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1 +, 1 + 01 ' 5
Mazdoor Kisan Shakti Sangathan Jawaharlal Nehru
The Right to Information, The Right to Live Step Out From the Old to the New

IS 13095 (1991): Butterfly valves for general purposes [MED

17: Chemical Engineering Plants and Related Equipment]

! $ ' +-
Satyanarayan Gangaram Pitroda
Invent a New India Using Knowledge

! > 0 B


BharthariNtiatakam
Knowledge is such a treasure which cannot be stolen
 IS 13095 : 1991
(Reaffirmed 2003)

Indian Standard
BUTTERFLY VALVES FOR GENERAL
PURPOSES
(First Reprint JUNE 19% )

UDC 621.646.25 : 669*13/*14

@I BIS 1991

BUREAU OF INDIAN STANDARDS

MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MAR0
- <
NEW DELHI 110002

September 1991 Price Group 4

Chemical Engineering Plants and Related EquipmerIt Sectional Committee, HMD 17

FOREWORD

This Indian Standard was adopted by the Bureau of Indian Standards, after the draft finalized by the
Chemical Engineering Plants and Related Equipment Sectional Committee had been approved by the
Heavy Mechanical Engineering Division Council.

The satisfactory performance of any valve depends on design, manufacture, correct installation and main-
tenance. This standard specifies the requirements for design and manufacture but not installation or
maintenance.

Particular requirements should be indicated by the purchaser in his purchase order or enquiry.

In the preparation of this standard assistance has been derived from BS 5155 : 198+ Specification for
butterfly valves issued by British Standards Institution ( BSI ).

For the purpose of deciding whether a particular requirement of this standard is complied with, the final
value, observed or calculated, expressing the result ol a test or analysis, shall be rounded off in accordance
with IS 2 : 1960 Rules for rounding off numerical values ( reuised ). The number of significant places
retained in the rounded off value should be the same as that of the specified value in this standard.
 Indian Standard
BUTTERFLY VALVES FOR GENERAL
PURPOSES
1 SCOPE lug type, U-section or flangeless type as shown in
Fig. 2, 3, 4, 5 and 6.
1.1 This standard covers double flanged and
wafer type of metal seated, resilient seated cast
iron, ductile iron and carbon steel and lined
butterfly valves for general purposes. Valves
covered under this standard are manually,
pneumatically, hydraulically or electrically ope-
rated.
1.2 It covprs valves of nominal pressure designa-
tions up to and including 4 MPa and Class 300 FJG. 2 BUTTBRFLYVALVB, SINGLE FLANGE
with ends flanged in accordance with appropriate WAFER TYPE
tables of IS 6418 : 1971 Cast iron and malleable
cast iron flanges for general engineering purposes
or wafer type valves with bodies designed to be
accommodated between pipe work flanges in
accordance with appropriate tables of IS 6418 :
1971 or IS 6392 : 1971 Steel pipe flanges in
nominal sizes DN 40 to DN 2000. It also covers
valves up to class 300 and flanges as per the FIG. 3 WAFBR LUGGED SCREW
pressure/temperature ratings given in IS 13159
( Part 1 ) : 1991 Steel pipe flanges and flanged
fittings : Part 1 Dimensions and IS 6418 : 1971
Cast iron and malleable cast iron flanges for
general engineering purposes.
2 REFERENCE
The Indian Standards listed in Annex A are FIG. 4 WAPER LUGGED THROUGH BOLT
necessary adjuncts to this standard.
3 TERMINOLOGY AND DEFINITIONS
Terminology and definitions covered in IS 4854
( Part 3 ) : !974 are generally applicable.
4 VALVE END CONNECTIONS
4.1 Double Flanged Valves
A valve having flanged ends for connection to FIG. 5 BUTTBRFLYVALVB, FLANGBLBSS
pipe flanges by individual bolting as shown in
Fig. 1.
4.2 Wafer Valve
A valve for clamping between two pipe flanges
using through bolting, This may be single flange,

FIG. 6 BUTTBRFLYVALVB, U.SECTION

WhPBR TYPE
NOTE - This type of valve may be suitable for the
individual bolting of each flange to the pipe work, but
FIG. 1 BUTTBRFLYVALVE, DOUBLE this may not be assumed.
FLANGED TYPE ( These figures are illustrative only ).
 -1s 13095 Y l!m

5 SERVICE APPLICATIONS in Annex B. Flanges as per any other specific

requirements of the purchaser may also be given
5.1 Valves shall be suitable for one or more of the
as agreed to bttween the manufacturer and the
following applications:
purchaser or as per IS 13159 ( Part 1) : 1991.
a) Tightshut off - A valve having no visi-
ble leakage past the disc 9.1.1 Flanges shall be at right angles to the axis of
in closed position under the bore and concentric with the bore. Flanges
teat conditions. shall be drilled unless otherwise specified and bolt
b) Regulating - A valve intended for holes shall be off centres. Tapped holes in the
regulating purposes and flanges may be used when required by the design
which may have a clea- of the valve.
rance between the disc
and the body in close 9.2 Wafer Body Enda
position.
9.2.1 Body ends shall be capable of being fitted
c) Low leakage - A valve which has speci- between the pipe flanges complying with the
fied maximum leakage requirements of Annex B flange drilling.
rate past the disc in the
closed position. 9.2.2 The joint faces shall be at right angles to
the axis of the bore and concentric with the bore.
5.2 Vacuum Condition
Where valves are to be used under vacuum 9.2.3 Holes may be provided, where required by
conditions, purchaser shall mention specilically the design, for the passage of the bolts securing
and the detailed design provision shall be mutu- the flanges and the valve. Where through bolting
ally agreed between the purchaser and the manu- is not particable due to the presence of valve shaft,
facturer. bearing housing, tapped holes may be provided
for individual bolting of each flange.
6 NOMINAL SIZES

The range of nominal valve size ( DN ) in mm 10 FACE TO FACE DIMENSIONS

shall be as follows:
10.1 Face to face dimensions of double Aanged
40, 50, 65, 80, 100, 125, 150, 200, 250, 300, 350,
and wafer types of valve shall be as per Table 1.
400, 450, 500, 600, 700, 800, 900, 1000, 1 200,
1400, 1600, 1800 and 2 000.
10.2 Face to face dimensions given in Table 1
7 NOMINAL PRESSURES are exclusive of the sealing gaskets at both ends.

7.1 Valves shall be designated by nominal pres- 10.3 The manufacturer shall ensure that adequate
sure ( PN ) defined as the maximum permissible space will be available between valve flanges for
working pressure ( MPa ) at 20C temperature as bolting when flanged valve with short body face
follows: to face or wafer long face to face are manu-
factured.
PN 0.25, PN 0.6, PN 1.0, PN 2.5 and PN 4.0
10.4 Tolerance on face to face dimensions in
7.2 The class designations for valves specified by
Table 1 shall be as follows:
nominal pipe sixes shall be class 125, class 150
and class 300.
Face to Face Dimensions oj Tolerance
Unlined Valve
8 PRESSURE/TEMPERATURE RATINGS
mm mm
T___-__h,__-_~
Maximum permissible gauge working pressure and
Over Up to and
operating temperatures shall be in accordance
Including
with IS 6418 : 1971 and IS 13159 ( Part 1 ) :
1991 except that restrictions on temperature may 0 250 zt2
be placed by the manufacturer on valves in 250 500 zt3
accordance with this standard by reason of valve
500 800 f4
type, trim materials or other factors. However, all
valves shall be suitable for continuous use at their 800 1 000 zt5
PN designation within the temperature range of 1 000 2 400 &6
- 1OC to 65C.
9 BODY ENDS 11 BODIES

9.1 Double Flanged Body Endm Body end ports shall be circular and the numeri-
The dimensions of flanged body ends and drillings cal values of the diameter shall be as close as
. shall be in accordance with the requirement given possible to the value of DN.

2
 Table 1 Face to Face Dimensions
( Clauses 10.1 to 10.3 )

All dimensions in millimetres.

Nominal Doable Flaw Double Flan- Wafer Short Wafer Wafer Wafer
Size ged Long Medium Long
I-- ged Short
_I
Face-to-face dimensions for Face-to-face dimensions for nominal pressure
nominal pressure not exceeding not exceeding
- - --

-1
PN 25
If
PN 25 PN 40 PN 2.5 PN 25 PN 40
Class 125/:50 Class 300 Class 125/150 Class 150 Class 125/150 Class 300
- -
T
4 5 6 7
- - -I
DN mm mm mm mm mm mm

40 106 140 33 - - -
50 108 150 43 - - -
65 112 170 46 - -. -
80 114 180 46 - 64 49
100 127 190 52 - 64 56
125 140 200 56 - 70 64
150 140 210 56 - 76 70
200 152 230 60 - 89 71
250 165 250 68 - 114 76
300 178 270 78 - 114 83
350 190 290 - 92 127 127
400 216 310 - 102 140 140
450 222 330 - 114 152 160
500 229 350 - 127 152 170
600 267 390 - 154 178 200
700 292 430 - 229 -
800 318 470 - - 241 -
900 330 510 - - 241 -
1 000 410 550 - 300 -
1 200 470 630 - - 350 -
1 400 530 710 - - 390
1 600 600 790 - - 440
I 800 670 870 - - 490 -
2 000 760 950
- - - 540 -

NOTE - Wafer type valves may not be available in all combinations of materials and face-to-face dimensions.

I2 DISC AND SHAFT IS SEATING AND LININGS

The disc and shaft shall be designed to withstand Non-integral seatings, and lining where used, and
the maximum pressure differential across the their means of attachment shall be such as to
valve in either direction of flow. The shaft may preclude their becoming loose in service.
be of one piece design or in two pieces separately
I4 BEARINGS
attached to the disc. Any means of attachment
between the shaft and the disc shall be such as 14.1 The bearings shall be suitable for the maxi-
to preclude components becoming loose in mum loads imposed by the shaft during testing
service. and in service.

3
IS 13095 : 1991

14.2 For valves DN 350 and above, a bearing shall 15 MATERIALS

be provided to take the axial thrust, spring
This standard is based on materials specified in
retaining clips ( circlips ) shall not be used as
Table 2. Unless otherwise agreed, the mateiials
thrust bearing.
shall be of a grade equivalent to those given in
14.3 Suitable sealing shall be provided for the Table 2 or superior. Other material may be used
shaft where it passes outside the pressure contain- as per agreement between the manufacturer and
ing enclosure. the purchaser.

Table 2 Basic Materials

Component Material IS Referred Grade

Body Cast iron 210 : 1978 FG 200, Min

Spheroidal graphite iron 1865 : 1974 SG 400112
Carbon steel 2004 : 1978 Cl. 2 or Cl. 3
1875: 1978 Cl. 2 or Cl. 3
2856 : 1987 Gr 1 or Gr 2

Disc Cast iron 210 : 1978 FG 200, Min

Spheroidal graphite iron 1865 : 1974 SG 400/12
Carbon steel 2004 : 1978 Cl. 2 or Cl. 3
1875 : 1978 Cl. 2 or Cl. 3
2856 : 1987 Gr 1 or Gr 2
Stainless steel 3444 : 1987 Gr 6 or Gr 7
Gun metal 318 : 1987 Gr - LTB, or
LTB,
Aluminium bronze 305 : 1981 Gr 2
_
Shaft Stainless steel 6603 : 1972 12 Cr 13
15 Cr 16 Ni 2
04 Cr 18 Ni 10
04 Cr 17 Ni 12 MO 2
Carbon steel 1570 ( Part 2 ) : 1979 40 C8
Aluminium bronze 305 : 1981 Gr 2
Nickel copper alloy

Seating ring/ Stainless steel 6603 : 1972 04 Cr 18 Ni 10

Seal retaining ring 04 Cr 17 Ni 12 MO 2
3444 : 1987 Gr 2, Gr 6 or Gr 7
Gun metal 318 : 1981 Gr LTB, or LTBs
Aluminium bronze 305 : 1981 Gr 2
Deposited metal-suitable for
duty or resilient material
( seeNote )
-.-_
Seat Elastomers - Nitrile, Neoprene,
E. P. D. XI. Rubber
---
Shaft bearing Manufacturers standards; - -
seals Suitable for duty

Internal fastenings Stainless steel Manufacturers Suitable for dur\

standard
_-- -
Lxternal bolting Carbon steel; tensile - -
strength 390 N/mm or
MPa
-
SOTE - When the resilient seals forms parts of:
a) the body and the disc is made of grey cast iron, spheroidal graphite iron, or carbon steel II IS rt~cc~rnrnrr~d~~~l
that the disr should be provided with a disc facing, deposit on the edge, or roatrd all over.
1,) the disc and the body is madr of grey cast iron, spheroidal graphite iron or rarhon Etvel 11 I:, ret ~~rnmelldvd
that tbe body should br provided with a facing rmg, deposit on diameter III contract MII~ rt.slllvut \c.~I (jr
coated a11 over.

4
 IS 13095 : 1991

16 OPERATION 16.5.3 Rod seals and piston caps shall be of nitrile

rubber or other material equally suitable for
16.1 Manual Operation hydraulic service.
All valves shall be capable of being operated at a 16.6 Pneumatic Operators
differential pressure across the disc as marked on
the valve. Lever, worm gearltravelling nut type 16.6.1 With cylinder operation, pressure shall be
or any other suitable type of operator can be maintained on the cyclinder piston at each end
used. of its stroke unless other means are provided to
prevent drifting.
16.1.1 Direction
16.6.2 Cylinders shall be equipped with a dirt
Unless otherwise specified, manually operated wiper to clean the piston rod before it enters the
valves shall be closed by turning handwheel or cylinder. Alternatively cylinder with its linkage
iever in a clockwise direction when facing the should be housed in weather-proof enclosure.
handwheel or lever. The design of lever when
fitted shall be such that the lever may only be 16;6.3 Rod seals, rod wiper and piston caps shall
assembled to the valve so that it is parallel to the be of neoprene, nitrile rubber or equivalent
direction of flow when the valve is open. material suitable for air service,
16.6.4 Cylinders shall be equipped with adjust-
16.1.2 Al] gear travelling nut operators shall be
able cushions at each end of the stroke, if so
provided with suitable stops to prevent movement
specified.
of the shaft beyond the limit correspnding to the
fully closed position of the disc. 17 TESTING

16.1.3 All gear/travelling nut operators shall be All valves shall be hydrostatically tested by the
packed with grease for life time operation. Gear/ manufacturer before despatch. The pressure shall
travelling nut operators shall be totally enclosed be obtained without any significant hydraulic
and whether proof for general application. For shock. Testing shall be carried on before applica-
special applications such as marine, submerged tion of paint or other similar treatment unless
service, buried service etc. the purchaser may otherwise agreed between the purchaser and the
specify special enclosure. manufacturer. There shall be no air entrapped
within the part of the valves subjected to test
16.1.4 All gearltravelling nut operators shall be pressure.
self locking type. AI1 lever operated valve shall be
capable of being locked at at least three inter- 17.1 Performance Testing
mediate positions. Each valve shall be shop operated from fully
16.2 The operating handwheels shall be marked closed to fully open position and reverse, under no
CLOSE or SHUT to indicate the direction of pressure and no flow condition to demonstrate
closure. that the complete assembly is workable.

16.3 The operator ahall be provided with arrange- 17.2 Body Test
ment to indicate the disc position.
Completely assembled valve shall be tested as
16.4 Electric Operators follows:

16.4.1 Electric motor drives shall be equipped The body ends shall be blanked so that the
with limit switches and torque switches for both valve is subjected to the full pressure in all
open and closed positions. directions induced by the test pressure wafer
16.4.2 Any gearing in direct association with elec- valves may be tested in any suitable manner
tric motor drive shall be totally enclosed and shall agreed between the purchaser and the manu-
operate in a lubricant. facturer. The valve disc shall be in slightly
open position and pressure equivalent to 1.5
16.4.3 Each electric operator shall be provided times the maximum permissible working pres-
with an auxiliary handwheel for manual operation. sure shall be applied with water. The duration
of this test shall be as in Table 3.
16.5 Hydraulic Operators
16.5.1 With cylinder operation, pressure shall be 17.3 Seat Test
maintained on cylinder piston at each end of its
stroke unless other means are provided to prevent The seating surface of the valve shall he cleaned
drifting. unless a surface treatment forms an integral part
of the design or the use of a temporary surface
16.5.2 Cylinders shall be equipped with dirt wiper treatment has been agreed between the manufac-
to clean the piston rod befbre it enters the turer and the purchaser to avoid the possibility of
cylinder. damage under the conditions of the test.

F
 .

I8 19995 i 1991

Table 3 Test Durations this standard and stating the actual pressures and
medium used in the test.
( Claue~ 17.2, 17.3 and 17.4 )
Table 4 Leakage Rates

Mimimum Test Duration ( Clause 17.5 )

Nominal Dia
I
I
in Minutes for I
I
Body Test Seat Test
mm
I When Applicable Valve Type Leakage Rate

Up toand including 56 0.25 025 No visible leakage for

Tight shut-off
65 to 150 1 1 I duration of test

200 to 300 2 2 Low leakage 01 mms/s x DN ( scu 5 )

350 to 1006 5 2 Not specified. Outside the

Regulating
I scope of this standard
1200 to 2 000 5 3

NOTE - During the body teat, there rhall be no leak _ NOTE - Applicable to sizes DN 40 to DN 1200 only.
age through the metal end joints or the valve shaft real, Leakage rates for larger sizes are outside the scope of
nor shall any part be permanently deformed. this standard.

17.3.1 Each valve shall be shop tested for leaks 19 INSPECTION

in closed position. The test shall be conducted
If inspection is required, this shall be stated in
with the body flanges in a horizontal position.
the enquiry/order. The purchaser or his authori-
Pressure shall be applied to the upstream end of
sed representative shall have access to the manu-
the valve, the downstream being open to atmos-
facturers works at all reasonable times to inspect
phere. The duration of test shall be as per Table
assembled valve to his order.
3. There shall be no indication of leakage past the
valve disc during test and valves shall be drop 20 WITNESSING OF TESTS
tight. Seat test shall be carried out in both the
directions of valve if agreed between the manu- Whan the purchaser desires to witness the tests,
facturer and the purchaser. The seat test pressure this shall be specifically agreed in advance.
applied on upstream side shall be equivalent to l-1 21 MARKXNG
times the maximum permissible working pressure
at 20C and shall be applied with water. Marking shall be cast integral on the body or. on
17.3.2 For regulating type valves seat test shall a plate securely attached to the body. The mark-
not be applicable. ings shall be in accordance with IS 9866 : 1981.

17.4 Disc Strength Test 22 PREPARATION FOR DESPATCH

The test shall be conducted with the body flanges 4 Valve shall be complete in all respect when
in horizontal position. The test pressure shall be shipped. Each valve shall be drained,
1.5 times the maximum permissible pressure at cleaned, prepared and suitably protected
20C. With disc in closed position, hydrotest pres- with 2 coats of red oxide on unmachined
sure shall be applied to the lower face of the disc surfaces and rust preventive coats on
for duration as per Table 3. There shall be no machined and flanged surfaces for despatch
damage to the valve disc nor any part of valve or in such a way as to minimise the possibility
disc shall be permanently deformed by the test. of damage and deterioration during transit
The purpose of this test is to provide evidence of and storage. Painting other than specified
the adequacy and structural integrity of disc and on the finished valve shall be as per the
body. Any leakage past the seat shall not be the agreement between the manufacturer and
criteria for rejection of the valve ( Sampling test the purchaser.
sample as per IS 2500 ). For regulating type b) Disc shall be unseated when despatched,
valves, disc strength shall not be applicable. but care shall be taken to ensure that there
17.5 Maximum permissible leakage shall be as is no risk of damage to the disc.
given in Table 4. 4 When specified, the body ends shall be
suitably sealed to exclude foreign matter
18 TEST CERTIFICATES during transit and storage.
When specitied by the purchaser, the manufac- 4 Components shipped unattached shall be
turer shall issue a test certificate confirming that adequately protected and iden tifed to
the valves have been tested in accordance with permit correct field assembly.

6
 IS 13o!l5 t 1981

-23 lNFORMATION TO BE FURNISHED BY iii) Low leakage rate

THE PURCHASER IN AN ORDER OR
.ENQUIRY iv) Suitability for flow in both directions

1) General requirements 3) Mode of operation

9 Size of the valve . . . . . . .. . . . mm
i) Manual with fever or handwheel or
ii) Quantity chainwheel
iii) Fluid handled ii) Power/voltage/frequency/No. of phases/
air supply pressure/type of operator
iv) Maximum working . . . _ . . . --. MPa
pressure
iii) Direction of rotation of handwheel
v) Design pressure . . . .. . . . . . . . MPa
iv) Orientation of handwheelllever with
vi) Maximum differen- . . . . . . . . . .. . MPa reference to pipeline
tial pressure ( when
valve shut ) 4) 7-e of construction
vii) Maximum flow . . . __.. . . . ..ms/ h and
i) Flanged or wafer [ lug wafer single/
corresponding pre-
wafer flangejflangeless wafer/U-section
ssure...MPa
wafer J
viii) Normal flow .. . ... ... ... ma/h
ii) Face to face dimension ( short or long
ix) Temnerature of . . . .-. .. . . . . K series )
fluid *
iii) Flange specification
4 Maximum allow- . . . . . . . . . . . .MWC
able pressure drop ( meters of water iv) Whether lifting lugs and mounting feet
column ) are required

xi) Operating time ... ... ... ... S v) Valve installation - whether horizontal
( for power ope- or vertical shaft
rated valves )
5) Special requirements like spool pieces,
2) Service floor stands, etc.
i) Tight shut off Any other information not covered in the
6)
ii) Regulation above sections.

ANNEX A
( Clause 2 )

LIST OF REFERRED INDIAN STANDARDS

IS No. Title IS Ail. Title

210 : 1978 Grey iron castings ( third 1875 : 1978 Carbon steel billets, blooms,
w&on ) slabs and bars for forgings
(fourth rtiion )
305 : 1981 Alumiaium bronze ingots and
castings ( second revision ) 2004 : 1978 Carbon steel forgings for gene-
ral engineering purposes ( second
318 : 1981 Leaded tin bronze ingots and revision )
castings ( second revision )
2500 Sampling inspection tables:
1570 Schedules for wrought steels: ( Part 1 ) : 1973 Part 1 Inspection by attri-
( Part 2 ) : 1979 Part 2 Carbon steel ( Unallo- butes and by count of defectr
yed steels ) (&St revision)
%
1865 : 1974 Iron castings with spheroidal or 2500 Sampling inspection tables:
nodular graphite ( second (Part 2 ) : 1065 Part 2 Inspection by variables
revision ) for percent defective

1
4 c

. .

I&15095:1991

IS x0. Title IS Jb. Title

2856 : 1987 Garbon steel castings for pres- 4854 Glossary of terms for valves and
aure comaing parts suitable for ( Part 3 ) : 1974 their parts: Part 3 Butteryfly
high temperature service valves
( fusion welding quality ) ( third
6392 : 1971 Steel pipe flanges
revision )
. 6603 : 1972 Stainless steel bars and flats
3444 : 1987 Corrosion resistant high alloy
9866 : 1981 Marking system for valves
steel and nickel based castings
for general applications ( second 13159 Steel pipe flanges and Banged
rekrion ) ( Part 1) : 1991 fittings: Part 1 Dimensions

ANNEX B
( Clauses9.1 and 9.2.1 )
DIMENSIONS OF FLANGES AND DRILLING

Nominal Pressure ZntegtufCrey Cnst MnlLnble Cast Iron Steel Plate Flanges Integral Steel Flanges
PN Iron Flanges Integral Flanges for Welding

0.25 In accordance with Nil In accordance with Manufacturers

IS 6418 : 1971 IS 6392 : 1971 Standard
Table 2 Table 3
4

06 Table 3 In accordance with Table 5 do

IS : 6418-1971
Table 4

1.0 Table 6 ( Except Table 8 Table 11 do

for DN 80 in which
case the number of
holes shall be four )

1.6 Table 7 Table 8 Table 17 In accordance with

IS 6392 : 1971
Table 15

2.5 Table 10 Table 11 Table 23 Table 21

4-O - - Table 28 Table 26

 .

Bureau of Indian Standards

BIS is a statutory institution established under the Bureau of Indian Standards Act, 1986 to promote
harmonious development of the activities of standardization, marking and quality certification of goods and
attending to connected matters in the country.

Copyright
r
BIS has the copyright of&l1 its publications. No part of these publications may be reproduced in any form
without the prior permis&ion 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 (Publication), BIS.

Review 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 with 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 Additions.
This Indian Standard has been developed from Dot: No. HMD 17 ( 3744 )

Amendments Issued Since Publication

Amend No. Date of Issue Text Affected

BUREAU OF INDIAN STANDARDS

Headquarters:
Manak Bhavafi, 9 Bahadur Shah Zafar Marg, New Delhi 110002 Telegrams: Manaksanstha
Telephones: 323 0131,323 83 75,323 94 02 (Common to all offices)

Regional Offices: Telephone

Central : Manak Bhavan, 9 Bahadur Shah Zafar Marg 323 76 17,323 38 41

NEW DELHI 110002
Eastern : l/14 C.I.T. Scheme VII M, V.I.P. Road, Maniktola 337 84 99,337 85 61
CALCUTI-A 700054 337 86 26,337 9120

Northern : SC0 335-336, Sector 34-A, CI-IANDIGARH 160022 603843 _

,; { 60 20 25

Southern : C.I.T. Campus, IV Cross Road, MADRAS 600113 235 02 16,235 04 42

{ 235 15 19,235 23 15

Western : Manakalaya,E9 MID5 Marol, Andheri (East) 832 92 95,832 78 58

MUMBAI 400093 i ( 832 78 91,832 78 92

Branches : AHMADABAD. BANG&ORE. BHOPAL. BHUBANESHWAR.

COIMBATORE. FARIDABAD. GHAZIABAD. GUWAHATI.
HYDERABAD. JAIPUR. KANPUR. LUCKNOW. PATNA.
THIRUVANANTHAPURAM.
Reprography Unit, BIS, New Delhi, India
 AMENDMENT NO. 1 AUGUST 1996
TO
IS 13095 : 1991 BUTTERFLY VALVES FOR
GENERAL PURPOSES
(Page 2, clause 7.1, line 5 ) - Substitute the following for the existing:
PN 0.25, PN 0.6, PN 1.0, PN 1.6, PN 2.5 and PN 4.0.

(Hh4D17)
Reprography Unit, BIS, New Delhi, India