? br>Cast Iron Gate Valves
Flanged and Threaded Ends
Standard Practice
Developed and Approvedby the
Manufacturers Standardization Societyof the
Valve and Fittings Industry, Inc.
127 Park Street,NE
Vienna, Virginia 22180
(703) 281-661 3
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STD*MSS SP-70-ENGL L778 ? bllO
MSS SP-70 STANDARD PRACTICE
An MSS Standard Practice is intended as ? practice by the
manufacturer, the user,and the generalpublic. The existence of an MSS
Standard Practice does not in itself preclude the manufacture, sale, or use of
products not conforming to the Standard Practice. Mandatory conformanceis
established only by reference in ? tion, sales contract,or public
law, as applicable.
Unless otherwise specifically noted in thisMSS SP, any standard referred to herein is identified by the date of
issue that was applicable to the referenced standard(s) atthe date of issue of this MSS SP. See Annex C.
In this Standard Practice ? and figures are construedto be essential to the understanding ofthe
message of the standard, and are considered part of the text unless noted as ‘supplemental.’ All footnotes
appearing in this document are construed as ‘supplemental‘ where their information doesnot modify the text to
which they refer.
U.S. customary units in this SP are the standard; the metric unitsare for reference only.
Substantive changes in this1998 edition are “flagged’’ by
parallel bars as shown on the margins of this paragraph.
The specific detail of the change may be determined by
comparing the materialflaged with that in the previous
Iedition. I
Any part of this standmd may be quoted. Credit lines should read ‘Extractedporn MSS SP-70, 1998, with
penniwwn of the publisher, the Manufacturers Standardization Society.’ Reproduction prohibited under
copyright convention unless writtenpermìwwn is granted by the Manufacturers Standardization Societyof the
Vahe and Fittings Inhtry, Inc.
OrigbUy Approved 1970
Copyright 8,1984 by
Manufacturers StandardizationSociety
of the
Valve and Fittings Industry, Inc.
printed in U.S.A.
i
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MSS SP-70 STANDARD PRACTICE
FOREWORD
The 1998 edition of MSS SP-70, in addition to various editorial changes, includes changes to: providea
more complete metric versionfor reference use, delete the Class 800 Pressure-Temperature rating, and
expand Annex Cto include IS0 references.
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MSS STANDARD PRACTICE SP-70
CONTENTS
SECTION PAGE
FOREWORD ......... ii
...
CONTENTS ........... m
1. SCOPE ............... 1
2. VALVEDESIGNATION. CLASSES AND SIZES ...... 1
3. PRESSURE-TEMPERATURE RATINGS ...... 1
4. MATERIALS ......... 1
5. DESIGN .............. 2
6. WORKMANSHIP ............ 4
7. TESTS ............... 4
8. MARKING ........... 4
9. PAINTING ........... 4
TABLE1 .PRESSURE-TEMPERATURE RATINGS.NON-SHOCK-psi ... 2
TABLE ? GAS SHELL TEST PRESSURE .......... 4
TABLE ? STS ......, ........... 4
TABLE B1 .PRESSURE-TEMPERATURE RATINGS, NON-SHOCK-bar ... 8
FIGURE ? OLDWEDGE GATE VALVE. TYPE ? -RISING STEM. SOLDWEDGE GATE VALVE. TYPE ? SPLIT-WEDGE GATE VALVE. TYPE II ... 6
4 -NON-RISING STEM. SPLITWEDGE GATE VALVE. TYPE II ..... 6
5 ? UBLE-DISC. PARALLEL SEAT GATE VALVE. TYPE III ..... 7
6 ? D0UBLE.DISC. PARALLEL SEAT GATE VALVE.
TYPE III ........... 7
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MSS SP-70 STANDARD PRACTICE
1. -SCOPE 3. PRESSURE-TEMPERATURERATINGS
I. ? racticecovers cast iron gate 3.1 Pressure-temperatureratings for thevarious
valves with flanged or threaded ends. classes of valves are shown in Table 1. Metric units
(bar) are shown in TableBI in Annex B. The ratings
1.2 These valves are suitable within the sizes and specified are for valves with metal-to-metal seating
pressure-temperature ratings specified herein for surfaces. Pressure-temperature ratings for valves
general purpose service. with non-metallic seat materials must be limited to
reflect the physical characteristicsof these materials
1.3 This standard practice also includes, directly at each temperature, and may be lower but in no
or byreference, stipulations on chemical and case higherthan the values shown in Tables1 and ? properties of materials, and dimensions of
end connections in common use. 3.2 The temperature shown for the corresponding
rating shah be the metal temperatureof the pressure
retaining parts. It shall be assumed that the metal
2.VALVE DESIGNATION, CLASSES AND temperaturewill be the temperature of the contained
SIZES fluid. Use ofa pressure ratingat ? e
other than that of the contained fluid shall be the
2.1Valve Types. Valve types covered herein are responsibility of the user.
illustrated in FiguresA 1, A2, A3, A4, A5,and A6 in
Annex A.
4. MATERIALS
Type I-Solid Wedge Disc
Type II-Split Wedge Disc
4.1 General. This standard practice is intended to
Type Ill-Double Disc, Parallel Seat cover minimum physical and chemical requirements.
Note: The valve sketches hereinare for the purpose Materials of superior mechanical properties may be
of illustration and nomenclature only. They are substituted. Users are cautioned against applications
not intended to exclude any design meeting this withfluids which may react chemically with any
Standard Practice. materials used in thesevalves. Consultation with the
manufacturer is advised to determine suitability in
2.2 Construction cases of doubt.
Designation- NT-Non-Rising Stem, Threaded End
NF-Non-Rising Stem, Flanged End 4.1.1 Body and Bonnet. Body and Bonnet shall be
OT-Outside Screw and Yoke, gray iron in accordance with ASTM A126 Class B
Threaded End or ductile iron in accordance with ASTM ? tside395. Screw and Yoke, ? ed End I
4.1.2 Seating Material. Metal-to-metal seating sur-
2.3 T- faces shall be brass or bronze for bronze mounted
(a) All Bronze valves; cast iron or other ferrous materialfor all-iron
(b) All Iron valves. Othermaterials suitable for the intended
(c) Bronze with Ferrous Stem service may be furnished when agreed between pur-
I (d)Non-Metallic Seating ? facturer.
2.4Classes 4.1.3 Stems. Stem material shall be brass or bronze,
125 either cast or wrought for bronze mounted valves,
250 wrought steelfor all-iron valves.
2.5 sizes. 4.1.4 Handwheels. Handwheels may be gray iron,
(a) NPS 2-48 @N5&1200), flanged end ductile iron, malleable iron or steel at the manufac-
I (b) NPS 2-6 @N50-150), threaded end ? ion.
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MSS SP-70 STANDARD PRACTICE
I TABLE ? RATURE RATINGS, NON-SHWK-psi I
CLASS 125 CLASS 250
Temp. NPS NPS NPS NPS NPS
Degrees F. 2-12 14-24 14-24 2-12 30-48
-20 to 150 200 150 150 500 300
200 190 135 115 460 280
, 225 180 130 100 440 270
250 175 125 85 415 260
275 170 120 65 395 250
300 165 110 50 375 240
325 155 105 355 230
350 150 100 335 220
375 315
145 ? 140 200
425 130 270
450 125 250
*.
See Table BI for Metric U&.
4.1.5 Bo@ Boltsand studs connecting pressure
contah^i"i"i^i"ig-p"-3s shall develop physical strength not -dge
less than requirements-of ASTM ? DN5G600)
ASME B16.10
4.1.6 Glands, Glands shall be madefrom brass, NPS 3W;*(DN750-1200)
bronze, gray iron or other ferrous material. Double Disc (Parallel Seat)
Sizes 2-12; ASME B16.10
NPS 1418.* (DN350-450)
5. DESIGN
Class 250 (PN501
5.1 *c& When under the test pressure speci- Solid or Split Wedge ? fied in Skctio~~7, valves shall be designed to prevent (Parellel Seat)
permanent distortion of the body, bonnet, or seats. ? quot;)
I desiped toprevent permanent
Valve stems shall be ASME B16.10.
distortion when the valve is operated at full rated
working pressure. 5.3 Threaded Ends.Threaded end bodies may
have hexagon, octagon or round ends with ribs.
Valveends shall be threadedwith tapered pipe
5'2 shall be integral with the valve threads in accordance with ASME ? esbody. Dimensions, toleran& and drilling shall
be in accordance with ASME B16.1 for each 5.4 Body-Bo~etBolting
respective pressure class. The flanges shall be (a) Dimensions of bolts and cap screws shall
fully ,mchined on the joint side in accordance be in accordance with ASME B18.2.1.Nut
with MSS SP-6, dimensions shall be in accordance withASME
BR22
(b) Faceto-face dimensionsof flanged end
valves shall be as follows: @) Nuts shall be threaded in accordance with
ASME B1.1, Coarse thread series, Class2B.COPYRIGHT Manufacturers Standardization Society of the Valve and Fittings
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STD-MSS SP-70-ENGL L778 5770bYO 0503073 TOB
MSS STANDARD PRACTICE SP-70
(c) Bolts, studs or cap screws shall be threaded (c) Stem seals not requiring ? accordance withASME B1.1, Coarse thread suitable for the service conditions, may be
series, Class 2A. furnished.
5.5 Yokes ? nd Yoke (OS ? olting. Studs, stud bolts, hinge bolts
Yokes on bonnets may be integral or of bolted-on or headed bolts through drilled or slotted holes in
Iconstruction. ? flange may be used. In all cases,
gland bolting shall be securely held in place and
5.6 Wedge and Disc Guides and Disc Spreading shall provide adequate adjustment for progressive
Device compression of packing material.
(a) Wedge discs shallbe guided to ensure that
the seating surfaces of the wedgewill not 5.10 Backseat. Valves shall be designed to have a
touch the body seat surfaces until near the backseat. Repacking under pressure is hazardous
point of closure. and is not recommended.
(b) Double discs shallbe provided with guides 5.11 Stems
or linkage or disc spreading devices between (a) The upper endof outside screw and yoke
the gates or ? these which will valve stems and the lower end of non-rising
hold the gates in proper relation with each valve stems shall be threaded with single or
other and the stem, and will prevent the seat- multiple Acmetype thread, or Uegree
ing surfaces from rubbingagainst the body or thread approximating the stub form, pre-
bonnet during operation. cision cut to fit the engaging member.
(c) Body guides shall be cast integral with the (b) Outside screwand yoke stems shall be of
body except that NPS 16 (DN400) and larger sufficient length so as to be at least flush
I may have separate guides of bronze or other ? the yoke nut after the disc
bearing material securely fastededto the body. wedging has been worn into its lowest posi-
All guide surfacesshall be smooth and true. tion. The design shall be such as to prevent
any possibility of the wedge or disc leaving
(d)Selection of materialfor disc spreading the stem, or the stem turning during the
devices shall be the manufacturer‘s option. operation of the valve.
5.7 Seating Surfaces (c) Non-rising stem gate valves having sep-
(a) Disc seating surfaces may be integral or arate stem engaging members shall be so
may beseparate rings securely fastenedto the designed as to prevent rotation or pulling
disc. out of the disc or wedge.
(b) Body seats shall be separate rings, either 5.12Handwheels. Handwheels shall be of the
shoulder or bottom seated, except that all- spoke type only. Webbed or disc type are not per-
iron valve seats may beintegral with the body missible.Handwheels shall be markedwith the
casting at the manufacturer’s option. Driving direction of movement for opening of the valve.
lugs mayprotrude into andreduce port area.
5.13 Bypass and Drain Connections. Unless other-
5.8 Glands wise specified, bypass and drain connections shall
(a) Glands may be threaded or bolted type. be in accordance withMSS SP-45.
(b) Bolted glands may be solid, solid-bushed,
or two-piecedself aligning design. Useof
open bolt slots in glands shall not be per-
mitted unless hinge bolts are used.COPYRIGHT Manufacturers Standardization Society of the Valve and Fittings
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S TAN DA RD PRACTICE SP-70 WS PRACTICE STANDARD
6 YORKMANSHIP maximum service pressure for which the valve is
rated. Test pressure shallbe applied successively on
6.1 General.Valve parts shall be designed and each side of the closed gate, and the opposite side
manufacturing tolerances set so as to provide inter- checked for leakage. As an alternate method for
changeability inthe product of any one manufacturer double disc valves, the pressure may be applied
between unitsof the samesize, class, type, and design, inside the bonnet or body withthe discs closedand
except the individual fitof the wedge or disc in the both sideschecked for leakage. The maximum
body. permissible leakage rate on each seat shall be 10
milliliters perhour per inchof diameter of nominal
6.2 Castin All castings shall be cleanand sound valve size (.O7 mm3/sec ? ures shall
without+ efects whichwill impair their servioe. No be held for periods specified in Table3.
plugging, impregnation, welding or repairingof such
defects will be allowed. TABU ? SECONDS,
MINIMUM I
7. TESTS ? la ? be
made on all completed valves prior to shipment by
the manufacturer.
250-450
120
7.2 Shell Test. Valves in the partially open posi-
tion with both ends closed.shall be subjected to
hydrostatic or gas test pressure specified in Table 7.4 Gas Seat Test. At the manufacturer's option,
2. No visibleleakage is permitted through the ? not less than 80 psi (5.5 bar) may be
pressure boundary walls or body-bonnet joint. used in lieu of Hydrostatic Seat Test(7.3). The gas
Leakage through the stem packing or stem seals gressure is to be applied as specified for hydrostatic
shall not be cause for rejection. The test pressure seattest. The maximum permissible leakage rate
shall be held for the durationspecified in Table 3. for each gate seat shall be 1/ 10 of ? br>foot of gas per hour, per inch ofdiameter of nominal
Caution: Safety precautions must be taken when valve size (2 mm3/sec ? ures shall
gsisused. be held for periods specified in Table 3.
Caution: Safety precautions be taken when
TABLE ? MINIMUM must
I SHELL gas is wed.Max. Servioe Rating
lSOF (6X) Test Pressure 8. MARKING
bru bar
Psi Psi Marking shall conform to MSS SP-25.
150 10.3 265 18.3
#)o 13.8 350 24.1
300 20.7 525 36.2 9. PAINTING
c 5Qo 34.5 875 60.3
The painting of finished valves shall be optional
with the manufacturer unless otherwisespecified.
7.3 Hydrostatic Seat Test: Valves shall be sub-
jected to ? test at not less than theCOPYRIGHT Manufacturers Standardization Society of the Valve and Fittings
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STD-MSS SP-70-ENGL L978 ? 880
MSS STANDARD PRACTICE SP-70
ANNEXA VALVE TYPES
PART NAMES PART NAMES
I-Handwheel nut ? ts and nuts I-Handwheel nut IO-Stufi"ing-box bolth and
2-Handwheel I3”Stem packing. or stem 2-Handwheel nuts or studs and nuts
3--Stem nut seals 3-Stem ?
5--Stem nut bolts and nuts 18-Bonnet &Gland flange 12-Bonnet
6--Yoke 19-Bonnet gasket 5-Gland 13-Bonnet bolts and nuts
7-Stem 20-Bonnet bolts and nuts &Gland bolts and nuts IbBody
8“Glapd flange 21 Wedge 7-Stern packing. or stem IS-Upper wedge or wedge
9-Gland 25 Seat ring seals bushing
IO-Yoke bolts and nuts 26-Body 8-Stuffing box I6”Seat ring
I ? gland eye- 9-Stuffing-box gasket 17-Wedge
bolts and nuts.
RISING STEM, SOLID-WEDGE GATE NON-RISING STEM, SOLID-WEDGE GATE
VALVE VALVE
FIGURE Al FIGURE A2
Note: The valvesketches herein are for the
purpose of illustration and nomenclature only.
They are not intended to exclude any design
meeting this Standard Practice.COPYRIGHT Manufacturers Standardization Society of the Valve and Fittings
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STD-HSS SP”ID-ENGL L778 5770bll0 050107b 717 m
MSS SP-70 STANDARD PRACTICE
ANNEX ? PART NAMES PART NAMES
I-Handwheel nut 12-Gland lug boltsnuts and I-Handwheel nut IO-Stuffing-box bolts and
2-Handwheel 13-Stem packing, or stem 2-Handwheel -nuts or studs and nuts
3-Stem nut ScalS 3-Stem ?
5-Stem nut bolts and nuts 18-Bonnet 4“Gland flange 12-Bonnn
&Yoke 19-Bonnet gasket 5-Gland 13-Bonnet bolb and nuts
7-Stem nuts %Bonnetand bolts -land bolts and nuts 14-Body
&Gland flange 21-Split dge 7-Stem packing, or stem 15-Upper wedge or wedge
9-Cland 25-Seat ring seals bushing
IO-Yoke boltsnuls and 26wy Il-Stuffing box If-Seat ring
1 I-Cland bolts or gland eye- 9-Stuffing-box gasket I7”Split wedge
-bolts and nuts
Type II Type II
RISING STEM, SPLIT-WEDGE GATE NON-RISING STEM, SPLIT-WEDGE GATE
VALVE VALVE
FIGURE A3 FIGURE A4
Note: The valve sknche-s herein are for the
purposc ofilustration and nomenclatureonly.
They are not intended to exclude any design
Mingthis Standard Practice.COPYRIGHT Manufacturers Standardization Society of the Valve and Fittings
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MSS STANDARD PRACTICE SP-70
ANNEX ? ART NAMES PART NAMES
I-Handwheel nut I3”Stem packaking. or stem I-Handwheel nut ?
2-Handwheel seals 2-Handwheel 12LBonnet
3-Stem nut I7”Stem back seat collar 3-Stem 13”Bonnet bolts and nuts
4-Stem nut retaining ring IB-Bonnet &Gland flange 14-Body
&Yoke 19-bonnet gasket 5-Gland 15-Upper wedge or wedge
7-Stem ”Bonnet bolts and nuts 6”Gland bolts and nuts bushing
B-Gland flange 2-Upper spreader 7-Stem packing or stem IGSeat Ring
9-Gland 23-Disc sea$ 18”Upper spreader
IO-Yoke bolts and nuts 24”Lower spreader 8”Stuffing box I9”Disc
I I-Gland bolts or gland eye- 25-Seat ring 9”Stuffing-box gasket 20”Lower spreader
bolts and nuts 2f“Y IO-Stuffing-box bolts and
nuts or studs and nuts
Type III Type III
RISING STEM, DOUBLE-DISC PARALLEL NON-RISING STEM,DOUBLE-DISC PARALLEL
SEAT GATEVALVE SEAT GATEVALVE
FIGURE A5 FIGURE A6
Note: The valve sketches herein are for the
purpose of illustrationand nomenclatureonly.
They are not intended to exclude any design
meeting this Standard Practice.COPYRIGHT Manufacturers Standardization Society of the Valve and Fittings
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MSS STANDARD PRACTICE SP-70
ANNEX ? >I TABLE B1 ? ATURE RATINGS, NON-SHOCK-bar I
PN20 PN50
Temperature
Degrees C. DN DN DNDN DN
50-300 350-600 750-1200 350-60050-300
-29 to 65 13.8 10.3 10.320.7 34.5
100 12.8 9.2 7.419.0 30.9
125 11.9 8.5 5.317.7 28.3
150 11.2 7.7 3.316.5 25.7
I75 10.4 7.0 15.3 23.1
200 9.6 20.5 14.0
205 13.8
225 8.8 17.9
232 8.6 17.2
NOTE: For definitions of DN and PN, see International Standard IS0 6708 and IS0 7268,
respectively, or MSS SP-86.COPYRIGHT Manufacturers Standardization Society of the Valve and Fittings
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SP-70-ENGL
STD*MSS 0503077 Y2b
MSS SP-70 STANDARD PRACTICE
I ANNEX ? STANDARDS
This annex is an integral part of this Standard Practice which is placed after the main text for convenience.
List of standards and specifications referencedin this Standard Practice show the yearof approval.
ASME, ANSIIASME, ANSI, ASMEIANSI
B1.1-1989 Unified Inch ScrewThreads (UN andUNR Thread Form)
B1.20.1-1983(R1992) PipeThreads, General Purpose (Inch)
B16.1-1989 CastIron Pipe Flanges and Flanged Fittings (Class 25, 125,250,and 800)
B16.10-1992 Famt*Faoe End-to-Endand Dimensions Valves of
B18.2.1-1996 Squareand Hex Bolts and Screws, Including Askew Head Bolts, Hex Cap Screws,and Lag
Screws
818.2.2-1987 (R 1993) Squareand HexNuts
-ASTM
A 12695 SpecifcationforGray Iron Castings for Valves,Flanges, andPipe Fittings
A 307-94Specification for CarbonSteel Bolts andStuds, 60,OOO psiTensile Strength
A395-88 (R 1993)Specification for Ferritic Ductile Iron Pressure ? gs for Use at Elevated
Temperatures
A 53684 (R 1993)Specification forDuctile IronCastings
MSS
SP-fk1990 Standard Finishes for Contact Facesof Pipe Flanges and Connecting-End Flangesof
Valves and Fittings
SP-2S1998 Standard Marking System forValves, Fittings, Flanges, and Unions
SP45-1992 Bypass and Drain Connection Standard
SP-861997 Guidelines for MetricData in Standards forValves, Flanges, Fittings and Actuators
-IS0
6708-1995 Pipe Components- Definition of Nominal Pipe Size
7268-1983 (Amend 1, 1984) Pipe Components- Definition of Nominal Pressure
Publications of the following organizations appear on the above list:
ASME The American Society of Mechanical Engineers
Three Park Avenue, New York, New York 100165990
ASTM American Society for Testing and Material
100 Bar Harbor Drive, West Conshohoken, Pennsylvania 19428-2959
MSS Manufacturers Standardization Societyof the Valve and Fitting Industry, Inc.
127 Park Street, N.E., Vienna, Virginia 22180
IS0 International Organization for Standardization
1, mede VarenBrd, Case postale 56, CH-1211 Geneve 20, Switzerland
Publications appearing above which have been approvedas American National Standardsmay be obtained from:
ANSI American National Standards Institute, Inc.
11 West 42nd Street, New York, New York 10036COPYRIGHT Manufacturers Standardization Society of the Valve and Fittings
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