1、ANSI/MSS SP-144-2013 Pressure Seal Bonnet ValvesStandard 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: standardsmss-hq.org www.mss
2、-hq.org MSS STANDARD PRACTICE SP-144i This MSS Standard Practice was developed under the consensus of the MSS Technical Committee 114 and the MSS Coordinating Committee. In addition, this Standard Practice was approved by an ANSI/MSS Consensus Committee and ANSI as an American National Standard. The
3、 content of this Standard Practice is the resulting efforts of competent and experienced volunteers to provide 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 pr
4、actice 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 to this Standard Practice is established only by reference in o
5、ther documents such as a code, specification, sales contract, or public law, as applicable. MSS has no power, 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 at
6、tributable to MSS and is solely the responsibility of the certifier or maker of the statement. “Unless indicated 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 o
7、f approval of this MSS Standard Practice (see Annex B). This Standard Practice shall remain silent on the 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 wi
8、th respect to the validity of any potential claim(s) or of any patent rights in connection therewith. MSS 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 re
9、sponsibility. In this Standard Practice, all text, notes, annexes, tables, figures, and references are construed 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 docu
10、ment are construed as “supplemental”. Note that supplemental information does not include mandatory requirements. U.S. customary units in this Standard Practice are the standard; (SI) metric units are for reference only. Excerpts of this Standard Practice may be quoted with permission. Credit lines
11、should read Extracted from ANSI/MSS SP-144-2013 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 th
12、e Manufacturers Standardization Society of the Valve and Fittings Industry Inc. All rights reserved. Originally Approved: September 2012 Originally Published: February 2013 Current ANSI/MSS Edition Approved by ANSI: October 2015 Current ANSI/MSS Edition Published: October 2015 MSS is a registered tr
13、ademark of Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. Copyright 2013, 2015 by Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. Printed in U.S.A. MSS STANDARD PRACTICE SP-144ii TABLE OF CONTENTS SECTION PAGE 1 SCOPE . 1 2 DEFINITIONS .
14、 1 3 CLASS/SIZE DESIGNATION 2 4 CONSTRUCTION . 2 5 MATERIALS . 2 6 DESIGN . 3 7 MARKING . 7 TABLE 1 Minimum Stem Diameters for API 600 Style A, Pressure Seal Bonnet Gate Valves 9 FIGURE 1 Pressure Seal Bonnet 8 ANNEX A Pressure Seal Bonnet Gate Valve Nomenclature 10 B Referenced Standards and Applic
15、able Dates 12 MSS STANDARD PRACTICE SP-1441 1. SCOPE 1.1 This Standard Practice covers construction requirements for steel and alloy valves having pressure seal bonnets in the size range of NPS 2 (DN 50) through NPS 50 (DN 1250) and Pressure Classes 600, 900, 1500, 2500, and 4500. This Standard Prac
16、tice applies to gate, globe, and check valves and may be used in conjunction with other valve-specific standards; including the following identified in this Standard Practice as parent valve standards: API 594, Check Valves; Flanged, Lug, Wafer, and Butt-welding API 600, Steel Gate Valves Flanged an
17、d Butt-welding Ends, Bolted Bonnets API 603, Corrosion-resistant, Bolted Bonnet Gate Valves Flanged and Butt-welding Ends API 623, Steel Globe Valves Flanged and Butt-welding Ends, Bolted Bonnets ASME B16.34, Valves-Flanged, Threaded, and Welded End 1.2 For parent valve standard, API 600, this Stand
18、ard Practice covers two styles of pressure seal bonnet valves as follows: a. Style A valves in accordance with API 600, except modified with ASME B16.34 minimum wall thicknesses, smaller diameter seats and stems, and pressure seal bonnet requirements of this Standard Practice. b. Style B valves in a
19、ccordance with API 600, except as modified for pressure seal bonnet requirements of this Standard Practice. 1.3 Except for the requirements for modification to pressure seal bonnets and Style A gate valve modifications, and Style B gate valve specific details, the requirements of this Standard Pract
20、ice are not intended to replace requirements of the parent valve standard. In the event of a discrepancy between this Standard Practice and a governing normative standard affecting valve construction besides the pressure seal, then the governing normative standard shall take precedence. 1.4 Stop che
21、ck valves shall be constructed to the requirements of a globe valve parent valve standard except as modified for pressure seal bonnet requirements of this Standard Practice. 1.5 This Standard Practice includes additional construction detail requirements specifically related to parent standard valves
22、 modified with pressure seal bonnets. 1.6 Annex A illustrates pressure seal bonnet gate valves and a typical pressure seal bonnet detail for the purposes of identifying nomenclature used in this Standard Practice for valve parts. 2. DEFINITIONS 2.1 General Definitions given in MSS SP-96 apply to thi
23、s Standard Practice. 2.2 Construction An all-inclusive term comprising materials, design, fabrication, examination, testing, inspection, and certification required in the manufacture and installation of a valve. 2.3 Parent Valve Standard This Standard Practice endorses the referenced valve standard
24、construction requirements but has additional construction detail requirements not addressed by the referenced parent valve standard. 2.4 Pressure Seal Gasket The pressure sealing part of a pressure seal joint. 2.5 Pressure Seal Bonnet A valve bonnet closure assembly in which internal fluid pressure-
25、force on the bonnet increases the compressive loading on the sealing gasket creating a self-sealing closure. 2.6 Segmental Retaining Ring A sectioned metallic ring (two or more parts) used in a pressure seal valve bonnet design to retain the valve bonnet/gasket structure from disengaging from the va
26、lve body (see Annex A). PRESSURE SEAL BONNET VALVES MSS STANDARD PRACTICE SP-1442 2.7 Spacer Ring (Thrust Ring) An interface ring used between the segmental retaining ring or gasket retention device and gasket of a pressure seal joint (see Annex A). 3. CLASS/SIZE DESIGNATION 3.1 Pressure Rating Desi
27、gnation “Class”, followed by a dimensionless number, is the designation for ASME B16.34 pressure-temperature ratings. Standardized Class designations used in this Standard Practice are as follows: Class 600 900 1500 2500 45003.2 Size “NPS”, followed by a dimensionless number, is the designation for
28、“nominal pipe size”. NPS is related to the reference “nominal diameter”/”diameter nominal” or DN, which is used in international standards. The relationship is, typically, as follows: NPS DN 2 50 21/265 3 80 4 100 For NPS 4, the related DN = 25 multiplied by the NPS number. 4. CONSTRUCTION The const
29、ruction requirements for pressure seal bonnet valves shall be in accordance with the applicable requirements of the parent valve standard except as required by this Standard Practice for pressure seal valve bonnet joint construction requirements and API 600 Type A and B gate valve modifications. Cer
30、tification or compliance marking to the parent valve standard may be altered by the pressure seal bonnet requirements of this Standard Practice and is not required. 5. MATERIALS 5.1 Body and Bonnet The valves body and bonnet material shall be an ASME B16.34 Group 1, Group 2, or Group 3 material as r
31、equired by the parent valve standard and specified in a purchase order. 5.2 Gasket The pressure seal gasket material shall be the manufacturers standard, but be limited to a ductile iron, soft steel, austenitic stainless steel, vermiculite or flexible graphite material. Flexible graphite gaskets sha
32、ll be provided with a corrosion inhibitor. Metal gaskets may be plated with a corrosion resistant and/or seal enhancement coating at the option of the manufacturer. The size, shape and profile of gasket shall be at the option of the valve manufacturer. When a graphite or vermiculite gasket is used,
33、additional consideration shall be given to the diametrical clearances between the body and bonnet, between the body and spacer ring and between the bonnet and spacer ring so as to minimize extrusion. When a flexible graphite gasket is used, the gasket may have an upper and lower corrosion resistant
34、metal device to protect the graphite from excessive bearing load extrusions and from oxidation. Other flexible graphite gasket designs may be used but the gasket and/or joint shall be designed to limit corrosion, extrusion and oxidation. 5.3 Retention/Sealing Device The pressure seal bonnet retentio
35、n/sealing combination shall be the manufacturers standard based on a tested and proven design. The material for the retention/sealing device (inserted segmental retaining ring, threaded or bolted device) shall have an allowable stress, for the valves full temperature range, commensurate with the val
36、ve bodys pressure temperature rating at all temperatures. The wetted metal part materials of the pressure seal joint shall have a corrosion resistance at least equivalent to that of the valve body material. 5.4 Hardfacing API 600 Style A and B gate valve hardfacing shall be a CoCr-A alloy, as requir
37、ed by Table 8 of API 600. Unless a hardfacing alloy is specified by the parent valve standard, the material shall be at the option of the manufacturer. 5.5 Stainless Steel Overlay Unless otherwise specified, pressure seal bonnet API 600 Style B gate valves made from B16.34, Group 1 materials, shall
38、have a machined 300-series stainless steel overlay on the body at the pressure seal gasket MSS STANDARD PRACTICE SP-1443 sealing contact area. Unless specified by the purchase order, API 600 Style A gate and other parent standard pressure seal gate, globe, and check valves made of ASME B16.34 Group
39、1 materials with a 300-series stainless overlay, shall be at the option of the manufacturer. 5.6 Bolting Material Bonnet adjustment bolting material shall be selected, or the bolting shall be coated, to provide continuous serviceability during the valves service life. 6. DESIGN 6.1 The thickness of
40、the body wall of the API 600 Style A pressure seal bonnet gate valve shall conform to the requirements of ASME B16.34. 6.2 The inside diameter of the seat opening of API 600 Style A pressure seal bonnet gate valves shall not be less than 90 percent of that specified in Appendix A of B16.34 for the v
41、alves nominal pipe size and pressure class. 6.3 ASME B16.34 Standard Pressure Class valves are the standard under this Standard Practice. ASME B16.34 Special Class butt-welding end valves may be supplied for API 600 Style A or Style B gate valves by agreement with the purchaser. 6.4 For API 600 Styl
42、e A and B gate valves, the body seat surfaces shall be of hardfaced material (see Section 5.4) that is weld deposited on either separate seat ring(s) welded into the body, or directly onto the body. The minimum finished thickness of the hardfacing material shall be 0.06 inches (1.6 millimeters). Gat
43、e valve seat surfaces shall be finished with a chamfer or radius on the outside and inside dimensions. 6.5 The minimum thickness of the bonnet wall of the API 600 Style A pressure seal bonnet gate valve shall conform to the requirements of ASME B16.34. 6.6 For API 600 Style A and B gate valves, the
44、bonnet backseat shall be a bushing welded at the stem hole or an integral weld deposit. The backseat seating surface shall be a hardface material in accordance with Section 5.4. Weld deposited backseat facings shall have a minimum finished thickness of 0.06 in. (1.6 mm). 6.7 For API 600 Style B pres
45、sure seal bonnet gate valves, a double disc gate is not permitted, unless otherwise specified in the purchase order. 6.8 For API 600 Style A pressure seal bonnet gate valves, if a wedge gate is used, a flexible wedge shall be furnished in sizes NPS 6 (DN 150) and larger, unless otherwise specified i
46、n the purchased order. 6.9 For API 600 Style A and B gate valves, the gate and body shall have guide surfaces to minimize wear of seats during normal operation of the valves and to ensure the alignment of the gate and stem during full travel and in all orientations. The possible loss of metal due to
47、 corrosion, erosion, and abrasive wear or a combination of these factors shall be considered in the design of both the gate and the body guide surfaces. In addition, the discs in a parallel double-disc gate seated valve may be in contact with the seats during the full travel of the gate. 6.10 API 60
48、0 Style A and B gate seating surfaces shall be weld deposited hardfacing material meeting Section 5.4 and having a minimum finished thickness of 0.06 in. (1.6 mm). 6.11 For API 600 Style A pressure seal gate valves, the minimum stem diameters shall be in accordance with Table 1. 6.12 The pressure se
49、al body-to-bonnet joint shall be designed and constructed such that the effective seal force shall increase as internal pressure increases. 6.13 The pressure seal bonnet shall have a bolting adjustment mechanism to pre-compress the gasket to allow parent valve standard production tests to proceed. The size of the adjustment bolting shall accommodate the pre-compression load requirement. The bolting size shall also support the bonnet from MSS STANDARD PRACTICE SP-1444 frictional stem/packing forces during opening and closing operation and protect the bonnet/gasket seal
