1、MSS SP-155-2018 Plastic-Lined Metal Valves Standard Practice Developed and Approved by the Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. 127 Park Street, NE Vienna, Virginia 22180-4602 Phone: (703) 281-6613 Fax: (703) 281-6671 E-mail: standardsmsshq.org www.msshq.org
2、 MSS STANDARD PRACTICE SP-155i This MSS Standard Practice was developed by a Special Task Group under the consensus of the MSS Technical Committee 304, Quality Standards, and the MSS Coordinating Committee. A permanent committee will be determined for future maintenance of this Standard Practice. Th
3、e 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 p
4、ractice 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
5、other 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 a
6、ttributable 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
7、of approval of this MSS Standard Practice (see Annex A). 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.” Informational references that may be helpful to the user in the
8、application of this Standard Practice are listed in Appendix X1. 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 not be held responsible for identifying any patent rights.
9、 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 to be essential to the understanding of the message of th
10、e 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. U.S. customary units in this Standard Practice are the st
11、andard; the SI (metric) units are for reference only. Combining or converting values between the two systems may result in non-conformance with this Standard Practice. Non-toleranced dimensions in this Standard Practice are nominal unless otherwise specified. Excerpts of this Standard Practice may b
12、e quoted with permission. Credit lines should read Extracted from MSS SP-155-2018 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 w
13、ritten permission is granted by the Manufacturers Standardization Society of the Valve and Fittings Industry Inc. All rights reserved. Originally Approved: March 2018 Originally Published: May 2018 MSS is a registered trademark of Manufacturers Standardization Society of the Valve and Fittings Indus
14、try, Inc. Copyright , 2018 by the Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. Printed in U.S.A. MSS STANDARD PRACTICE SP-155ii This Page Intentionally Left Blank Manufacturers Standardization Society of the Valve and Fittings Industry MSS STANDARD PRACTICE SP-155ii
15、i TABLE OF CONTENTS SECTION PAGE 1 SCOPE AND FIELD OF APPLICATION 1 2 DEFINITIONS . 1 3 MATERIALS . 1 4 REQUIREMENTS . 2 5 QUALIFICATION REQUIREMENTS . 4 6 INSPECTION TESTS 5 7 FINISH . 6 8 MARKING . 6 9 PACKAGING 6 TABLE 1 Specification Coverage (preferred liner materials) . 7 2 Liner Material Temp
16、erature Specifications 7 3 Liner Standard Specifications and Mechanical Properties 8 4 Preferred Materials for Housing, Cap, Ball/Plug/Disc . 8 5 Preferred Materials for Stem 9 6 Lining Flare Diameter 9 FIGURE 1 Lining Flare Diameter and Weep Hole Location 3 2 Weep Holes . 3 ANNEX A Referenced Stand
17、ards and Applicable Dates 10 APPENDIX XI Informational Standards . 12 MSS STANDARD PRACTICE SP-155iv This Page Intentionally Left Blank Manufacturers Standardization Society of the Valve and Fittings Industry MSS STANDARD PRACTICE SP-1551 PLASTIC-LINED METAL VALVES 1. SCOPE AND FIELD OF APPLICATION
18、1.1 This Standard Practice covers factory-made plastic-lined metal valves intended primarily for conveying corrosive fluids. Requirements for materials, workmanship, dimensions, design, fabrication, working pressure and temperatures, test methods, qualification requirements, and markings are include
19、d within this Standard Practice. 1.1.1 This Standard Practice does not define the suitability of different liner materials to various chemical and operating environments. Refer to the manufacturers chemical resistance data for suitability recommendations. 1.1.2 This Standard Practice does not includ
20、e products coated with plastics. 1.1.3 This Standard Practice applies to ball, check, plug, butterfly, and similar quarter-turn valves. It does not apply to diaphragm or plastic-lined knife gate valves. 1.2 This Standard Practice covers plastic-lined valves with preferred liner materials as listed i
21、n Table 1. 1.3 This Standard Practice does not include urethane and polyurethane liner materials, which are typically applied for abrasion resistance. 2. STANDARD UNITS 2.1 General The definitions used are in accordance with terminologies found in ASTM F412, ASTM D1600, and MSS SP-96, unless otherwi
22、se indicated. 3. PRESSURE-TEMPERATURE RATINGS 3.1 Lining 3.1.1 The standard specifications and corresponding general mechanical properties of the preferred liner materials are listed in Table 3. Mechanical properties of the liner material in plastic-lined metal valves may deviate from the standard s
23、pecification due to manufacturers designs. 3.1.2 Only virgin material shall be used unless agreed upon by manufacturer and purchaser. 3.1.3 No pigmentation shall be used unless agreed upon by manufacturer and purchaser. 3.2 Housing (Bodies), Cap, Ball/Plug/Disc, Stem, Pistons, and Poppets 3.2.1 Mech
24、anical Properties Housings (Bodies), Caps, and Balls/Plugs/Discs The mechanical properties of the housings (bodies), caps, and balls/plugs/discs shall conform to the appropriate specifications listed in Table 4; except as they are influenced by accepted methods of processing in the industry. Table 4
25、 is not an exhaustive list, and other materials may be substituted by agreement between manufacturer and purchaser. 3.2.2 Mechanical Properties Stems The mechanical properties of the stems shall conform to the appropriate specifications listed in Table 5, except as they are influenced by accepted me
26、thods of processing in the industry. Table 5 is not an exhaustive list, and other materials may be substituted by agreement between manufacturer and purchaser. Lined ball-stem, plug-stem, and disc-stem materials shall meet the mechanical properties of the valve design. MSS STANDARD PRACTICE SP-1552
27、3.3 Seats and Seals Seat and seal material shall be based on service fluids and required properties for the valve design. The most commonly used material for seats and seals of ball valves is Polytetrafluoroethylene (PTFE). The standard specifications and corresponding general mechanical properties
28、of PTFE materials (a)are: Standard Resin Specification: ASTM D1457 ASTM D4894 ASTM D4895 Minimum Tensile Strength at Break: 3000 psi (20.7 MPa) Minimum Elongation at Break: 250% 4. REQUIREMENTS 4.1 Dimensions 4.1.1 Housing/Body Housing/body installation dimensions are as required in the applicable m
29、aterial specification in accordance with Section 4.1.2. 4.1.2 Flanges The flanges of plastic-lined valves shall conform dimensionally to ASME B16.5. The face-to-face dimensions include the plastic lining and shall conform to ASME B16.10. 4.1.3 Plastic Wall Thickness Valve liners shall have a minimum
30、 wall thickness and thickness at flange face of 0.100 in. (2.54 mm). 4.1.4 Lining Flare Diameter The outside diameter of the flare covering the gasket portion of the flange shall not be less than the diameter specified in Table 6. Requirements for minimum flare diameters, as defined in ASTM F1545, m
31、ay be applied upon agreement between manufacturer and purchaser. The flared portion of the lining shall be concentric with the flared portion of the pipe within 116 in. (1.6 mm). See example illustrated in Figure 1. 4.1.5 Tolerances The tolerances of the flanges of plastic-lined valves shall conform
32、 to ASME B16.5. The tolerances of the face-to-face dimensions include the plastic lining and shall conform to ASME B16.10. 4.2 Liner Anchoring When the housing/body uses a molded-in liner design (i.e., ball and plug), the housing/body shall include geometries for liner anchoring. These geometries sh
33、all fix the liner in both the axial/flow direction and in the radial direction. The quantity and the locations of these liner anchoring geometries shall be defined by manufacturer to ensure the proper fixation of the liner in all areas of the valve. 4.3 Stem Blow-Out If the valve design includes a s
34、eparate stem to operate the valve, the stem design shall be blow-out proof. 4.4 Weep Holes Weep holes, should they be requested, shall be drilled and tapped prior to the liner installation. Weep holes shall be tapped and threaded as NPS 1/4 (DN 8), with Female (internal) National Pipe Thread (FNPT)
35、per ASME B1.20.1. In addition, the weep hole shall be located within 30 degrees of the nominal bottom center line, as close to a flange as possible without interfering with the flange fasteners. See examples illustrated in Figure 1 and Figure 2. 4.5 Welding All metal welding shall be performed by ce
36、rtified welders or welding operators in accordance with the ASME Boiler and Pressure Vessel Code, Section IX. No welding shall be done on lined components in the field. NOTE: (a) The PTFE in plastic-lined metal valves can deviate from the standard specification due to manufacturers designs. MSS STAN
37、DARD PRACTICE SP-1553 FIGURE 1 Lining Flare Diameter and Weep Hole Location FIGURE 2 Weep Holes MSS STANDARD PRACTICE SP-1554 4.6 Pressure Limitations As indicated in Section 1.2, this Standard Practice covers plastic-lined valves with preferred liner materials as listed in Table 1. However, pressur
38、e limitations shall be in accordance with ASME B16 Standards (B16.1, B16.5, B16.34, and B16.42) to which the valve is designed and documented by the manufacturer; except reduced pressure limitations may be established by the manufacturer, after considering both pressure and temperature limitations (
39、a)of the metal housing and the sealing ability of the liner. 4.7 Temperature Limitations (a)The temperature rating of the valve should not exceed the maximum or minimum allowable lining material rating as shown in Table 2. In some cases, valve design and configuration may lead to a temperature ratin
40、g below maximum or above minimum of these values. Purchasers should consult with manufacturers as to the likely result of using a particular lined metal valve component at temperatures outside these specified ranges. 4.8 Safety Considerations It is the responsibility of the user of this Standard Pra
41、ctice to establish and employ appropriate safety and health practices, and to determine the applicability of regulatory requirements and limitations prior to use. 4.9 Workmanship 4.9.1 Housing, body, cap, and lining shall show no evidence of pinholes, porosity, or cracks when inspected in accordance
42、 with Section 4.9.2. The linings shall fit snugly inside the fitting housings. Any bulges or other obvious indications of poor contact with the housing shall be cause for rejection. 4.9.2 The gasket seating surface of the lining shall be free of surface defects that could impair sealing effectivenes
43、s. Scratches, dents, nicks, or tool marks on the seating surface shall not be deeper than 10% of the face thickness. Size, shape, density, and separation of defects is dependent on the size of valve and gasket sealing surface area, and subject to agreement between manufacturer and purchaser. 4.10 Pe
44、rformance 4.10.1 Qualification Lined valves must be capable of meeting the qualification requirements specified in Section 5. 4.10.2 Inspection Each valve, prior to shipment, shall be tested in accordance with Section 6 and shall subsequently be inspected visually to verify conformance to the requir
45、ements of Section 4.9. 5. QUALIFICATION REQUIREMENTS 5.1 Service Pressure Ratings The pressure-temperature rating of flanged and wafer valves shall conform to the standards listed within this section, except as they are limited by their seat, seal and lining materials and/or manufacturers recommenda
46、tions. 5.1.1 Carbon Steels, Alloy Steels, Stainless Steels, Duplex Steels, and Nickel Alloys: ASME B16.5 and ASME B16.34 (Groups 1,2, and 3) 5.1.2 Ductile Iron: ASME B16.42 5.1.3 Gray Iron: ASME B16.5.1.4 Copper Alloy: ASME B16.24 NOTE: (a) The temperature limitations are based on noncorrosive test
47、conditions. Use in specific aggressive environments may alter temperature limitations. In such instances, specific temperature limits shall be established by mutual agreement between the purchaser and the manufacturer. MSS STANDARD PRACTICE SP-1555 5.2 Cold Working Pressure (CWP) The cold working pr
48、essure rating of the valve shell and components is the rated pressure at 100 F (38 C) for carbon steel, alloy steel, stainless steel, and ductile iron. The maximum working pressure at any other temperature shall not exceed ASME B16.34, ASME B16.42, ASME B16.24, or ASME B16.1 rated pressure, dependin
49、g on the housing/body temperature, and the standard to which the valve is designed and documented by the manufacturer. 5.3 Valve Port Sizes The valves may be furnished as either full port, regular port, or reduced port. Where linings, liners, or cartridges are used to form portions or all of the flow passages, the inside diameter shall be that of the lining-body, liner-body, or cartridge-body interface. 5.4 Valve Operation The manufacturer should specify the method of operation and the Maximum Differential Pressure (MDP) at which the valve is required to be open
