1、 MSS SP-71-2011 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, NE Vienna, Virginia 22180-4602 Phone: (703) 281-6613 Fax: (703) 281-6671 E-mail: inf
2、omss-hq.org www.mss-hq.org MSS MSS STANDARD PRACTICE SP-71i This MSS Standard Practice was developed under the consensus of the MSS Technical Committee 106 and the MSS Coordinating Committee. The content of this Standard Practice is the resulting efforts of competent and experienced volunteers to pr
3、ovide an effective, clear, and non-exclusive standard that will benefit the industry as a whole. This MSS Standard Practice describes minimal requirements and is intended as a basis for common practice by the manufacturer, the user, and the general public. The existence of an MSS Standard Practice d
4、oes not in itself preclude the manufacture, sale, or use of products not conforming to the Standard Practice. Mandatory conformance to this Standard Practice is established only by reference in other documents such as a code, specification, sales contract, or public law, as applicable. MSS has no po
5、wer, nor does it undertake, to enforce or certify compliance with this document. Any certification or other statement of compliance with the requirements of this Standard Practice shall not be attributable to MSS and is solely the responsibility of the certifier or maker of the statement. “Unless in
6、dicated otherwise within this MSS Standard Practice, other standards documents referenced to herein are identified by the date of issue that was applicable to this Standard Practice at the date of approval of this MSS Standard Practice (see Annex C). This Standard Practice shall remain silent on the
7、 validity of those other standards of prior or subsequent dates of issue even though applicable provisions may not have changed.” By publication of this Standard Practice, no position is taken with respect to the validity of any potential claim(s) or of any patent rights in connection therewith. MSS
8、 shall not be held responsible for identifying any patent rights. Users are expressly advised that determination of patent rights and the risk of infringement of such rights are entirely their responsibility. In this Standard Practice, all text, notes, annexes, tables, figures, and references are co
9、nstrued to be essential to the understanding of the message of the standard, and are considered normative unless indicated as “supplemental”. All appendices, if included, that appear in this document are construed as “supplemental”. Note that supplemental information does not include mandatory requi
10、rements. U.S. customary units in this Standard Practice are the standard; (SI) metric units are for reference only. Substantive changes in this 2011 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
11、material flagged with that in the previous edition. Non-toleranced dimensions in this Standard Practice are nominal, and, unless otherwise specified, shall be considered “for reference only”. Excerpts of this Standard Practice may be quoted with permission. Credit lines should read Extracted from MS
12、S SP-71-2011 with permission of the publisher, Manufacturers Standardization Society of the Valve and Fittings Industry. Reproduction and/or electronic transmission or dissemination is prohibited under copyright convention unless written permission is granted by the Manufacturers Standardization Soc
13、iety of the Valve and Fittings Industry Inc. All rights reserved. Originally Approved: February 1970 Originally Published: March 1970 Current Edition Approved: August 2010 Current Edition Published: October 2011 MSS is a registered trademark of the Manufacturers Standardization Society of the Valve
14、and Fittings Industry, Inc. Copyright , 2011 by Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. Printed in U.S.A. MSS STANDARD PRACTICE SP-71ii FOREWORD The 1997 edition of MSS SP-71, in addition to various editorial changes, includes changes to: 1) provide a more comp
15、lete metric version for reference use; 2) delete the Class 800 Pressure-Temperature rating; and 3) expand Annex C to include ISO references. The 2005 edition of MSS SP-71 added minimum wall requirements that were previously omitted. The addition of the minimum wall thickness requirements are necessa
16、ry to qualify the valves for Class 125 and Class 250 pressure-temperature designation/rating as defined in ASME B16.1 and Table 1 of this MSS Standard Practice. This edition also deleted the PN designations, which were easily confused with designations in international standards that are based on ot
17、her material specifications and pressure-temperature rating procedures. ISO references were deleted from Annex C. This 2011 edition of MSS SP-71, in addition to various editorial and formatting updates, clarifies the leakage rate in Section 7.4 and updates the organizations and references in Annex C
18、. 127 Park Street, NE Vienna, VA 22180-4602 703-281-6613 FAX 703-281-6671 www.mss-hq.org e-mail: infomss-hq.org EXECUTIVE DIRECTOR: Robert F. ONeill ERRATA SHEET FOR MSS SP-71-2011 (Gray Iron Swing Check Valves, Flanged and Threaded Ends) February 22, 2013 This “normative” errata correction applies
19、only to MSS SP-71-2011 edition (current), involving Gray Iron Swing Check Valves, Flanged and Threaded Ends. NOTE THE FOLLOWING CORRECTIONS: Section 4 Materials Page 2 (right-side column), Section 4.1.5 Bolting (only) and 4.1.6 Glands (only). Both of these sections (with their specific heading only)
20、 should be deleted. This correction matches previous editions. * Note that Section 4.1.5 Side Plugs and Section 4.1.6 Bolting remain unchanged and in force. This Errata Sheet has been inserted into the Standard Practice. For those who obtained the Standard Practice before the February 22, 2013 publi
21、cation date indicated above or otherwise do not already have this information, please include this Errata Sheet within your existing 2011 edition of the Standard Practice. Future edition of this Standard Practice will include this corrected information. PRESIDENT: G.M. Johnson United Valve VICE PRES
22、IDENTS: M.A. Clark NIBCO, Inc. F. Washburn Rotork Controls, Inc. TREASURER: J. Barker DeZURIK APCO, Inc. “The Technical Voice of the Industry” Manufacturers Standardization Society of the Valve And Fittings Industry, Inc. MSS STANDARD PRACTICE SP-71iv TABLE OF CONTENTS SECTION PAGE 1 SCOPE . 1 2 VAL
23、VE DESIGNATION, CLASSES, AND SIZES . 1 3 PRESSURE-TEMPERATURE RATINGS . 1 4 MATERIALS . 2 5 DESIGN . 3 6 WORKMANSHIP . 4 7 TESTS 4 8 MARKING 4 9 PAINTING . 4 TABLE 1 Pressure-Temperature Ratings, Non-Shock, psi 2 2 Shell Test Pressure, Minimum . 4 3 Test Duration, Minimum . 4 B1 Pressure-Temperature
24、 Ratings, Non-Shock, bar 6 FIGURE A1 Type I Full Waterway, Metal-to-Metal Seat 5 A2 Type II Full Waterway, Composition-to-Metal Seat . 5 A3 Type III Clear Waterway, Metal-to-Metal Seat . 5 A4 Type IV Clear Waterway, Composition-to-Metal Seat 5 ANNEX A Valve Types Figures A1 through A4 . 5 B SI (Metr
25、ic) Units 6 C Referenced Standards and Applicable Dates . 7 MSS STANDARD PRACTICE SP-711 1. SCOPE 1.1 This Standard Practice covers gray iron swing check valves with flanged and threaded ends for general purpose service. The use of swing check valves in steeply inclined or vertical lines requires sp
26、ecial consideration. 1.2 This Standard Practice also includes, directly or by reference, stipulations on chemical and mechanical properties of materials and dimensions of end connections in common use. 2. VALVE DESIGNATION, CLASSES, AND SIZES 2.1 Valve Types Valve types covered herein are illustrate
27、d in Figures A1 through A4 in Annex A (1). Swing check valves, of the full waterway type when fully opened, shall have a flow area 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
28、fully opened. Type I Full Waterway, Metal-to-Metal Seat (See Figure A1) Type II Full Waterway, Composition-to-Metal Seat (See Figure A2) Type III Clear Waterway, Metal-to-Metal Seat (See Figure A3) Type IV Clear Waterway, Composition-to-Metal Seat (See Figure A4) Note: (1) The figures in Annex A are
29、 for the purpose of illustration and nomenclature only. They are not intended to exclude any design meeting this Standard Practice. 2.2 Trims a) Copper Alloy b) Ferrous c) Stainless Steel d) Resilient or Non-Metallic 2.3 Classes a) Class 125 b) Class 250 2.4 Sizes a) 2 NPS 24 flanged end b) 2 NPS 6
30、threaded end 3. PRESSURE-TEMPERATURE RATINGS 3.1 Pressure-temperature ratings for the various classes of valves are shown in Table 1. SI (metric) units are shown in Table B1 of Annex B. The ratings specified are for valves with metal-to-metal seating surfaces. Pressure-temperature ratings for valves
31、 with non-metallic seat materials must be limited to reflect the physical characteristics of these materials at each temperature, and may be lower but in no case higher than valves shown in Tables 1 and B1. 3.2 The temperature shown for the corresponding rating shall be the metal temperature of the
32、pressure retaining parts. It shall be assumed 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 responsibility of the user. GRAY IRON SWING CHECK VALVES, FLANGED AND THREADED
33、ENDS MSS STANDARD PRACTICE SP-712 4. MATERIALS 4.1 General This Standard Practice covers minimum physical and chemical requirements. Materials of superior properties may be substituted. Users are cautioned against applications with fluids which may react chemically with any materials used in these v
34、alves. Consultation with the manufacturer is advised to determine suitability in cases of doubt. 4.1.1 Body and Cover The body and cover shall be in accordance with ASTM A126, Class B. 4.1.2 Seating Material Metal-to-Metal seating surfaces shall be brass or bronze for bronze mounted valves; gray iro
35、n or other ferrous material for all-iron valves. Non-metallic or resilient facing material shall be rubber (synthetic or natural), leather, or suitable polymer. Other seating materials, either metal or non-metallic, suitable for the intended service may be furnished when agreed between purchaser and
36、 manufacturer. 4.1.3 Hinge Pins Hinge pins shall be wrought brass or stainless steel for bronze mounted valves; wrought steel or stainless steel for all-iron valves. 4.1.4 Hinge Non-ferrous hinges shall not be used on all-iron valves. 4.1.5 Side Plugs Side plugs, if used, shall be made of gray iron,
37、 malleable iron, ductile iron, or steel. However, if used to support the hinge pin in bronze mounted valves, they shall be of brass, bronze, or brass or bronze bushed. 4.1.6 Bolting Bolts and studs connecting pressure containing parts shall develop physical strength not less than the requirements of
38、 ASTM A307, over the temperature range for which the valve is rated. 4.1.5 Bolting Bolts and studs connecting pressure containing parts shall develop mechanical properties not less than requirements of ASTM A307. 4.1.6 Glands Glands shall be made from brass, bronze, gray iron, or other ferrous mater
39、ial. TABLE 1 Pressure-Temperature Ratings, Non-Shock, psi CLASS 125 CLASS 250 Temperature (F) NPS 2 12 NPS 14 24 NPS 30 48 NPS 2 12 NPS 14 24 -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 10
40、5 355 230 350 150 100 335 220 375 145 315 210 400 140 290 200 425 130 270 450 125 250 Note: See Table B1 for SI (metric) units. MSS STANDARD PRACTICE SP-713 5. DESIGN 5.1 General When under the test pressure specified in Section 7, valves shall be designed to prevent permanent distortion of the body
41、, cover, disc, or seat. 5.2 Closure Assembly The closure assembly shall be designed to assume the closed position by gravity under no flow conditions in a horizontal pipeline. Special arrangements of levers and springs or weight may be necessary to assure proper closure in lines which are inclined o
42、r vertical. 5.3 Wall Requirements a) Valve bodies and covers shall meet the minimum wall thickness requirements specified in ASME B16.1 for the same NPS and Class gray iron fitting. b) Additional metal thickness needed, for example, for assembly loads, actuating (closing and opening) loads, shapes o
43、ther than circular, and stress concentrations, must be determined by individual manufacturers since these factors vary widely. In particular, intersections and openings in enlarged body cavities may require additional reinforcement to assure adequate strength and rigidity. 5.4 End Flanges a) End fla
44、nges shall be integral with the valve body. Dimensions, tolerances, and drilling shall be in accordance with ASME B16.1 for each respective pressure class. End flanges shall be machined in accordance with ASME B16.1 and shall have a surface finish in accordance with MSS SP-6. b) Face-to-face dimensi
45、ons of flanged end valves shall be as follows: Class 125, Full Waterway (Figures A1 and A2): 2 NPS 12 per ASME B16.10 14 NPS 24 per manufacturers specification Class 125, Clear Waterway (Figures A3 and A4): 2 NPS 24 per manufacturers specification Class 250, Full Waterway (Figures A1 and A2): 2 NPS
46、12 per ASME B16.10 14 NPS 18 per manufacturers specification 5.5 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 ASME B1.20.1. 5.6 Body-Cover Bolting a) Dimensions of bolts and cap screws sh
47、all be in accordance with ASME B18.2.1; nut dimensions in accordance with ASME B18.2.2. b) Nuts shall be threaded in accordance with ASME B1.1, Coarse Thread Series, Class 2B. c) Bolts, studs or cap screws shall be threaded in accordance with ASME B1.1, Coarse Thread Series, Class 2A. 5.7 Seating Su
48、rfaces 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 valve seats may be integral with the body casting at the manufacturers option. Driving lugs may protru
49、de into and reduce port area. 5.8 Bypass and Drain Connections Unless otherwise specified, bypass and drain connections shall be in accordance with MSS SP-45. MSS STANDARD PRACTICE SP-714 6. WORKMANSHIP 6.1 Valve Parts Valve parts shall be designed and manufacturing tolerances set so as to provide interchangeability 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 that may impair their
