इंटरनेट मानक

Disclosure to Promote the Right To Information

Whereas the Parliament of India has set out to provide a practical regime of right to
information for citizens to secure access to information under the control of public authorities,
in order to promote transparency and accountability in the working of every public authority,
and whereas the attached publication of the Bureau of Indian Standards is of particular interest
to the public, particularly disadvantaged communities and those engaged in the pursuit of
education and knowledge, the attached public safety standard is made available to promote the
timely dissemination of this information in an accurate manner to the public.

“जान1 का अ+धकार, जी1 का अ+धकार” “प0रा1 को छोड न' 5 तरफ”

Mazdoor Kisan Shakti Sangathan Jawaharlal Nehru
“The Right to Information, The Right to Live” “Step Out From the Old to the New”

IS 9798 (1995): Low Pressure Regulators for Use with

Liquefied Petroleum Gas (LPG) Mixtures [MED 16: Gas
Cylinders]

“!ान $ एक न' भारत का +नम-ण”

Satyanarayan Gangaram Pitroda
“Invent a New India Using Knowledge”

“!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता ह”

है”
ह
Bhartṛhari—Nītiśatakam
“Knowledge is such a treasure which cannot be stolen”
 IS 9798 : 1995
( Reaffirmed 2006 )

( rifymg;i-itwq
)
* Indian Standard
LOWPRESSUREREGULATORSFORUSE
WITHLIQUEFIEDPETROLEUMGAS(LPG).
MIXTURES- SPECIFICATION
( First Revision )

UDC 621-646-4

@ BIS 1995 \

BUREAU OF INBIAN STANDARDS

MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG
NEW DELHI 110002

May 1995 Price Group S

.
Gas Cylinders Sectional Committee, HMD 16

FOREWORD
This Indian Standard ( First Revision ) was adopted by the Bureau of Indian Standards, after the
draft finalized by the Gas Cylinders Sectional Committee had been approved by the Heavy
Mechanical Engineering Division Council.
While framing this standard consideration is given to the fact that the production of LPG would
be restricted to commercial butane/propane mixture having a ceiling vapour pressure ~of 1653 kPa
( 16.87 kgf/cme ) at 65°C.
With the introduction of IS 8737 ( Part 2 ) : 1978 ‘Valve fittings for use with liquefied petroleum
gas ( LPG ) cylinders of more than 5 litre capacity : Part 2 Valve fittings for newly manufactured
LPG cylinders’, it was felt that a design of pressure regulator for matching these valves is a
necessity.
This design would have an inbuilt arrangement wherein the regulator could be clicked-on the
valve without use of tools, first locking and seaiing the regulator on the valve outlet before the
gas flow is initiated. It would not be possible to disconnect the regulator until the cylinder valve
is closed.
With the above in view, this Indian Standard was first published in 1981. Since then many
suggestions were received for its improvement and with the result Amendments No.1 to 6 were
issued. This standard is revised to incorporate the amendments issued and the suggestions
received from time to time. This revision includes a new clause for soundness test for high
pressure side of the regulator and permits IS0 metric threads for the inlet connection. The
requirement for the filter has been modified.
Notwithstanding the requirements specified in this standard, any new design, materials and
methods of assembly giving at least equivalent results are acceptable. In the preparation of this
standard, full recognition has been given to the possibilities of improvement through ingenuity
of design.
In the preparation of this standard considerable assistance has been derived from the following
publications:
a) IS 4784 : 1968 Low pressure regulators for use with butane gas;
b) IS 4785 : 1968 Low pressure regulators for use with propane gas;
c) BS 3016 : 1983 Pressure regulators and automatic change-over devices for liquefied petro-
leum gases. British Standards Institution;
d) ANSI Z 22.18-1973 Standard for gas appliances pressure regulators. American National
Standard Institute;
e) UL 144 Standard for safety - Pressure regulators for liquefied petroleum gas. Underwriters
Laboratories, USA;
f) NF M88-765 March 1975 Fixed adjustment, low pressure, reducing valve for commercial
butane for domestic use - Construction, equipment tests. Association Francaise de
Normalisation; and
g) Various specifications, original and modified, now in use by several parties in India.
The quantities in this standard have been expressed in technical metric units. However, in view
of the introduction of International System ( SI ) units in the country, the relevant SI units and
corresponding conversion factors are given below for guidance:
1 kgf/cmP = 98066 5 kPa ( kilopascal ) = 10 m of Water column ( WC )
= 0.980 665 MPa ( megapascal )
= O-980 665 bar
1 Pa = 1 N/m*
For the purpose of deciding whether a particular requirement of this standard is complied with,
the final value, observed or calculated, expressing the result of a test or analysis, shall be rounded
off in accordance with IS 2 : 1960 ‘Rules for rounding off numerical values ( revi&)‘. The
number of significant places retained in the rounded off value should be the same as that _of the
specified value in this standard.
Pressures indicated in the various requirements/clauses of this standard are gauge presrwe unless
otherwise stated.
 IS 9798 : 1995

Indian Standard
LOW PRESSURE REGULATORS FOR USE
WITH LIQUEFIED PETROLEUM GAS ( LPG )
MiXTURES 7 SPECIFICATION
( First Revision )
-1 SCOPE 3.5 Nominal Outlet Pressure
This standard specifies materials, construction, The basic rated outlet pressure desirable in a
performance, and testing requirements for low regulator set at 50 percent rated capacity at a
pressure single or two stage regulators for use specific inlet pressure. The nominal outlet
with liquefied petroleum gas mixtures in vapour pressure rating for domestic regulator is 2,942
phase up to 4.903 kN/ms [ 50 gf/cm* or 500 mm kN/m2 ( 30 gf/cm* or 300 mm WC ).
water column ( WC ) ] outlet pressure.
3.6 Rated Capacity
NOTE - Low pressure is considered to be any pres-
sure below 6.894 kN/m* ( 70.3 gfjcms ). Domestic and The standard rated capacity for LPG regulators
commercial appliances normally operate at a gas For domestic use is up to 503 l/h of vapour. For
pressure of 2.942 kN/ma ( 30 gf/cm* or 300 mm water purpose other than domestic, higher capacity
column ).
regulators could be used. For purposes of perfor-
mance tests, the flows are stated in terms of
2 REFERENCES percentages of rated capacity, so as to cover all
The Indian Standards listed in Annex A are low pressure regulators whatever the rated
necessary adjuncts to this standard. capacity.
3.7 Single Stage Regulator
3 TERMINOLOGY
Regulator in which reduction of the inlet pres-
3.1 Commercial Butane sure down to the desired regulated outlet
pressure is achieved in one stage only.
A hydrocarbon product composed predomi-
nantly of butanes ( n and iso ), butyleoes or 3.8 Two Stage Regulators
their mixtures of maximum vapour pressure of
980 kPa ( 10 kgf/cm’ ). In this the inlet pressure is reduced to the
desired outlet pressure in two stages by an
3.2 Commercial Butane/Propane Mixture arrangement in the same regulator only. The first
stage regulation governs the reduction of inlet
A hydrocarbon product composed predomi- pressure to an intermediate pressure and the
nantly of a mixture of butanes ( n and iso ) second stage regulation governs the reduction of
and/or butylenes with propane, and/or propylene this intermediate pressure to the desired outlet
of maximum vapour pressure of 1 653 kPa pressure. Both stages may be incorporated in
( 16.87 kgf/cm* ). one body.

3.3 Commercial Propane 4 MATERIAL

A hydrocarbon product composed predomi- 4.1 All components parts shall be manufactured
nantly of propane, propylene or their mixtures from or be treated with materials compatible
of mrximum vap3uc pressure of 2 548 kPa with LPG as well as be unaffected by chemical
( 26 kgf/cm’ ). or thermal influences that may be encountered
normal Materials specified ’
3.4 Lock Up Pressure ;“s 319 : 1989 ylei10 * 1977 IS 742 * 1981 an’:
6912 : 1985 a;e recomdand& for thk manufac-
The outlet pressure of the regulator under ture of the regulators; but other type of
‘no-flow’ conditions, which shall be achieved materials may be used provided that the
within 60 seconds after cessation of flow, with standards of performance, durability and safety
the inlet pressure to the regulator remaining on. of the regulator are not lowered.

1
IS 9798 : 1995

4.1.1 Brass parts shall not be susceptible to performance readings are taken. The readings
season cracking. The susceptibility to season shall be within the accceptable limits of
cracking shall be determined by the method performance as given in 8.9.
given in IS 2305 : 1988. 4.4 Valve Pad Material
4.2 The body for all regulators of rated capacity Valve pad material shall be of synthetic rubber
up to 1 000 l/h shall be manufactured from or other material equally suitable for the
alloys of zinc and/or aluminum by pressure application and of a quality to satisfy the
die-casting. following minimum requirements.
4.3 Diaphragm Material 4.4.1 The valve pad material shall be free from
porosity, pits and foreign particles and shall
The material of diaphragm shall be of synthetic have a smooth non-tacky surface with minimum
rubber or other material equally suitable for talc or bloom. The material shall have low
the application and shall satisfy the following compression set, cold flow and creep
requirements. characteristics.
4.3.1 The material shall be free from porosity, 4.4.2 The materia1 shall, after immersion in
pits and foreign particles and shall have a pentane or commercial LPG for 72 hours, meet
smooth, non-tacky surface with minimum talc the appropriate requirements tabulated in
orbloom. Annex C. After this test. change in hardness
value from before to after th> test shall not
4.3.2 The material shall not show change of exceed 15 IRHD.
more than 10 IRHD when subjected to ageing
of 72 hour-s at 70°C in accordance with method NOTE - The tests at 4.4.1 and 4.4.2 are work batch
tests. On initial selection of valve pad material, it
prescribed in 3 or 4 of IS 3400 ( Part 4 ) : 1987. shall also be tested in commercial LPG in vapour
phase for 72 hours and shall not show any volume_
4.3.3 The material shall be capable of withstand- tric shrinkage or increase greater than 10 percent.
ing a clamping pressure of 490 kPa ( 5 kgf/ The loss of plasticizers or other ingredients due to
cm’ ) whereby the material itself or the extraction shali not exceed 5 percent by weight.
substance with which the ~fabric layer has been 4.4.3 The material shall not show change of
impregnated shall not be pressed away, flowed more than 10 IRHD when subjected to ageing of
away or be bruised or otherwise damaged. 72 hours at 70°C in accordance with the method
~‘-.!.“,.+.;h.Z.~
yLrJuLL”ru rrnJ_r
ULLULL 3 or 4 of TQ
~3 7AAl-l
JYVV \I rarl
n--r q* J\ i.
4.3.4 The material shall be such that when an
1987.
assembled regulator is subjected to the test as
specified in Annex B the diaphragm shall not 4.4.4 The valve pad fitted in its housing shall bc
pull out or burst at a pressure less than 275 kPa immersed in pentane or commercial LPG (see
( 2.8 kgf/cm2 ). Annex D ) in the vapour phase for 72 hours
after which the pad shall not show evidence of
4.3.5 The material shall, after immersion in being forced out of position due to swelling or
__.._ _
ot’ner c;aLlse.
pentane or comnierciai LPG for 72 hours, meet
the appropriate requirements tabulated in
Annex C. Change in hardness value, before and 5 CONSTRUCTION AND WORKMANSHIP
after the immersion shall not exceed 15 IRHD 5.1 A typical regulator to match self closing
1 see IS 3400 ( Part 2 ) : 1980 1. valve is shown in Fig. 1 for illustration purpose.
NOTE - The tests at 4.3.1 to 4.3.5 are work batch
tests. On initial selection of a diaphragm material, 5.2 The regulator, including all the component
it shall also be tested in commercial LPG in the parts, shall be mechanically strong, of sound
vapour phase for 72 hours, and shall not show a construction and of a high standard of work-
weight or volume change greater than 15 percent. manship and finish.
4.3.6 The material shall be such that the 5.3 The components of a regulator shall be
flexibility of the diaphragm shall not be interchangeable with the corresponding compo-
impaired after samples of the same have nents of any other regulator of the same model
recovered completely to ambient temperatures and size by the same manufacturer.
from cooling to -20°C or heating to 65°C. For
5.4 Screw Thread
these tests assembled regulators are cooled
to -20°C or heated to 65°C and maintained at Except for the screwed ends of regulators not
these temperatures for 10 minutes and then kept fitted with inlet or outlet connectors, screw
in atmosphere to recover completely to ambient threads shall comply with the requirements of
temperature of its own ( not by induced heating IS 554 : i985 or IS 2643 ( Part i ~j : i975 or
or cooling ). After recovery, the setting and IS 42~18( Parts 1 to 4 ) : 1976.

2
 SUITABLE LOCKING

ECCENTRIC

DIAPHRAGM

LINKAGE MECHANISM

HANDLE
----I
w

ATOR INLET
:T

STUB

.E RE TAINER

TING SPINOL E

CLAMPING MECHA& I
FIG. 1 DIAGRAMMATICSECTIONALILLUSTRATIONOFA PRESSUREREGULATORUSED WITH
SELFCLOSINGSPRINGLOADEDTYPE VALVE FOR LPG
IS 9798 : 1995

5.5 Inlet Connection inlet or outlet of regulator the following shall

Where screwed connections are not used, the apply:
inlet of the pressure regulator shall be cast a) SCREWED ENDS - Where inlet or outlet
integrally as an inseparable part of the body or connections are not fitted, the inlet and
so fixed which cannot be separated without outlet of a regulator fitted with screwed
damaging the body. The size and the profile of ends shall comply with the requirements
the inlet connection shall match the outlet end of IS 2643 ( Part 1 ) : 1975 and IS 2643
of the spring actuated self-closing valve of LPG (1;;;’ 2 ) : 1975 or IS 4218 ( Part 3 ) :
cylinder to achieve a leak-proof coupled joint
without use of tools or without use of a resilient
packing or washer or gasket as a part of the 8 INLET CONNECTORS - Where used,
any washer, connecto~r and nut of a
regulator. However, the use of a gasket or screwed inlet union shall comply with
packing in the inlet connection of the regulator the applicable ~mating dimensions of
shall be permitted so long as there is a leak- IS 8737 : 1995.
proof joint with the valve, without the help of
gasket or packing as a part of the regulator. 5.6 Outlet Connection
5.5.1 The inlet connection shall be designed to For regulators for domestic service the outlet
withstand a minimum hydrostatic pressure of nozzle shall be horizontal cast integrally
2 490 kPa ( 25.4 kgf/cme ) held for 2 minutes. with the body. The type shall be any of the
two mentioned in IS 5116 : 1985, which are
5.5.2 The inlet connection shall also be capable reproduced in Fig. 2A and 2B. The choice of
to withstand a minimum pneumatic pressure of type of outlet shall be as per the agreement
1666 I-Pa ( 17 kgf/ cm2 ) at ambient tempe- between the manufacturer and the purchaser.
rature. Minor modifications in shape to suit the standard
bore or tubing are permissible if agreed to
5.5.3 Where screwed connections are used for between the manufacturer and the purchaser.

2A Outlet for 6.4 mm Rubber Tubing

28 Outlet for 7 mm Rubber Tubing

All dimensions in millimetres.
FIG. 2 OUTLETS FOR RUBBER TUBING

4
 IS 9798 : 1995

5.7 Body the leakage rate does not exceed N x 4 mm3/s.

( The symbol ‘N’ indicates conversion to normal
5.7.1 The body and cover shall be strong temperature and pressure conditions, NTP that
enough to withstand the stress of connecting is 760 mm of Hg pressure and 0°C. )
the regulator to the cylinder valve or piping
installation and to withstand normal stress 6.2 The regulator shall be leak tight when tested
imposed by service conditions, without deve- pneumatically at a pressure of 0.490 kN/m*
loping leakage at joints, permanent deformation ( 5 gf/cma ) below twice the nominal outlet
or other damage which might impair the pressure when fitted with a relief valve or
serviceability of the regulator. 14.70 kN/ma ( 150 gf/cm2 ) when not fitted
5.7.2 After machining and before finishing with a relief valve, applied through the outlet
treatment ( for example, painting ) the body connection of a fully assembled regulators and
shall be pressure tested for porosity with gas held for a period of not less than 30 seconds and
or air at a pressure of not less than 98 kPa not more than 60 seconds, after stability has
( 1.0 kgf/cm* ). been achieved. To get stability, adequate time
is allowed between introduction of test medium
5.8 Vent and the start of observation, so that the inter-
The breather hole ( air vent above diaphragm nal parts have attained balanced positions.
space ) shall be of such a size and at such
location on the cover that: 6.3 Those parts of regulator which are normally
subjected to the full cylinder pressure shall be
a) it does not easily get clogged/blocked, leak tight at a minimum hydrostatic pressure of
b) the accidental entry of foreign matter is 2 490 kPa ( 25.4 kgf/cm’ ) for a period of 120
minimized, and seconds. To ensure that the hydrostatic pres-
c) it would be difficult for an instrument sure and medium extends only in and up to the
inserted through the air vent hole to high pressure sections, a pneumatic back pres-
reach the diaphragm. sure not exceeding 34.70 kN/m* ( 150 gf/cm* )
IS applied to the outlet connection of the regu-
5.9 Pressure Relief Valve lator before the start of the test and is kept on
throughout the test. Any change in this back
Where a pressure relief valve is incorporated in pressure shall be ignored for judging the result
the design, it shall be set to discharge at a of the test.
pressure not less than twice and not more than
three times the outlet pressure setting of the 6.4 Those parts of regulator which are normally
regulator. subjected to the full cylinder pressure shall also
NOTE - Provision of a threaded inset screened hole
be tested for soundness at a pressure of 1 666
may be provided as per agreement between purchaser kPa ( 17 kgf/cm2 ) for a period of not less than
and manufacturer, so that any discharge from the 30 seconds and not more than 60 seconds, after
relief valve may be led safely away. This is appli- stability has been achieved. To ensure that the
cable to low pressure regulators used for purposes pressure and medium extends only in and up to
other than domestic.
the high pressure sections, a pneumatic back
5.10 Valve Pad Fitting pressure not exceeding 14.70 kN/m3 ( 150 gf/cm2 )
is applied to the outlet connection of the
5.10.1 A valve pad ( resilient ) shall be so regulator before the start of the test and is kept
retained without use of adhesive that it cannot on through out the test. Any change in this
loosen or work out of position under service back pressure shall be ignored for judging the
conditions. result of the test.
5.10.2 The inlet orifice and valve pad of the
pressure regulator shall be protected by provi- 7 RANGE OF PRESSURE ADJUSTMENT
sion of a filter of suitable material compatible
with LPG, of appropriate size of perforations 7.1 The standard range of pressure adjustment,
that does not hamper flow of vapour, but is yet the range of inlet pressure and the range of
effective against ingress action of~contaminating outlet pressures is elaborated in 7.2 and 3.9.1.
agents in the gas. Any acceptable arrangement This does not preclude any specific requirement
meeting this requirement, as agreed between the deviating from the standard, as may be agreed
manufacturer and the purchaser is also permitted. to between the manufacturer and the purchaser,
provided the essentials of the standard ranges
6 SOUNDNESS are maintained.
6.1 A regulator shall be considered to be leak 7.2 The standard range of inlet pressure for
tight when tested in accordance with 6.2 and if domestic service regulators for use with LPG

5
1s 9798 : 1995

mixtures having vapour pressure up to 1 654 kPa 8.4 Outlet Pressure Measurement
( 16.87 kgf/cms ) at 65°C shall extend for pur-
poses of the performance tests. from 49 kPa For measurement of outlet or delivery pressures
of regulator a water-in-glass-tube-manometer
( 0.5 kgf/cms ) to 1 666 kPa ( 17 kgf/cms ).
shall be used. The pipe between the outlet of
8 SETTING AND PERFORMANCE the regulator and the outlet pressure gauge or
manometer shall be of the bore not less than
8.1 Test Gases the outlet of the regulator and of length not so
long as to create a significant pressure drop.
The performance tests shall be carried out using
air, after making due provision for a factor of 8.5 Flow measurements shall be carried out
conversion representing the flow of appropriate using a direct indicating flowmeter ( rota-
gas for which the regulator is designed, that is, meter ). Calibrated orifices may also be used.
butane, propane or mixture for the equivalent
vapour condition. 8.6 Inlet Pressure Deviation
During the tests for performance it may be
The volume conversion factors for certain gases -noted that there is a slight deviation of the inlet
are given below: pressure, especially at lower ranges, at varying
Multiply Flow By To Obtain Flow outlet flows of the regulator under test. The
inlet pressure should be readjusted appropriately
?f Of
when such deviation is experienced.
Air 0.707 Butane
l-290 Natural gas 8.7 Lock up shall be achieved within 60 seconds
after cessation of flow.
0.808 Propane
0.75 120 RVP Butane/ 8.8 Unless otherwise specified, performance tests
Propane mixture shall be carried out at ambient tempera-tures.
120 RVP Butane/ 1.333 -Air 8.9 Performance
Propane mixture
8.9.1 The regulator shall be set so that, with
Butane 1.414 Air inlet pressure ranging from 49 kPa (~0.5 kgf/cm2 )
I .826 Natural gas to 1 666 kPa ( 17 kgf/cmz ) on gas Bow rate of
1.140 Propane 10 to 100 percent of rated capacity, the delivery
Natural gas 0.775 Air pressure shall not be less than 2.206 kN/ma
( 22.5 gf/cmz or 225 m of WC ) and not more
0.547 Butane than 3.923 kNjms ( 40 gf/cms or 400 mm of WC ).
0.625 Propane Static ( lock up ) pressure shall not exceed 4.41
Propane 1.237 Air kN/ms ( 45 gf/cma or 450 mm of WC ).
0.874 Butane 8.9.2 A regulator shall not chatter or vibrate
1.598 Natural gas while being tested at any flow or inlet pressure
in the range prescribed for the performance
The above data serves as a guide also in cases tests or under condition simulating normal
where the percentage composition of consti- service. If chattering or vibration occurs when
tuents in an LPG mixture are known. using air or nitrogen or permitted medium, the
test shall be repeated using the gas, for which
8.2 Chatter the regulator is designed.
A regulator using the gas for which it is designed 8.10 The requirements of performance as given
shall not chatter or vibrate while being tested in8.9 shall also be satisfied before and after
for performance. subjecting the regulator to the tests specified in
NOTE - It is improper to induce chatter by striking
8.10.1, 8.10.2 and 8.10.3. Deviation in the initial
the regulator severely or by using an output far in setting, after these tests, is acceptable.
excess of the maximum rated capacity, conditions
which may induce vibrations of the internal compo- 8.10.1 Cycle Test
nents and give a false impression of chatter.
When assessing a new design, a type approval
8.3 Orientation test in accordance with Annex E shall be
carried out. A fully assembled regulator shall
A regulator when installed shall be capable of withstand a minimum of 100 000 cycles of
operating in all orientations. The standard opening and closing operations, after which it
performance tests shall be carried out with the shall be subjected to a soundness test as in 6.2,
regulator in its recommended orientation. 6.3, 6.4 and performance as in 8.9.

6
 IS 9798 : 1995

8.10.2 Low Temperature Test c) Hydrostatic test ( 5.5.1 ),

The regulator is exposed to a temperature of 4 Soundness test ( 6.4 ),
-20°C for a minimum period of 10 minutes for d Body ( 5.7.2 ), and
the complete assembled unit to attain this
temperature. It is then removed and left exposed f ) Low and high temperature test ( 8.10.2
to the atmosphere until the assembly returns to and 8.10.3 ).
ambient conditions, after which it is tested. The
method of carrying out the test is elaborated in 10.2 Routine Tests
Annex F.
The following shall be carried out as routine
8.f0.2.1 Heating shall not be applied to reach tests:
the ambient temperature.
a) Pneumatic test ( 5.5.2 ),
8.10.2.2 Care shall be taken to avoid intrusion
of fluid or moisture into the regulator assembly b) Soundness test ( 6.2 ),
during cooling and recovery. For this the outlet
c) Hydrostatic test ( 6.3 ),
nozzle, the inlet and -breather hole may be
plugged. d) Chatter ( 8.2 ), and
810.3 High Temperature Test e) Setting and performance test ( 8.9 ).
The regulator is exposed to a temperature of
65°C for a minimum period of 10 minutes for 11 MARKING
the complete assembled unit to attain this
temperature. It is then removed and left exposed 11.1 A regulator shall be clearly and perma-
to the atmosphere until the assembly returns to nently marked with the following:
ambient conditions, after which it is tested. The
method of carrying out the test is elaborated a>Manufacturer’s name or trade-mark;
in Annex F. b) Month and year of manufacture, for
example, 9/93 for September 1993;
8.10.3.1 Forced cooling shall not be applied to
reach the ambient temperature. Cl Rated capacity in m3/h of LPG;
8.10.3.2 Care shall be taken to avoid intrusion 4 Number of this standard; and
of fluid or moisture into the regulator assembly
during heating and cooling. For this the outlet 4 Any other markings agreed to between
nozzle, the inlet and breather hole may bc the purchaser and the manufacturer.
plugged.
11.2 BIS Certification Marking
9 SEALING
The regulators may also Abe marked with
9.1 After testing, the body and cover of each Standard Mark,
regulator shall be sealed to discourage inter-
ference with the internal mechanism as well as 11.2.1 The use of the Standard Mark is governed
the pressure setting. by the provisions of Bureau of Indian Standards
Act, 1986 and the Rules and Regulations made
9.1.1 The manner of sealing shall be as agreed
thereunder. The details of conditions under
to between the purchaser and the manufacturer.
which the licence for the use of Standard Mark
10 CLASSIFICATION OF TESTS may be granted to manufacturers or producers
may be obtained from the Bureau of Indian
10.1 Type Tests Standards.
The following shall constitute type tests out of
the various requirements: 11.3 The markings may be distributed over the
body, cover and sealing plate/cap as found
a) Diaphragm material ( 4.3 ), convenient and as agreed to between the
b) Valve pad material (4.4 ), purchaser and the manufacturer.
is 9798 : 1995

ANNEXA
( Clause 2 )
LIST OF REFERRED INDIAN STANDARDS
IS No. Title IS No. Title
319 : 1989 Free cutting brass, rods and 34yz&SPart 2 ) : Methods of test for vulcanized
sections (fourth revision ) rubbers : Part 2 Hardntra
(>rst revision )
410 : 1977 Cold rolled brass sheet, strip
and foil ( third revision ) 3400 ( Part 4 ) : Methods of test for vulcanized
554 : 1985 Dimensions for pipe threads 1987 rubbers : Part 4 Accelerated
where pressure tight joints are ageing ( second revision )
required on the threads ( third 4218 ( Parts 1 IS0 Metric screw threads
revision ) to 4) : 1976
742 : 1981 Zinc base alloy die castings 5116 : 1g85
( second revision ) General requirements for
domestic and commercial
2305 : 1988 Method for mecurous nitrate equipment for use with LPG
test for copper and copper (first revision )
alloys ( jirst revision ) 6912 : 1985 Copper and copper alloy for-
2643 ( Part 1 ) : Dimensions for pipe threads ging stock and forgings (first
1975 for fastening purposes : Part 1 revision )
Basic profile and dimensions 87?7 . 1g95
_ . Valve fittings for uac with
(first revision )
liquefied petroleumgas ( LPG )
2643 (-Part 2 ) : Dimensions for pipe threads cylinders of more than 5 litrr
1975 for fastening purposes : Part 2 water capacity - Specification
Tolerances (-first revision ) (first revision )

ANNEX B
( Clause 4.3.4 )
BURSTING AND PULL-OUT TEST OF DIAPHRAGM IN AN ASSEMBLED REGULATOR

B-l GENERAL is, as it would be supplied by the manufacturer

to a buyer ).
B-l.1 The test is designed to give a practical B-2 TEST RIG
results on an assembled regulator, and is
intended as simple check method which may B-2.1 The outlet of the assembled regulator is
be applied by the regulator manufacturer to connected to a supply of air or nitrogen.
diaphragm material which will usually have -B-2.2 h gauge is incorporated in the test rig
been previously tested by some other method between the air or nitrogen supply and the
( for example, Mullin’s test ) by the supplier. regulator to indicate the applied pressure.
B-l.2 The test takes the form of a simple B-3 TEST METHOD
application of pressure ( air or nitrogen IS
suitable ) through the outlet connection the The pressure is applied -at approximately 78 kPa
underside of the diaphragm mounted in a ( 0.8 kgf/cma ) per second up to the level speci-
regulator in the fully assembled condition ( that fied in4.3.4 and maintained for 120 recondr.

8
 IS 9798 : 1995

ANNEX C
( Clauses 4.3.5 and 4.4.2 )
IMMERSION TEST ( RESISTANCE TO HYDROCARBONS )
C-l GENERAL a) Percentage of test WI - W,
gas absorbed = w,, x 100, and
The test is designed to mevaluste the rubber b) Percentage of W, - Wz x loo
material vis-a-vis its resistance to hydrocarbons. matter extracted = w,

C-2 PROCEDURE C-3 The results of the above test shall be in

accordance with as given below:
Weigh the sample, W, prior to test. Immerse the
same in pentane or test gas ( as defined in Component Extractables, Absorbed,
Annex D ) maintained at a temperature of percent percent
20 & 5°C for 72 hours. Remove the sample and Diaphragm 10 10
expose it to atmosphere. After 5 minutes, weigh Valve pad 5
the sample WI. Next, let it stay exposed to Seal 20 $
atmosphere for 24 hours and reweigh W,, and NOTE -It is permitted to wipe clean the compo-
calculate the following: nent after removal from immersion.

ANNEX D
( Claus 4.4.4 )
TEST GAS COMPOSITION
D-1 The test gas is nominally 50 percent b) The total content of C, hydrocarbons
propane. In practice, this test gas shall conform shall not exceed one mol percent, and
to the following specification: c) The total content of C4 and higher hydro-
carbons shall not exceed 2 mols percent.
a) The total content of propane shall not be
less than 45 mols percent and not greater D-2 Alternatively commercial liquefied petro-
than 55 mols percent, leum gas ( LPG ) may be used as the test gas.

ANNEX E
( Clause 8.10.1 )
CYCLE TEST ( ENDURANCE TEST )
E-l The purpose of the test is to evaluate the ment of non-flexibles. The test should relate
quality of various flexibles, such as valve pad; only to themflexibles referred to above.
diaphragm and spring, vis-a& retention of
critical properties relevant to function, resis- E-2 The regulator is mounted on a valve
tance to deformation/degradation, loss of ( whose outlet matches with the inlet of the
flexibility under conditions of flexing and regulator ). The outlet of the regulator is
unflexing. This test does not purport to check connected to a system which will indicate flow
any mechanical requirements of the construc- or lack of it ( that is, a burner, flowmeter or
tion/assembly and should not be taken as orifice in parallel with a pressure indicating
representative of actual service conditions and device such as a manometer column ). Air/Gas is
could introduce improper parameters of assess- introduced into the regulator inlet at an
9
IS 9798 : 1995

appropriate pressure in such a manner that the conditions and achieving the same objectives,
diaphragm gels fully flexed and the valve pad is would be acceptable.
held on its seat for a minimum of one second,
after which the inlet is shut off and the air/gas is E-3 After completion of the test mentioned
vented via the outlet of the regulator to above ( see E-2 ), the regulator shall meet the
atmosphere. requirements of soundness test as in 6.2, hydro-
static test as in 6.3 and performance as in 8.9.4,
E-2.1 One example of a set-up to carry out this however, with the static ( lock-up ) pressure not
test is to install quick acting valves upstream exceeding 1~10 percent of that allowable in
and downstream of the regulator, wherein the relevant lock-up clause.
downstream valve exhausts to atmosphere. The
NOTE - If the tests are carried out using LPG
valves are connected to a suitable time switch vapour as test medium, sufficient precaution should
so that as one opens, the other closes; with a be ensured to vent the inflammable gas to environ-
complete cycle-time of approximately 5 seconds. ments where there should be no danger of fire.
Alternatively, the venting could be done via gas
E-2.2 Any other set-up producing equivalent burning devices.

ANNEX P
( Clauses 8.10.2 and 8.10.3 )
LOW TEMPERATURE AND HIGH TEMPERATURE TESTS
F-l LOW TEMPERATURE TEST ensuring that the sealed container is opened only
after the assembly attains ambient conditions.
F-l.1 A fully assembled regulator, set as in 8.9
is placed in a sealed container and this con- F-l.2 A fully assembled regulator set as in 8.9
tainer is immersed in a bath of any convenient is placed in a sealed container and this container
fluid ( namely, methanol or any suitable freezing is placed in a bath of water heated to a steady
mixture like salt + ice + calcium carbide ) cooled temperature of 65°C. It is kept immersed long
to a steady temperature of-20°C and maintai- enough for the complete assembly to attain 65‘C
ned at this temperature by some reliable means ( 10 minutes ) after which it is removed and
( by additions of dry ice ). It is kept immersed exposed to the atmosphere so that the assembly
long enough for the complete assembly to returns to ambient conditions. It is then tested
attain-20°C ( 10 minutes ) after which it is in accordance with 8.9 for performance.
removed and exposed to the atmosphere so that NOTE - Care should be taken to prevent the bath
the assembly returns to ambient conditions. It water from entering the assemblv. or of moisture
is then tested in accordance with 8.9 for forming inside. This may be avoided by ensuring
performance. that the sealed container is opened only after the
assembly attains ambient conditions. Also air shall
NOTE - Care should be taken to prevent the not be forced through the assembly in an attempt to
cooling fluid from entering the assembly or of accelerate _. cooling
c . as
. this .is. likely
. to * result
. in c
moisture condensing inside. This may be avoided by conaensatron or morsrure msrae tne assemory.

10
Bureau of Iodian Standards
BIS is a statutory institution established under the Bureau of Indian Standards Ad, 1986 to
promote harmonious de\eiopmeut of the activities of slandaldization, marking and quality
certification of goods and attending to connected matters in the country.

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in any form without the prior permlssion in writing of BIS. This does not preclude the free use,
in the course of implementing the standard., of necessary details~, such as symbols and sizes, type
or grade designations. Enquiries relating to copyright be addressed to the Director
( Publications ), BIS.

Revision of Indian Standards

Amendments are issued to standards as the need arises on the basis of comments. Standards
are also reviewed periodically; a standard along wit-h amendments is reaffirmed when such review
indicates that no changes are needed; if the review indicates that changes are needed, it is taken
up for revision. Users of Indian Standards should ascertain that they are in possession of the
latest amendments or edition by referring to the latest issue of ‘BIS Handbook’ and *Standards
Monthly Addition’.

Thir Indian Standard has been developed from Dot : No. HMD 16 ( 0273 ),

Amendments Issued Siace Publicatioo

Amend No. Date of Issue Text Affected

~-

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LUCKNOW. PATNA. THIRUVANANTHPURAM.

_ .-
 AMENDMENT NO. 1 FEBRUARY 1998
TO
IS 9798 : 1995 LOW PRESSURE REGULATORS FOR
USE WITH LIQUEFIED PETROLEUM GAS (LPG)
MIXTURES - SPECIFICATION
( First Revision )
(Page 5, clause 6.1) - Substitute ‘4 N mrn3/s ’for ‘N x 4 mm3/s’.
(Page 7: clause 10.1) - Substitute the following for the existing:
‘The following shall constitute type tests out ofthe various requirements:
a) Diaphragm material (4.3,
b) Valve pad material (4.4),
c) Hydrostatic test (6.3),
d) Body (5.72), and
e) Low and high temperature test (8.102 and 8.103).
(Page 7, clause IO.2 ) - Substitute the following for the existing:
‘The following shall be carried out as routine tests:
a) Pneumatic test (6.2 and 6.4),
b) Chatter and performance test (8.9),’
(Page 10, clause F-l.1 ) -Insert the following at the end:
‘F-2 HIGH TEMPERATURE TEST
(Page 10, &ruse F-l.2 ) - Substitute ‘F-2.1’ for ‘F-1.2’.

(HMD16)

Reprography Unit, BIS, New Delhi, India

 AMENDMENT NO. 2 MAY 2002 ~.-.
TO ~.-.
IS 9798:1995 LOW PRESSURE REGULATORS FOR
USE WITH LIQUEFIED PETROLEUM GAS (LPG)
MIXTURES — SPECIFICATION
(First Revzkion )

( Page 1, clause 1 ) — Substitute the following (excluding NOTE) for the

existing clause:
‘1 SCOPE
This standard specifies materials, construction, performance and testing
requirements for low pressure single or two-stage regulators and automatic
changeover devices for use with Ii uefied petroleum gas mixtures in vapour
%
phase up to 4.903 kN/m2 [50 gf/cm or 500 mm water column (WC)] outlet
pressure.’
( Page 1, clause 2 ) — Substitute the following for the existing clause:
2 REFERENCES
The Indian Standards listed below are necessary adjuncts to this standard. At the
time of publication, the editions indicated were valid. All standards are subject
to revision, and parties to agreements based on this standard are encouraged to
investigate the possibility of applying the most recent editions of the standards
indicated below:
IS No. Title

319: 1989 Free cytting brass, rods and sections ~ourtlz revision)
410:1977 Cold rolled brass sheet, strip and foil (third revision)
554:1999 Pipe threads where pressure-tight joints are made on the
threads — Dimensions, tolerances and designation ~ourth
revision )
742:1981 Zinc base alloy die castings ( second revision)
2643 : 1999 Pipe threads where pressure-tight joints are not made on the
threads — Dimensions, tolerances and designation ( second
revision )
Gr 2
1
Amend No. 2 to IS 9798:1995

IS No. Title
3400 (Part 2) : Methods of test for vulcanized rubbers : Part 2 Hardness
1!J95 (second revision)
3400 (Part 4) : Methods of test for vulcani~ rubbers : Part 4 Accelerated
ageing (second revision)
4218 (Part 1) : ISO general purpose metric screw threads : Part 1 Basic
2001 profiles (second revision)
4218 (Part 2) : ISO general purpose metric screw threads : Part 2 General
2001 plan (second revision)
4218 (Part 3) : ISO general purpose metric screw threads : Part 3 Basic
1999 dimensions (second revision)
4218 (Part 4) : 1S0 general purpose metric screw threads : Part 4 Selected
2001 sizes for screws, bolts and nuts (second revision)
5116:1996 Domestic and commercial equipment for use with LPG —
General requirements (third revision)
6912:1985 Copper and copper alloy forging stock and forgings (first
revision)
8737:1995 Valve fittings for use with liquefied petroleum gas (LPG)
cylinders of more than 5-litre “watercapacity – ‘Specification
~irst revision)
14962 (Part 1) : 1S0 general purpose metric screw threads – Tolerances : Part 1
2001 Principles and basic detail
14962 (Part 2) : 1S0 general purpose metric screw threads – Tolerances : Part 2
2001 Limits of sizes for internal and external screy threads –
Medium quality
14962 (Part 3) : 1S0 general purpose metric screw threads – Tolerances : Part 3
2001 Deviations for constructional screw threads
14962 (Part 4) 1S0 general purpose metric screw threads - Tolerances : Part 4
Limits of sizes for hot-dip galvanized external screw threads
to mate with internal screw threads tapped with tolerance
position H or G after galvanizing

2
. Amend No. 2 to IS 9798:1995 ---- ~...
i
Is No. Title

14962 (Part 5) : ISO general purpose metric screw threads – Tolerances : Patl 5
2001 Limits of sizes for internal screw threads to mate with hot-dip F“
~
galvanized external screw threads with maximum size of
tolerance position h before galvanizing
NOTE — Delete years specified against Indian Standards in the text.
.
( Page 1, clause 3.8) — Insert the following new clauses after 3.8:
3,9 Automatic Changeover Device
A device designed to ensure continuity of gas supply where a reserve gas supply
is brought into use automatically when the ‘service’ gas supply is exhausted.
This may or may not incorporate a second stage regulation.
NOTE – A typical automatic changeover device is illustrated in Fig. 1A on page 4.

3.9.1 Indicators
An indicator shall be fitted to show’ when the supply cylinder(s) or vessel(s) is
empty and the reserve supply is being used.
3.9.2 Non-return valve shall be fitted to the inlet of automatic changeover
devices to prevent possible discharge of gas when changing cylinders. The
arrangement shall be such that it cannot readily be disconnected from the
device when changing cylinders. When pressure tested against the direction of
flow, maximum leakage rates.. shall not exceed 4 N mrn3/s at standard
temperature and pressure. The test ~hall be carried out at the following
pressures:
a) at 0.350 kg/cm2 minimum pressure, and
b) at 20 kg/cm2 maximum pressure..,.
( Page 2, clause 4.3.2) – Insert the following Note at the end of the clause:
NOTE — For guidance purpose, comparison of Shore A and IRHD hardness are given
below:

Shore A 30 40 50 60 70 80 90 100

IRHD 28.9 39.5 50 60.5 70 80 89.5 100

3
 &
m
Amend No. 2 to IS 9798:1995

FIG. 1A TYPICALAUTOMATIC CHANGEOVER DEVICE

4
 Amend No. 2 to IS 9798:1995
+
( Page 2, clause 5.4 ) — Substitute the following for the existing:
‘5.4 Screw Thread
Except for the screw ends of regulators not fitted with inlet or outlet
connectors, screw threads shall comply with the requirements of IS 554 or
IS 2643 or IS 4218 ( Parts 1 to 4 ) or IS 14962( Parts 1 to 5 ).’
( Page 4, clause 5.5.1 ) — Substitute the following for the existing:

5.5.1 The inlet connection shall be designed to withstand a minimum

hydrostatic pressure of 1.5 times the saturated vapour pressure of the gas at
65°C subject to a minimum of 18 kgfYcm2for 120s.
( Page 4, clause 5.5.3) — Substitute the following for the existing:
‘5.5.3 Where screwed connections are used for inlet or outlet of regulator or
cylinder changeover devices, the following shall apply:’ t
( Page 5, clause 6.3, j%st sentence ) — Substitute the following for the
existing sentence:
Those parts of regulator which are normatly subjected to the full cylinder pressure
shall be leak-tight at a minimum hydrostatic pressure of 1.5 times the saturated
vapour pressure of the gas at 65°C subject to a minimum of 18 kgf/cm2 for 120s.
( Page 5, clause 7.2) — Substitute the following for the existing:
7.2 For the performance test of the domestic service regulators the standard
range of inlet pressures for use with commercial butane, commercial
butane/propane mixture and commercial propane shall be as per Table 1.
Table 1 Performanq Teat
(Clauses 7.2 and 8.9.1)
Regulators for Gas Pnlet Preaaure Flow in% of Rated I@qge of Outlet
kgflcmz Capacity Pressure in nun of W.C.

Commercial Butane 0.5-17 100-1o 225400

17.0 0 450 Max
Commercial Butane- 0.5-17 100-10 22s-400
Propane Mixture 17.0 0 450 Max
Commercial Propane 0.5-20 100-10 225450
20.0 0 500Max

i
 ,

k..~.,—
Amend No. 2 to IS 9798:1995

( Page 6, clause 8.9.1 ) — Substitute the following for the existing:

.
.

-.
‘.,

‘8.9.1 The regulators shall be set as given in Table 1.’

( Page 7, clause 11.1) — Substitute the following for the existing:
‘11.1 A regulator shall be clearly and perrpanently marked with the following:
a) Manufacturer’s name w trade-marh
b) Month and year of manufacture, for example, 12/01 for December 2001;
-r-
c) Rated capacity in m3ih of gas designed for;
d) Number of this standard;
e) Any other markings agreed to between the purchaser and the manufacturer;
and
f) Name of gas, designed for.’

(ME 16) 1
t

Reprography Unit, BIS, New Delhi, India

 . .

AMENDMENT
NO. 3 MAY 2003
TO
IS 9798:1995 LOW PRESSURE REGULATORS FOR
USE WITH LIQUEFIED PETROLEUM GAS (LPG)
MIXTURES — SPECIFICATION
( First Revision)

{ Page 1, clause 2 ( see afso Amendment No. 2 ) ] — Insert the following at

appropriate place:
‘IS 6009:1970 Method for evaluation of results of accelerated corrosion test
IS 9844:1981 Specification for methods of testing resistance of electroplated
and anodized aluminiumcoatings by neutral salt spray test’
( Page 2, clause 4.2) — Insert the following new clause after 4.2:
4.2.1 Finish
The body and the cover of the regulator shall be electroplated or chemically
treated (surface passivated) and painted or powder coated so as to resist the
effect of atmospheric conditions to which the pressure regulator is exposed
during its working life. The type of finish shall be as agreed to between the
manufacturer.and the customer.
The surface finished components shall be subjected to test for corrosion
resistance as per IS 9844. The criteria of acceptance after the test shall be the
rating number as given in 6 of 1S-6009.

The painted or powder coated surfaces shall be tested for adhesion of paint by
the method described in Annex G.
( Page 2, clause 4.4.4) — Insert the following new clause after 4.4.4:
‘4.5 Seals, O-rings and rubber components -other than diaphragm and valve pad
shall withstand the requirement as laid down in 4.4.1 to 4.4.3.
NOTE — Rubber materials which are coming in contact with LPO shall lx tested.’

1
Amend No. 3 to IS 9798:1995

( Page 10, Annex F ) — Insert the following Annex G after Annex F:

ANNEX G
( Clause 4.2.1)
METHOD OF TEST FOR ADHESION OF PAINT
A square measuring 12 to 15 mm sides shall be marked on plain surface (not
having raised or sunk markings) of randomly selected specimen from the lot of
painted or powder quoted components. Cross lines at a distance of 1 to 1.5 mm
and inched at approximate y 120° angle with each other shall be described over
the marked portion with a pointed sharp instrument. A ce}lulose tape shall be
applied over this portion and left for 2 min after which it shall be jerked free
from the surface. If more than 3 percent of the squares are ripped away from the
surface under test and are adhering to this tape, the specimen shall be deemed to
have failed the test.

(ME 16)

ReprographyUnit,BIS,NewDelhi,India
2