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SP-126-2007
Steel
In-Line
Spring-Assisted
Center
Guide
MSS SP-126-2007 Steel In-Line Spring-Assisted Center Guided Check Valves Standard Practice Developed and Approved by the Manufacturers Standardization Society of the Valve and Fittings Industry,Inc.127 Park Street,NE Vienna,Virginia 22180 Phone:(703)281-6613 Fax:(703)281-6671 e-mail:infomss-hq.org www.mss-hq.org Copyright MSS Provided by IHS under license with MSSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MSS STANDARD PRACTICE SP-126 iThis MSS Standard Practice was developed under the consensensus of the MSS Technical Committee 114 and the MSS Coordinating Committee.The content of this Standard Practice is the result of the efforts of competent and concerned volunteers to provide an effective,clear,and non-exclusive specification that will benefit the industry as a whole.This MSS Standard Practice is intended as a basis for common practice by the manufacturer,the user,and the general public.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 conformance is established only by reference in a code,specification,sales contract,or public law,as applicable.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 B.)In this Standard Practice all notes,annexes,tables,and figures are construed to be essential to the understanding of the message of the standard,and are considered part of the text unless noted as“supplemental”.All appendices appearing in this document are construed as“supplemental”.“Supplemental”information does not include mandatory requirements.The metric(SI)units and U.S.customary units in this Standard Practice are regarded separately as the standard;each should be used independently of the other.Combining or converting values between the two systems may result in nonconformance with this Standard Practice.This document has been substantively revised and rearranged from the previous edition.It is suggested that if the user is interested in knowing what changes have been made,that a direct page by page comparison should be made of this document.Any part of this Standard may be quoted.Credit lines should read“Extracted from MSS SP-126,2007,with permission of the publisher,the Manufacturers Standardization Society.”Reproduction prohibited under copyright convention unless written permission is granted by the Manufacturers Standardization Society of the Valve and Fittings Industry,Inc.Originally Approved December,1999 Copyright 2000 by Manufacturers Standardization Society of the Valve and Fittings Industry,Inc.Printed in U.S.A.Copyright MSS Provided by IHS under license with MSSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-标准分享网 w w w.b z f x w.c o m 免费下载MSS STANDARD PRACTICE SP-126 ii FOREWORD Work on this standard began about 1990 to fulfill the industrys need for a standard covering this unique class of check valves.The intent of the standard is to include in-line(no bonnet)check valves whose closure member is assisted by a spring in shutting before the flowing media can develop significant reverse velocity.Because this effect reduces the possibility of water hammer,these types of valves have also been termed“silent check valves”.This Standard Practice calls the valves“center guided”meaning that the closure member is guided into the center of the flow forcing the flowing media to pass around it.Additionally,the closure member remains perpendicular to the flowing media throughout its entire travel.This Standard Practice was first published in 2000.Copyright MSS Provided by IHS under license with MSSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MSS STANDARD PRACTICE SP-126 iiiTABLE OF CONTENTS SECTION PAGE 1 SCOPE.1 2 STANDARD UNITS.1 3 VALVE STYLES AND CLASSES.1 4 END CONNECTIONS.2 5 MATERIALS.2 6 DESIGN REQUIREMENTS.3 7 DIMENSIONS AND TOLERANCES.3 8 WELD REPAIR.7 9 TESTING.7 10 MARKING.8 11 PAINTING.8 TABLE 1 Face-to-Face Dimensions for Flanged Class 150,300,and 600 Globe Style Check Valves(Inch).4 1M Face-to-Face Dimensions for Flanged Class 150,300,and 600 Globe Style Check Valves(mm).4 2 Face-to-Face Dimensions for Flanged Class 900,1500,and 2500 Globe Style Check Valves(Inch).5 2M Face-to-Face Dimensions for Flanged Class 900,1500,and 2500 Globe Style Check Valves(mm).5 3 Face-to-Face Dimensions For Class 150,300,600,900,and 1500 Wafer Style Check Valves(Inch).6 3M Face-to-Face Dimensions For Class 150,300,600,900,and 1500 Wafer Style Check Valves(mm).6 4 Face-to-Face Dimensions for Class 150,300,and 600 Flange Insert Style Check Valves(Inch).6 4M Face-to-Face Dimensions for Class 150,300,and 600 Flange Insert Style Check Valves(mm).6 5 Minimum Shell Test Duration.7 6 Alternate Gas Seat Closure Test.7 7 Minimum Seat Test Duration.8 FIGURE A 1 Typical Globe Style Check Valves.9 A 2 Typical Wafer Style Check Valve.10 A 3 Typical Flange Insert Style Check Valve.10 A 4 Typical Threaded Style Check Valves.11 A 5 Typical Socket Weld Style Check Valve.12 ANNEX A Valve Types-Figures A1 through A5.9 B Referenced Standards and Applicable Dates.13 Copyright MSS Provided by IHS under license with MSSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-标准分享网 w w w.b z f x w.c o m 免费下载MSS STANDARD PRACTICE SP-126 11.SCOPE This Standard Practice covers in-line,center guided,internally spring-assisted type check valves made of steel,or other alloys listed in Table 1 of ASME B16.34.These valves,having the feature of limiting fluid flow to one direction only,are intended for use with clean fluids(i.e.fluids that contain no solids).2.STANDARD UNITS The value stated in either U.S.customary units or metric units are to be regarded separately as the standard.Within the text,the metric units are shown in parentheses.The values stated in each system are not exact equivalents;therefore,each system must be used independently of the other.Combining values from the two systems may result in nonconformance with this Standard Practice.Class and NPS are the standard descriptors for Pressure Class and Nominal Size for both metric and customary products covered under this Standard Practice.NPS,followed by dimensionless number,is the designation for nominal valve size.NPS is related to the nominal diameter,DN is used in international standards.The relationship is typically as follows:NPS DN 1/2 15 3/4 20 1 25 1-1/4 32 1-1/2 40 2 50 2-1/2 65 3 80 4 100 General Note:For NPS 4,the related DN is DN=25 x(NPS)3.VALVE STYLES AND CLASSES The valve styles covered by this Standard Practice are determined by the valve body configuration and include globe,wafer,insert,threaded,and socket weld valve styles.ASME Pressure Classes covered by this Standard Practice are 150,300,600,900,1500,and 2500.Valves meeting the requirements of this Standard Practice may be used within the pressure-temperature ratings of ASME B16.34,Standard Pressure Class.3.1 Globe Style Globe style check valves have two flanges integrally cast or forged in the valve body which is secured between the end gaskets and mating pipeline flanges by threaded fasteners that pass through bolt holes in these flanges.3.2 Wafer Style Wafer style check valves are secured between end gaskets and pipeline flanges by bolts which pass outside their pressure boundary wall.The body may be cylindrical or sculpted to allow for bolt clearance.3.3 Flange Insert Style Flange insert style check valves contain trim that protrudes into upstream and/or downstream piping.This valve style is secured between gaskets and pipeline flanges by bolts which pass outside the body circumference.This valve style is designed to function inside Schedule 40 or Standard Schedule pipe for Class 150 and 300 designs and Schedule 40 or 80 pipe for Class 600 designs.3.4 Threaded Style Threaded style check valves have American National Standard taper pipe threads(NPT)machined in each end of the valve body for assembly with similarly threaded piping or fittings.The end connections may be internally or externally threaded.3.5 Socket Weld Style The end of the pipeline is inserted into the valve body of the socket weld style check valve.The valve is then sealed into the line by welding around the circumference of the joint.Copyright MSS Provided by IHS under license with MSSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MSS STANDARD PRACTICE SP-126 24.END CONNECTIONS End connections for the valve styles covered by this Standard Practice are flanged,threaded,socket welded,or a combination of ends such as threaded by socket welded.4.1 Flanged Connections Unless otherwise authorized,all mounting surfaces of globe style check valves shall have dimensions in accordance with ASME B16.5.The face finish for globe,wafer,and flange insert style check valves shall conform to MSS SP-6.End connections for insert style check valves shall provide for the free movement of the trim and adequate clearance for pipeline flow.4.2 Threaded Connections Threads for threaded style check valves shall be NPT as specified in ASME B1.20.1.4.3 Socket Weld Connections End connections on socket weld style check valves shall be in accordance with ASME B16.11.Installation welding procedures are the responsibility of the user but shall prevent weld heat from warping or damaging the valve seat or any polymers or elastomers present in valve seats or bushings.5.MATERIALS The specification of materials of construction are the responsibility of the user.Typical nomenclature of individual valve parts are shown in Annex A,Figures A1 through A5.5.1 Valve Bodies Valve bodies shall be manufactured from materials listed in Table 1 of ASME B16.34.Chemical and mechanical properties for the body shall satisfy the requirements of the appropriate ASTM material specification.5.2 Valve Trim Valve trim may be manufactured from any of the materials listed in Table 1 of ASME B16.34 or other suitable materials.Polymer and Elastomer materials may be incorporated into the valve seat or disc to effect a tighter seal or in the valve bushing to provide smoother trim travel.Valve springs shall be manufactured of materials properly manufactured and formulated for springs.The material for all wetted parts shall have corrosion resistance at least equal to the body except by agreement between the manufacturer and the purchaser.Copyright MSS Provided by IHS under license with MSSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-标准分享网 w w w.b z f x w.c o m 免费下载MSS STANDARD PRACTICE SP-126 3 7.DIMENSIONS AND TOLERANCES 7.1 Face-to-Face Dimensions 7.1.1 Globe Style Face-to-Face dimensions for flanged globe style check valves Classes 150,300,600,900,1500,and 2500 are shown in Tables 1 and 2.Metric face-to-face dimensions for flanged globe style check valves Classes 150,300,600,900,1500,and 2500 are shown in Tables 1M and 2M.7.1.2 Wafer Style Face-to-Face dimensions for flanged wafer style check valves Classes 150,300,600,900,and 1500 are shown in Table 3.Metric face-to-face dimensions for flanged wafer style check valves Classes 150,300,600,900,and 1500 are shown in Table 3M.7.1.3 Insert Style Face-to-Face dimensions for flange insert style check valves Classes 150,300,and 600 are shown in Table 4.Metric face-to-face dimensions for flange insert style check valves Classes 150,300,and 600 are shown in Table 4M.7.2 Tolerances Tolerances for face-to-face dimensions for NPS 10 and smaller shall be plus or minus l/l6 inch(1.6 mm)and plus or minus l/8 inch(3.2 mm)for NPS 12 and larger.6.DESIGN REQUIREMENTS 6.1 Valve Envelope Except for insert style valves,each valve shall be designed so that in the closed position no internal component,stem or bushing,shall protrude beyond the face of the valve or end flanges.6.2 Valve Seats Valve seats shall be integral with the body or of the metallic seat ring design and may incorporate a hard facing overlay.The valve seat may be all metal or it may incorporate a polymer or elastomer.The valve seat shall comply with the valve trim requirements of Section 5.2.6.3 Valve Springs Valve springs shall be designed so the spring member is not over stressed when the valve is in the full open position.6.4 Wall Thickness The design requirements of this section only apply to the valve body.The disc is specifically excluded.Valve bodies shall have a minimum wall thickness as specified by ASME B16.34.6.5 Bolting Requirements Bolting shall conform to ASME Bl6.34 requirements.6.6 Body Joints Valves with bodies of sectional construction such that bolted or threaded body joints are subject to piping and mechanical loadings shall meet the criteria specified in ASME B16.34 for bolted and threaded body joints.Copyright MSS Provided by IHS under license with MSSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MSS STANDARD PRACTICE SP-126 4TABLE 1M Face-to-Face Dimensions for Flanged Class 150,300,and 600 Globe Style Check Valves Dimensions in mm SIZE CLASS 150 CLASS 300 CLASS 600 NPS SHORT BODY LONG BODY SHORT BODY LONG BODY SHORT BODY LONG BODY 1 114 127 121 216 140 216 1-1/2 146 165 152 241 168 216 2 159 203 165 267 184 292 2-1/2 178 216 184 292 203 330 3 191 241 200 318 219 356 4 216 292 232 356 257 432 5 241 330 264 400-508 6 254 356 279 445 314 559 8 305 495 330 533 371 660 10 356 622 391 622 435 787 12 457 699 495 711 540 838 14 533 787 584 838 572 889 16 572 864 610 864 660 991 18 610 978 660 978-1092 20 610 9786101016-119424 711 1295 711 1346-1397 TABLE 1 Face-to-Face Dimensions for Flanged Class 150,300,and 600 Globe Style Check Valves Dimensions in inches SIZE CLASS 150 CLASS 300 CLASS 600 NPS SHORT BODY LONG BODY SHORT BODY LONG BODY SHORT BODY LONG BODY 1 4-1/2 5 4-3/4 8-1/2 5-1/2 8-1/2 1-1/2 5-3/4 6-1/2 6 9-1/2 6-5/8 8-1/2 2 6-1/4 8 6-1/2 10-1/2 7-1/4 11-1/2 2-1/2 7 8-1/2 7-1/4 11-1/2 8 13 3 7-1/2 9-1/2 7-7/8 12-1/2 8-5/8 14 4 8-1/2 11-1/2 9-1/8 14 10-1/8 17 5 9-1/2 13 10-3/8 15-3/4-20 6 10 14 11 17-1/2 12-3/8 22 8 12 19-1/2 13 21 14-5/8 26 10 14 24-1/2 15-3/8 24-1/2 17-1/8 31 12 18 27-1/2 19-1/2 28 21-1/4 33 14 21 31 23 33 22-1/2 35 16 22-1/2 34 24 34 26 39 18 24 38-1/2 26 38-1/2-43 20 24 38-1/2 24 40-47 24 28 51 28 53-55 Copyright MSS Provided by IHS under license with MSSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-标准分享网 w w w.b z f x w.c o m 免费下载MSS STANDARD PRACTICE SP-126 5 TABLE 2M Face-to-Face Dimensions for Flanged Class 900,1500,and 2500 Globe Style Check Valves Dimensions in mm SIZE CLASS 900 CLASS 1500 CLASS 2500 NPS SHORT BODY LONG BODY SHORT BODY LONG BODY SHORT BODY LONG BODY 1-1/2 187 305 187 305-384 2 210 368 210 368 235 451 2-1/2 229 419 229 419-508 3 232 381 251 470 356 578 4 270 457 289 546-673 6 330 610 384 705-914