1、 MSS SP-70-2011 Gray Iron Gate Valves, Flanged and Threaded EndsStandard 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: infomss-hq.
2、org MSS www.mss-hq.org MSS STANDARD PRACTICE SP-70i 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 provide an
3、 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 does not
4、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 power, nor
5、 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 indicated
6、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 validit
7、y 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 shall n
8、ot 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 construed
9、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 requirements.
10、 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 material
11、 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 MSS SP-70-
12、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 Society of
13、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 Manufacturers Standardization Society of the Valve and Fittings
14、 Industry, Inc. Copyright , 2011 by Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. Printed in U.S.A. MSS STANDARD PRACTICE SP-70ii FOREWORD The 1998 edition of MSS SP-70, in addition to various editorial changes, includes changes to: provide a more complete metric ver
15、sion for reference use, delete the Class 800 Pressure-Temperature rating, and expand Annex C to include ISO references. The 2006 edition of MSS SP-70 included the following changes: 1) deleted ASTM A536 and ASTM A395 materials, since valves made of these materials will now be included in SP-128; 2)
16、deleted PN designations since these were easily confused with designations used in international standards that were based on other material specifications and pressure-temperature rating procedures; 3) deleted DN designations in Table B1 resulting from PN deletion; 4) ISO references were deleted fr
17、om Annex C as a result of change 2 and 3 above; 5) added minimum wall thickness requirements, that were previously omitted, in order to qualify the Class 125 and Class 250 ratings designations used in this Standard Practice; 6) added Type IV valves with illustrations; and 7) replaced the terminology
18、 “cast” iron with “gray” iron. This 2011 edition of MSS SP-70, in addition to various editorial and formatting updates, includes changes to: (1) revise Section 4.1.4 by adding “gray iron” as an acceptable handwheel material; (2) clarify the leakage rate in Section 7.4; and (3) update the organizatio
19、ns and references in Annex C. MSS STANDARD PRACTICE SP-70iii TABLE OF CONTENTS SECTION PAGE 1 SCOPE . 1 2 VALVE DESIGNATION, CLASSES, AND SIZES . 1 3 PRESSURE-TEMPERATURE RATINGS . 1 4 MATERIALS . 2 5 DESIGN . 2 6 WORKMANSHIP . 4 7 TESTS 4 8 MARKING 5 9 PAINTING . 5 TABLE 1 Pressure-Temperature Rati
20、ngs, Non-Shock, psi 2 2 Shell Test Pressure, Minimum . 4 3 Test Duration, Minimum . 5 B1 Pressure-Temperature Ratings, Non-Shock, bar 10 FIGURE A1 Rising Stem, Solid-Wedge Gate Valve, Type I 6 A2 Non-Rising Stem, Solid-Wedge Gate Valve, Type I 6 A3 Rising Stem, Split-Wedge Gate Valve, Type II . 7 A4
21、 Non-Rising Stem, Split-Wedge Gate Valve, Type II . 7 A5 Rising Stem, Double-Disc, Parallel Seat Gate Valve, Type III 8 A6 Non-Rising Stem, Double-Disc, Parallel Seat Gate Valve, Type III 8 A7 Rising Stem, Resilient Wedge Gate Valve, Type IV 9 A8 Non-Rising Stem, Resilient Wedge Gate Valve, Type IV
22、. 9 ANNEX A Valve Types Figures A1 through A8 6 B SI (Metric) Units . 10 C Referenced Standards and Applicable Dates 11 MSS STANDARD PRACTICE SP-701 1. SCOPE 1.1 This Standard Practice covers gray iron gate valves with flanged or threaded ends. 1.2 This Standard Practice covers valves in sizes and p
23、ressure-temperature ratings specified herein for general purpose service. 1.3 This Standard Practice also includes, directly or by reference, stipulations on chemical and physical properties of materials, and dimensions of end connections in common use. 2. VALVE DESIGNATION, CLASSES, AND SIZES 2.1 V
24、alve Types Valve types covered herein are illustrated in Figures A1, A2, A3, A4, A5, A6, A7 and A8 in Annex A (1). Type I Solid Wedge Disc (See Figures A1 and A2) Type II Split Wedge Disc (See Figures A3 and A4) Type III Double Disc, Parallel Seat (See Figures A5 and A6) Type IV Resilient Seat (See
25、Figures A7 and A8) 2.2 Construction Designations Designation: NT Non-Rising Stem, Threaded End NF Non-Rising Stem, Flanged End OT Outside Screw and Yoke, Threaded End OF Outside Screw and Yoke, Flanged End Note: (1) The figures in Annex A are for the purpose of illustration and nomenclature only. Th
26、ey are not intended to exclude any design meeting this Standard Practice. 2.3 Trims (a) All Bronze (b) All Iron (c) Bronze with Ferrous Stem (d) Resilient Seating 2.4 Classes 125 250 2.5 Sizes (a) 2 NPS 48 flanged end (b) 2 NPS 6 threaded end 3. PRESSURE-TEMPERATURE RATINGS 3.1 Pressure-temperature
27、ratings for the various classes of valves are shown in Table 1. SI (metric) units are shown in Table B1 in Annex B. The ratings specified are for valves with metal-to-metal seating surfaces. Pressure-temperature ratings for valves with non-metallic seat materials shall be limited to reflect the phys
28、ical characteristics of these materials at each temperature, and may be lower but in no case higher than the values shown in Tables 1 and B1. 3.2 The temperature shown for the corresponding rating shall be the metal temperature of the pressure retaining parts. It shall be assumed that the metal temp
29、erature 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 GATE VALVES, FLANGED AND THREADED ENDS MSS STANDARD PRACTICE SP-702 4. MATERIALS 4.1 General This Standard
30、 Practice covers minimum physical and chemical requirements. Users are cautioned against applications with fluids that may react chemically with any material used in these valves. Consultation with the manufacturer is advised to determine suitability in cases of doubt. 4.1.1 Body and Bonnet Body and
31、 Bonnet shall be gray iron 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 iron or other ferrous material for all-iron valves. Other materials suitable for the intended service may be furnished whe
32、n agreed upon between purchaser and manufacturer. 4.1.3 Stems Stem material shall be brass or bronze, either cast or wrought for bronze mounted valves, or wrought steel for all-iron valves. 4.1.4 Handwheels Handwheels may be gray iron, ductile iron, malleable iron or steel at the manufacturers optio
33、n. 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 material. 5. DESIGN 5.0 General When under the test pressure specified i
34、n Section 7, valves shall be designed to prevent permanent distortion of the body, bonnet, or seat. Valve stems shall be designed to prevent permanent distortion when the valve is operated at full rated working pressure. 5.1 Minimum Wall Requirements Valves bodies and bonnets shall meet the minimum
35、wall thickness requirements specified in ASME B16.1 for the same NPS and Class gray iron fitting. 5.2 End Flanges End flanges shall be integral with the valve body. Dimensions, tolerances and drilling shall be in accordance with ASME B16.1 for each NPS and respective pressure class and shall have a
36、surface finish in accordance with MSS SP-6. TABLE 1 Pressure-Temperature Ratings, Non-Shock, psi Temperature (F) CLASS 125 CLASS 250 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 39
37、5 250 300 165 110 50 375 240 325 155 105 355 230 350 150 100 335 220 375 145 315 210 400 140 290 200 425 130 270 450 125 250 Note: See Table B1 for SI (metric) units. MSS STANDARD PRACTICE SP-703 5.3 Face-to-face dimensions Face-to-face dimensions of flanged end valves shall be as follows: Class 125
38、 Solid or Split Wedge 2 NPS 24 per ASME B16.10 30 NPS 48(1)Double Disc (Parallel Seat) 2 NPS 12 per ASME B16.10 14 NPS 18(1)Class 250 Solid or Split Wedge ANSI/ASME B1.1-2003 (R2008) Unified Inch Screw Threads, (UN and UNR Thread Form) B1.20.1-1983 (R2006) Pipe Threads, General Purpose (Inch) B16.1-
39、2010 Gray Iron Pipe Flanges and Flanged Fittings: Classes 25, 125, and 250 B16.10-2009 Face-to-Face and End-to-End Dimensions of Valves B18.2.1-2010 Square, Hex, Heavy Hex, and Askew Head Bolts and Hex, Heavy Hex, Hex Flange, Lobed Head, and Lag Screws (Inch Series) B18.2.2-2010 Nuts for General App
40、lications: Machine Screw Nuts, Hex, Square, Hex Flange, and Coupling Nuts (Inch Series) ASTM Standard Specification for: A126-04(2009) Gray Iron Castings for Valves, Flanges, and Pipe Fittings A307-10 Carbon Steel Bolts and Studs, 60 000 psi Tensile Strength MSS SP-6-2007 Standard Finishes for Conta
41、ct Faces of Pipe Flanges and Connecting-End Flanges of Valves and Fittings SP-25-2008 Standard Marking System for Valves, Fittings, Flanges, and Unions SP-45-2003 (R 2008) Bypass and Drain Connections The following organizations appear in the above list: ANSI American National Standards Institute 25
42、 West 43rdStreet, Fourth Floor New York, NY 10036-7406 ASME American Society of Mechanical Engineers (ASME International) Three Park Avenue New York, NY 10016-5990 ASTM ASTM International 100 Bar Harbor Drive, P.O. Box C700 West Conshohocken, PA 19428-2959 MSS Manufacturers Standardization Society o
43、f the Valve and Fittings Industry, Inc. 127 Park Street, NE Vienna, VA 22180-4602 Listing of MSS Standard Practices TITLE SP-6-2007 Standard Finishes for Contact Faces of Pipe Flanges and Connecting-End Flanges of Valves and Fittings SP-9-2008 Spot Facing for Bronze, Iron and Steel Flanges SP-25-200
44、8 Standard Marking System for Valves, Fittings, Flanges, and Unions SP-42-2009 Corrosion Resistant Gate, Globe, Angle and Check Valves with Flanged and Butt Weld Ends (Classes 150, 300 however, the contents of these “historical” SPs are now part of newly revised SP-58-2009. MSS is an ANSI-accredited
45、 American National Standards developer. A number of former MSS Standard Practices have been adopted and published by other developers as American National Standards. In order to maintain a single source of authoritative information, MSS has withdrawn its Standard Practices in such cases. Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. 127 Park Street, NE, Vienna, VA 22180-4620 (703) 281-6613 Fax # (703) 281-6671 MSS SP-70-2011
