from those specified inISO 3446:
5.2 Other requirements – ISO VG 10
– ISO VG 15
The following fluidcharacteristics, atfirstusaand inthecourse
of use, shall be considered insystem design: – ISO VG 22
a) case of filtration; – ISO VG 32
b) relative density in relation to suction head of pump; – ISO VG 46
c) vapour pressurewhich should notgiverisetocavitation – ISO VG 66
at pump suction inlet;
– ISO VG 10U
d) fire-resistant qualities;
These grades correspond to the mean viscosity of the grade
defined by a minimum-maximum viscosity range expressed at
e) non-toxicity of the fluid and vapours produced.
40 ‘c.
6.1.4 The mixing of fire-resistant fluids of different categories
6 Characteristics of fire-resistant hydraulic shallnottake place. Itisalsoill-advisedtomixfluidsofthesame
fluids and factors affecting choice category butofdifferent origins,unlessthecompatibility ofsuch
hasbeanclearly established.
6.1 General Moreover, the replacement of hydraulic fluids of different
categories calls for special precautions and as such reference ,-
shallbe made to clause9.
6.1.1 Fire-resistant (FR) fluids have been designed for safety
reasons to replace conventional mineral oils in all applications
where hydraulic systems are operatin g in close proximify to 6.2 Classification of fluids
naked flames, molten matarial or oth e r high-temperature
sources, or specifically in hazardous emkonments where fire 6.2.1 Oil-in-water emulsions (category HFAE)
and/or explosion riskshave to be reduced to a minimum. It is
alsonecessarythatsuchfluidsshallresistspontaneous combus- NOTE– TheclassificationinISO6743-4divideacategoryHFAintotwo
tion ifallowed to come into contact with hotsurfaces orabsor- sub-categories,HFAE(oil-in-wateremulsions)andHFAS(chamicalsolu-
bent materials into which the fluid may have become im- tionsinwatar).
pregnated.
Oil-in-water emulsions, which have only minimal lubricating
value, are used in many systems. Their major advantage over
6.1.2 Fluidsused asfire-resistant hydraulic media obtain their plainwater istheirabilitytoprovideameasureofrustprotection.
fire resistanceby one of two following means
These materials are very fire-resistant, but are generally un-
eitherfrom the presence ofwater, or suitable for useinhigh-rated systems due to their low viscosity
and poorlubricity. Having such high proportions ofwater, they
from their chemical composition. also havetemperature limitations.
Waterr readilyavailableandtrulynon-flammable, wasusedinthe Oil-in-water emulsions normally contain up to a maximum of
earliestsystems butwater hasavery lowviscosityandisapoor 10 YO ofaolubla oildispersed inwater.
lubricant. Apart from theobvioustemperature limitation, theuse
ofwater alsogave risetoproblems ofcorrosionanderosion. For A minimum concentration oftheemulsionisnecessarytoensure
these reasons, plainwater cannot be usedinsystemsthe com- satisfactory corrosion protection.
ponents of which need to be lubricated by the hydraulic fluid.
Such emulsions are normally prepared on site by the user, ac-
cording to the fIuidsupplier’s recommendation.
6.1.3 Fire-resistantfluids are assignedfour categories:
Category HFAE isdivided into viscosity grades 10, 15, 22, 32
– HFAE and 46.

3
IS 15178:2002
ISO 7745:1989 ——.
----
“
6.2.2 Water-in-oil emulsions (invert emulsions) – HFDS: synthetic fluids cormaining no water and con-
(category HFB) sistingof chlorinated hydrocarborw.
Water-in-oil emulsions are dispersions of finely divided water – HFDT: synthetic fluide containing no water and con-
droplets in a continuous phase of mineral oil with special sisting of mixtures of phosphate ester and chlorinated
emulsifiers, stabilizers and inhibhors. They are supplied ready hydrocarbons.
for use and normally contain approximately 40 ‘A of water.
Changes in water content can reduce stability and/or fire – HFDU: synthetic fluidscontaining nowater and ofother
resistance. compositions.
Water-in-oil emulsions have viscosities similar to normal This category isdivided into viscosity grades 15,22, 32, 46, 68
mineral hydraulic oils and exhibit quite good lubricating and and 100.
anti-corrosive properties. The viscosity isnon-Newtonian and
mayvaryfrom one partofasystem toanother according tothe This category of fire-resistant fluids has good lubricating and
shear forces applied. Due to this viscosity characteristic and anti-wear properties, good storage stability and resistance to
high vapour pressure, pump inlet conditions have to be care- hightemperatures. Incertain casestemperatures upto 1XI “C
fully designed soasto avoid cavitation. can be permitted, but at such temperatures the fluid may be
subject to rapid deterioration and shallbe checked frequently.
Category HFB is divided into viscosity grades 22, 32, 46, 88
and 100. Category HFD fluidsarefire-resistant byvirtueoftheirchemical
composition and, when suitably inhibited, are compatible with
Fireresistance isimpaired by continuous water evaporation or most metals and give good protection agairmt rustand corro-
emulsion instability. sion. HFD fluids arevariable intheir toxicity. Generally speak-
ing, they exhibit poor viscosity/temperature relationships,
although certain products docontainviscosityindeximprovers.
6.2.3 Water polymer solutions (category HFC)
The majority of HFD fluids are sensitive to the presence of
NOTE– ISO6743-4designatesHFCfluidsas“wsterpolymersolu-
water or humidity, capable of causing corrosion and affecting
tions”;theyarealsoknownas“glycolsolutions”,“polyglycolsol-
utions”or“waterglycols”. the chemical stability of the product.
Internal surfaces of a system should not be painted. External
These solutions derive their fire-resistant qualities from the
surfaces shouldbeprotected byafully compatible coating, for
presence ofapproximately 45 ‘Z. ofwater. These fluidsaretrue
example epoxy phenolic or nylon-based, etc. The supplier
solutions and not emulsions as the categories previously
should be consulted on these matters.
described, i.e. HFAE and HFB.
Seals, hoses, packings and accumulator bladders shall be
They havegoodviscosity/temperature characteristics, andcan
manufactured from compatible materials such as fluoro-
be usedat lower temperatures than water-in-oil emulsions but
ela$tomers, PTFE and silicone rubber, Ethylene propylene and
have approximately the same upper temperature limits.
butyl elastomers may be suitable for some fluids, but the
Category HFC isdivided intoviscosity gra d es 15,22,32,46,68 supplier should beconsulted.
and 100.
7 Precautions to be taken when introducing
While they are acceptable lubricants, they provide for reduced
fatigue lifeofrollingcontact bearings. Anti-corrosive properties or using fire-resistant fluids
of fluids inthis category are generally good.
7.1 Oil-in-water emulsions (catagory HFAE)
While there are few material incompatibilities, the useofzinc,
cadmium, non-anodized aluminium and magnesium alloys
7.1.1 Compatibility with constructional units
shouldbeexamined priortotheiruse.The indiscriminate useof
and equipment
internal reservoir coatings and sealing materials isnot recom- &
mended.
7.1.1.1 Compatibility with elastomers
6.2.4 Synthetic fluids containing no water SeeIs, hoses, packings and accumulator bladders which are
(category HFD) compatible with mineral oils are generally suitable. Cork,
asbestosand packings manufactured from leather arenotcon-
NOTE– ISO6743-4designatesHFDfluidsas“syntheticfluidscon- sidered suitable (see8.7.3).
tainingnowater”;theyarealsoknownas“anhydroussyntheticfluids”
or“non-water-containingsyntheticfluids”.
7.1.2 Handling
This category of fire-resistant fluids is sub-divided into four
sub-categories distinguished bythe nature ofthesynthetic pro- 7.1.2.1 Storage
ducts. These sub-categories are designated asfollows:
As the emulsifiers contained in certain fluids are sensitive to
– HFDR: synthatic fluids containing no water and con- low temperatures, itisrecommended that the fluids bestored
sisting of phosphate esters. at temperatures higher than orat least equal to O“C.

4
—
IS 15178:2002
ISO 7745: 1989
7.1.2.2 Preparation of the mixture 7.2.1.2 Compatibility with elastomers
It ispreferable to usewater with alow content ofmineral salts Sealsr hoses, packings and accumulator bladders which are
in order to obtain a stable emulsion. However, where difficult compatible with mineral oils are generally suitable. Cork,
or hard waters have to be employed due to availability, it is asbestosand packings manufactured from leather arenot con-
necessary to select an emulsifying oil capable of coping with sidered suitable (see 8.7.3).
such. It isadvised that the fluid supplier be consulted for his
specific recommendations. 7.2.1.3 Filtration
Once the specific emulsifyingoil has been selected, no ad- HFB fluids tend to retain contaminant particles insuspension
ditional precautions need to be taken with automatic pro- and effective filtration isessential. Inlet strainers and pressure
portioning, apart from correct regulation of the oildelivery. filters should have maximum screen or pore opening sizes of
approximately 70 and 10 ~m respectively. Filters (strainers)
In the case of hand proportioning, the mixture shall be should have a nominal flow capacity approximately two to
established byadding theoilslowlytothewater, thefluidbeing three times the rated pump capacity; fluid viscosity, working
shaken. temperature, flow rates and permitted pressure drop shall be
taken into account. Metal filters, either wire mesh or sintered,
The indiscriminate incorporation of additional ingredients may are normally compatible with emulsions but paper filter
adversely affect the characteristics of the fluid. elements should beof aresin-impregnated type recommended
by the fluid and/or filter supplier. Earth filtration or felt
7.1.2.3 Use elements should be avoided.
The normal temperature of use ranges from +5to +50 ‘C. 7.2.2 Handling
Owing to their limited lubricating properties, fluids of this 7.2.2.1 Working temperatures
category are normally used for installations where only
marginal lubrication isrequired. The normal temperature of use ranges from +5 to +50 “C.
Most types of HFB fluids are recommended for usewithin the
NOTE – Increasingthe oil content of theseemulsionsdoesnot above range although low-temperature types which incor-
substantiallyimprovethelubricatingpowerofthemixture. porate glycol can be used as low as – 10‘C. Tank heating
should be avoided, but, if essential, the heeting surface shall
7.1.2.4 Precautions ino~eration not emit more than 3 W/cm2 otherwise the stability of the
emulsion may beaffected. Water-in-oil emulsions shall not be
The oilcontent shallremain constant within the limitsspecified stored at temperatures below O‘C.
by the emulsifying oilsupplier.
7.2.2.2 Precautions inoperation
Any fluid accidentally ejected from a hydraulic system shall
flow away normally and not accumulate, otherwise the riskof A check shall be kept on the water content of the fluid which

splitting the emulsion existsand the form ation of separated oil shallbe maintained within specified limitsto avoid a reduction
will provide aflammable layer of material. infire resistancequalitiesandtoprevent unacceptable changes
inthe fluid viscosity from occurring.
The check ontheoilcontent ofanemulsion inoperation canbe
undertaken byusingeitherlaboratory methods orbyanon-site It may be advisable insome installations to leave the fluid cir-
pocket refractometer. culating inthe hydraulic circuit during extended periods of in-
operation toavoid’stratification of the major phases, i.e. water
and oil.
7.1.2.5 Drained installations (storage)
7.3 Water polymer solutions (category HFC)
Special precautions shall be taken with equipment during
storage, owing tothe potential riskofcorrosion which may oc-
cur after draining. There are various methods of protection 7.3.1 Compatibility with constructional units
available, suchasthe useofananti-rust oilorthe incorporation and equipment
of special emulsions with additional corrosion inhibitors.
7.3.1.1 Compatibility with metals
7.2 Water-in-oil emulsions (category HFB) HFC fluidsarecompatible with most metals normally usedwith
mineral oils; however, the use of zinc, magnesium, non-
anodized aluminium and cadmium shall be examined prior to
7.2.1 Compatibility with constructional units
their use.
and equipment
7.3.1.2 Compatibility with elastomers
7.2.1.1 Compatibility with metals and alloys
Seals, hoses, packings and accumulator bladders which are
Most HFB fluidsarecompatible with metalsandalloysnormally compatible with mineral oils are genarally suitable. Cork,
usedwith mineral oils;however, the useofzinc, cadmium and asbestosand packings manufactured from leather are not con-
magnesium alloys shall be examined prior to their use. sidered suitable (see8.7.3).

5