1、 STD-MSS SP-7L-ENGL L777 M 5770b40 0500774 L75 MSS SP-71-1997 Gray Iron Swing Check Valves,Flanged and Threaded Ends Standard Practice Developed and Approved by the Manufacturers Standardization Society of the Valve and Fittings Industry,Inc.127 Park Street,N.E.Vienna,Virginia 22180(703)281-661 3 CO
2、PYRIGHT Manufacturers Standardization Society of the Valve and FittingsLicensed by Information Handling Services COPYRIGHT Manufacturers Standardization Society of the Valve and FittingsLicensed by Information Handling ServicesMSS STANDARD PRACTICE SP-7 1 An MSS Standard Practice is intended as a ba
3、sis for common practice by the manufacturer,the user,and the general public.The existence of an MSS Standard Practice does not in itself precluded the manufacture,sale,or use of products not conforming to the Standard Practice.Mandatory conformance is established only by reference in a code,specific
4、ation,sales contract,or public law,as applicable.I Substantive changes in this 1997 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 material flagged with that in the previous edition.U.S.customary uni
5、ts in this SP are the standard;the metric units are for reference only.I Unless otherwise specifically noted in this MSS SP,any standard referred to herein is identified by the date of issue that was applicable to the referenced standard(s)at the date of issue of this MSS SP.(See Annex A.)In this St
6、andard Practice all notes,annexes,and figures are construed to be essential to theunderstanding of the message of the standard,and are considered part of the text unless noted as supplemental.All footnotes appearing in this document are con-strued as supplemental where their information does not mod
7、ify the text to which they refer.I Non-toleranced dimensions in this Standard Practice are nominal,and,unless specified,shall be considered for reference only.I Originally Approved February,1970 Any part of this standard may be quoted.Credit lines should read Extracted from MSS SP-71,1997,with permi
8、ssion of the publisher,the Manufacturers Standardization Society.Reproduction prohibited under copy-right convention unless written permission is granted by the Manufacturers Standardization Society of the Valve and Fittings Industry,Inc.Copyright,1984 by Manufacturers Standardization Society of the
9、 Valve and Fittings Industry,Inc.Printed in U.S.A.i COPYRIGHT Manufacturers Standardization Society of the Valve and FittingsLicensed by Information Handling Services COPYRIGHT Manufacturers Standardization Society of the Valve and FittingsLicensed by Information Handling Services.STD-MSS SP-71-ENGL
10、 1777 5770b40 050077b TbB MSS STANDARD PRACTICE SP-71 FOREWORD The 1997 edition of MSS SP.71.in addition to various editorial changes.includes changes to:provide a more complete metric version for reference use.delete the Class 800 Fressure-Temperature rating.and expand Annex C to include IS0 refere
11、nces.CONTENTS Section Page CONTENTS.ii 1.2.3.4.5.6.7.8.9.SCOPE.1 VALVE DESIGNATION.CLASSES AND SIZES.1 MATERIALS.1 DESIGN.2 WORKMANSHIP.3 TESTS.3 MARKING.4 PAINTING.4 PRESSURE-TEMPERATURE RATINGS.1 TABLE I.PRESSURE-TEMPERATURE RATINGS.NON-SHOCK.psi.2 2-HYDROSTATIC OR GAS SHELL TEST PRESSURE.4 3-DURA
12、TION OF TESTS.4 B1-PRESSURE-TEMPERATURE RATINGS.NON-SHOCK.bar.6 FIGURE AI.FULL WATERWAY METAL TO METAL SEAT.TYPE 1.5 A2.FULL WATERWAY COMPOSITION TO METAL SEAT.TYPE II.5 A3.CLEAR WATERWAY METAL TO METAL SEAT.TYPE III.5 A4.CLEAR WATERWAY COMPOSITION TO METAL SEAT.TYPE IV.5 ANNEX A.VALVE TYPES.FIGURES
13、 1 THROUGH 4.,.,.5 B-METRICUNITS.6 C.REFERENCED STANDARDS.7 COPYRIGHT Manufacturers Standardization Society of the Valve and FittingsLicensed by Information Handling Services COPYRIGHT Manufacturers Standardization Society of the Valve and FittingsLicensed by Information Handling ServicesMSS STANDAR
14、D PRACTICE SP-71 I.SCOPE 2.3 Classes I 1.1 This standard practice covers gray iron swing I I25 check valves with flanged and threaded ends for 250 general purpose senice in essentially horizontal lines.The use of swing check valves in steeply inclined or 2.4 Nominal Pipe Sizes.Nominal pipe sires cov
15、ered vertical lines requires special consideration.herein are:1.2 These valves are suitable within the sizes and a)N PS 2-24(DN 50.600)flanged end.pressure-temperature ratings specified herein for general purpose service.b)NPS 2-6(DN50-150)threaded end.1.3 This standard practice also includes.direct
16、ly or by reference,stipulations on chemical and physical 3.PRESSURE-TEMPEKATURE RATINGS properties of materials.and dimensions of end con-nections in common use.3.1 Pressure-Temperature ratings for the various classes of vah.es are shown in Table I.Metric units(bar)are shown in Table BI in Annex B.T
17、he ratings I I 2.VALVE DESIGNATION.CLASSES AND I.specified are for valves with metal seating surfxes.I SIZES Pressure-temperature ratings for valves with non-metallic seat materials must be limited to reflect the 2.1 Valve Types.(a)Valve types covered herein are illustrated in Figures AI through A4
18、in Annex A.Swing check valves of the full waterway type when fully opened shall have a flow of not less than the area of a circle having a diameter equal to the nominal pipe size.The clearway type shall allow the disc assembly to swing above the waterway when fully opened.Type I(Figure AI)-Full wate
19、rway,metal to metal seats.physical characteristics of these materials at each temperature,and may be lower but in no cahe higher than values shown in Tables I and B I.3.2 The temperature shown for the corresponding rating shall be the metal temperature of the pressure retaining parts.It shall be ass
20、umed that the metal temperature will be the temperature of the contained fluid.Use of a pressure rating at a metal temperature other than that of the contained fluid shall be the Type II(Figure A2)-Full waterway,composition responsibility of the user to metal seats.Type 111(Figure A3)-Clear waterway
21、,metal to 4.MATERIALS metal seats.4.1 General.This standard practice is intended to,Type IV(Figure A4)-Clear waterway,composition cover minimum physical and chemical requirements.to metal seats.Materials of superior properties may be substituted.Users are cautioned against applications with fluids 2
22、.2 Trims which may react chemically with any materials used in these valves.Consultation with the manufacturer is a)Bronze advised to determine suitability in cases of doubt.b)All-iron c)Stainless Steel 4.1.1 Body and Cover.The body and cover shall be d)Composition or Resilient in accordance with AS
23、TM A 126 Class B,“Gray Iron Castings for Valves,Flanges and Pipe Fittings.”I I I(a)Note:The valve sketches herein are for the purpose of illustration and nomenclature only.They are not in-tended to exclude any design meeting this Standard Practice.COPYRIGHT Manufacturers Standardization Society of t
24、he Valve and FittingsLicensed by Information Handling Services COPYRIGHT Manufacturers Standardization Society of the Valve and FittingsLicensed by Information Handling ServicesMSS STANDARD PRACTICE SP-71 I TABLE I.PRESSURE-TEMPERATURE RATINGS,NOK-SHOCK-psi I Class 125 Temp.14-24 2-12 Degrees F.N PS
25、 N PS-20 to 150 I30 I80 225 135 I90 200 I50 200 300 I65 110 325 350 I50 100 I 375 I30 425 I40 400 145 I 450 I25 250 K PS 14-24 2-12.x PS 500 300 460 280 440 270 415 260 395 250 375 240 355 230 335 220 315 210 290 200 270 250 General Note:See Table B1 for Metric Units.4.1.2 Seating Material.Metal-to-
26、metal seating sur-5.DESIGN faces shall be brass or bronze for bronze mounted I valves;gray iron or other ferrous material for all-iron I 5.1 General.When under the test pressure specified valves.Composition or resilient facing material shall in Section 7,valves shall be designed to prevent be rubber
27、(synthetic or natural),leather or suitable permanent distortion of the body,cover or seats.polymer.Other seating materials,either metal or composition,suitable for the intended senice may be 5.I.1 The closure assembly shall be designed to furnished when agreed between purchaser and assume the closed
28、 position by gravity under manufacturer.no flow conditions in a horizontal pipeline.Special arrangements of levers and springs 4.1.3 Hinge Pins.Hinge pins shall be wrought or weights may be necessary to assure brass,or stainless steel for bronze mounted valves;proper closure in lines which are incli
29、ned or wrought steel or stainless steel for all-iron valves.vertical.I I 4.1.4 Hinge.Non-ferrous hinges shall not be used 5.2 End Flanges on all-iron valves.4.1.5 Side Plugs.Side plugs,if used,shall be made I of gray iron,malleable iron,ductile iron or steel.I However,if used to support the hinge pi
30、n in bronze mounted valves,they shall be of brass,bronze,or brass or bronze bushed.4.I.6 Bolting.Bolts and studs connecting pressure containing parts shall develop physical strength not less than requirements of ASTM A 307.a)End flanges shall be integral with the valve body.Dimensions,tolerances and
31、 drilling shall be in accordance with ASME/ANSI B16.1.for each respective pressure class.The flanges shall be fully machined on the joint side in accordance with MSS SP-6,“Finishes for Con-tact Faces of Connecting End Flanges of Fer-rous Valves and Fittings.”2 COPYRIGHT Manufacturers Standardization
32、 Society of the Valve and FittingsLicensed by Information Handling Services COPYRIGHT Manufacturers Standardization Society of the Valve and FittingsLicensed by Information Handling ServicesMSS STANDARD PRACTICE SP-7 1 b)Face-to-face dimensions of flanged end valves shall be as follows:I Class 125(P
33、N 20).Full Waterway,I Figures A I and A2 ANSI B16.10,Class 125(PN 20)NPS 14-24(DN 350400)(a)NPS 242(DN 50-300);Class 125(PN 20),Clear Waterway,Figures A3 and A4 NPS 2-24(DN 50-600)(a)Class 250(PN SO),Full Waterway,Figure A 1 ANSI B16.10 Class 250(PN 50)NPS 1448(DN 350450)(a)(a)Manufacturers Catalog
34、Dimensions NPS 242(DN 50-300);5.3 Threaded Ends.Threaded end bodies may have hexagon,octagon,or round ends with ribs.Valve ends shall be threaded with taper pipe threads in accordance with ANSIIASME B1.20.1,“Pipe Threads.General Purpose(inch).”5.4 5.5 Body-Cover Bolting a)Dimensions of bolts and cap
35、 screws shall be in accordance with ANSI B18.2.1;nut dimensions in accordance with ANSIIASME B18.2.2.b)Nuts shall be threaded in accordance with ANSI BI.I,Coarse Threaded Series,Class 2B.c)Bolts,studs or cap screws shall be threaded in accordance with ANSI BI.1,Coarse Thread Series,Class 2A.Seating
36、Surfaces a)Disc seating surfaces may be integral or may be separate rings securely fastened to the disc.b)Body seats shall be separate rings.either shoulder or bottom seated,except that all-iron val1.e seats may be integral with the body casting at the manufacturers option.Driving lugs may protrude
37、into and reduce port area.5.6 Bypass and Drain Connections.Unless other-wise specified,bypass and drain connections shall be in accordance with MSS SP-45.“Bypass and Drain Connection Standard.”6.WORKMANSHIP 6.1 Valve Parts.Valve parts shall be designed and manufacturing tolerances set so as to provi
38、de inter-changeability in the product of any one manufacturer between units of the same size,class,type and design.6.2 Castings.All castings shall be clean and sound,without defects which will impair their service.No plugging,impregnation,welding or repairing of such defects will be allowed.7.TESTS
39、7.1 General.Pressure tests shall be made on all completed valves prior to shipment by the manufacturer.7.2 Shell Test.Valves.shajl be subjected to hydro-static or gas test pressure specified in Table 2.No visible leakage is permitted through the pressure I boundary wall or body-cover joint.Tests sha
40、ll be I held for periods specified in Table 3.Caution:Safety precautions must be taken when gas is used.7.3 Hydrostatic Seat Test.Valves shall be subjected to a hydrostatic seat test at not less than the maximum service pressure for which the valve is rated.The pressure shall be applied on the downs
41、tream side of the valve and the opposite side checked for leakage.The maximum permissible leakage rate shall be 40 millilitres per hour,per inch of nominal valve size.Test pressures shall be held for periods specified in Table 3.3 COPYRIGHT Manufacturers Standardization Society of the Valve and Fitt
42、ingsLicensed by Information Handling Services COPYRIGHT Manufacturers Standardization Society of the Valve and FittingsLicensed by Information Handling ServicesMSS STANDARD PRACTICE SP-71 7.4 Gas Seat Test.At the manufacturers option a gas seat test of not less than 80 psig(5.5 bar)may be used in li
43、eu of Hydrostatic Seat Test(7.3).This gas pressure to be applied as specified for hydrostatic seat test.The maximum permissible leakage rate shall be 4/10 of a standard cubic foot(12 litres)of gas per hour,per inch of diameter of nominal valve size.Test pressures shall be held for periods specified
44、in Table 3.Caution:Safety precautions must be taken when gas is used.MARKING Marking shall conform to MSS SP-25,Standard Marking System for Valves,Fittings,Flanges and Unions.PAINTING The painting of finished valves shall be optional with the manufacturer unless otherwise specified.I TABLE 2.MINIMUM
45、 HYDROSTATIC OR GAS SHELL TEST PRESSURE I Max.Service Rating l5OF(65C)150 bar psi bar psi Test Pressure 18.3 265 10.3 200 13.8 350 24.I 300 60.3 875 34.5 5M 36.2 525 20.7 I TABLE 3.MINIMUM DURATION OF TESTS 1 r.Shell Test,Seconds Seconds DN NPS Seat Test 2-8 50-200 30 60 250450 10-18 30 120 180 500-
46、Larger 20-Larger 6l COPYRIGHT Manufacturers Standardization Society of the Valve and FittingsLicensed by Information Handling Services COPYRIGHT Manufacturers Standardization Society of the Valve and FittingsLicensed by Information Handling ServicesMSS STANDARD PRACTICE SP-71 I ANNEX A-VALVE TYPES-F
47、IGURES Al THROUGH A4 I e BODY COMPOSITION DkC.DISC HOLDER FULL WATERWAY METAL TO METAL SEAT TYPE I FIGURE AI FULL WATERWAY COMPOSITION TO METAL SEAT TYPE II FIGURE A2 COVER L I CLEAR WATERWAY METAL TO METAL SEAT TYPE III FIGURE A3 COVER nn n r/r lSC HOLDER CLEAR WATERWAY COMPOSITION TO METAL SEAT TY
48、PE IV FIGURE A4 5 COPYRIGHT Manufacturers Standardization Society of the Valve and FittingsLicensed by Information Handling Services COPYRIGHT Manufacturers Standardization Society of the Valve and FittingsLicensed by Information Handling ServicesMSS STANDARD PRACTICE SP-7 1 ANNEX B-METRIC UNITS I T
49、ABLE BI.PRESSURE-TEMPERATURE RATINGS,NON-SHOCK-bar I PN 20 PN 50 Temperature Degrees C.DN DN DN DN 50-300 350400 50-300 350-600-29 to 65 200 15.3 23.I 7.0 10.4 I75 16.5 25.7 7.7 11.2 I50 17.7 28.3 8.5 11.9 125 19.0 30.9 9.2 12.8 100 20.7 34.5 10.3 13.8 17.2 8.6 232 17.9 8.8 225 13.8 205 14.0 20.5 9.
50、6 I,I Note:For definitions of DN and PN.see International Standards IS0 6708 and IS0 7268,respectively,or MSS SP-86.I 6 COPYRIGHT Manufacturers Standardization Society of the Valve and FittingsLicensed by Information Handling Services COPYRIGHT Manufacturers Standardization Society of the Valve and
