MSS SP-132-2016 Compression Packing Systems for Instrument Valves.pdf

1、MSS SP-132-2016 Compression Packing Systems for Instrument 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: standards

2、msshq.org www.msshq.org MSS STANDARD PRACTICE SP-132i This MSS Standard Practice was developed under the consensus of the MSS Technical Committee 115 and the MSS Coordinating Committee. The content of this Standard Practice is the resulting efforts of competent and experienced volunteers to provide

3、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 does no

4、t 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, n

5、or 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 indicate

6、d 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 A). This Standard Practice shall remain silent on the valid

7、ity 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

8、 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 construe

9、d 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 requirement

10、s. Substantive changes or reformatting in this 2016 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 flagged with that in the previous edition. U.S. customary units in this SP are the stand

11、ard; the SI (metric) units are for reference only. Excerpts of this Standard Practice may be quoted with permission. Credit lines should read Extracted from MSS SP-132-2016 with permission of the publisher, Manufacturers Standardization Society of the Valve and Fittings Industry. Reproduction and/or

12、 electronic transmission or dissemination is prohibited under copyright convention unless written permission is granted by the Manufacturers Standardization Society of the Valve and Fittings Industry Inc. All rights reserved. Originally Approved: August 2004 Originally Published: October 2004 Curren

13、t Edition Approved: August 2016 Current Edition Published: November 2016 Copyright , 2016 by Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. Printed in U.S.A. MSS STANDARD PRACTICE SP-132ii TABLE OF CONTENTS SECTION PAGE 1 SCOPE . 1 2 DEFINITIONS 1 3 PACKING MATERIALS

14、1 4 DESIGN . 2 5 TESTING . 2 ANNEX A Referenced Standards and Applicable Dates 3 MSS STANDARD PRACTICE SP-1321 COMPRESSION PACKING SYSTEMS FOR INSTRUMENT VALVES 1. SCOPE 1.1 This Standard Practice provides requirements for valve packings, packing chambers, and associated components as they relate to

15、 the total packing assembly of instrumentation valves. 1.2 This Standard Practice is intended to apply to valves used in instrument piping systems (see MSS SP-99, Instrument Valves and MSS SP-105, Instrument Valves for Code Applications). 1.3 This Standard Practice applies to valves in which a compr

16、ession packing assembly is used as the primary stem sealing system. 2. DEFINITIONS 2.1 Packing The pressure retaining seal at the interface between the stem and the pressure containing boundary. 2.2 Terminology Other definitions may be found in MSS SP-96, Guidelines on Terminology for Valves and Fit

17、tings. 3. PACKING MATERIALS 3.1 Graphitic Packings 3.1.1 Applicable Grade Designations Ring Type Grade A Grade B Die Formed Braided - 3.1.2 Purity Requirements (min.) Material Grade A Grade B Graphitic 99% 95% Carbon (Braided only) 95% - 3.1.3 Detrimental Material Limits (max. ppm) Chemical Grade A

18、Grade B Mercury (Hg) 200 200 Sulfur (S) 750 1000 Total halogens (Chlorine, bromine, fluorine)500 500 MSS STANDARD PRACTICE SP-1322 3.1.4 Prohibited Additions There shall be no intentional additions of antimony (Sb), arsenic (As), bismuth (Bi), cadmium (Cd), gallium (Ga), indium (In), lead (Pb), silv

19、er (Ag), or tin (Sn) during the manufacturing, fabrication, handling or packaging of the product. 3.1.5 Corrosion Inhibiting Treatments Unless specified to be free of corrosion inhibiting additives, graphitic packings may be provided with a powdered zinc (Zn) active corrosion inhibiting treatment an

20、d/or a passive inhibiting treatment such as phosphorus or barium molybdate. 3.2 Plastic Packings Acceptable materials include but are not limited to “virgin” PTFE (Polytetrafluoroethylene), PFA (Perfluoroalkoxy), PEEK (Polyetheretherketone), and UHMWPE (Ultra-High Molecular Weight Polyethylene), in

21、addition to filling variations thereof (e.g., glass-filled, carbon-filled, etc.). 4. DESIGN 4.1 General The design of packing systems shall be in accordance with the manufacturers standard and proof of design shall be documented. 4.2 Stems 4.2.1 Finish The stem surface finish shall have a roughness

22、average (Ra) of 16 micro inches (0.41 surface microns) or better. This is also expressed as Ra 16 in. (0.41 m). The stem surface finish requirement shall apply in the area that contacts the packing during the full stroking of the valve. 4.2.2 The stem outside diameter that contacts the packing durin

23、g the full stroking of the valve shall meet circularity, taper, and straightness requirements encompassed in a cylindricity tolerance of 0.001 in. (0.03 mm). 4.2.3 The stem surface that contacts the packing during full stroking of the valve shall be free of scratches, pits, or voids deeper than 0.00

24、05 in. (0.01 mm). 4.3 Packing Chambers 4.3.1 Finish The packing chamber surface finish shall be Ra 63 in. (1.6 m) or better through 80% of the bore with the remaining finish not to be greater than Ra 125 in (3.18 m). 4.3.2 Packing chamber surfaces that contact the packing shall be free of scratches,

25、 pits, or voids deeper than 0.001 in. (0.03 mm). 4.4 Recommended Design Considerations 4.4.1 The tolerance on the valve bonnet or the packing washer, when a packing washer is used, shall be such that the diametrical clearance between the stem and the bonnet or packing washer is no greater than 0.005

26、 in. (0.13 mm). 5. TESTING 5.1 Qualification Testing 5.1.1 Qualification testing requirements shall be per the manufacturers standard unless otherwise specified. 5.2 Production Testing 5.2.1 Production testing shall be conducted per MSS SP-99 or MSS SP-105, as applicable. MSS STANDARD PRACTICE SP-13

27、23 ANNEX A Referenced Standards and Applicable Dates This Annex is an integral part of this Standard Practice and is placed after the main text for convenience. Standard Name Description MSS; ANSI/MSS SP-96-2011 Guidelines on Terminology for Valves and Fittings SP-99-2016 Instrument Valves SP-105-20

28、16 Instrument Valves for Code Applications The following organization appears in the above list. MSS Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. 127 Park Street, NE Vienna, VA 22180-4602 Purchase or View a Full Listing of MSS Standards at: http:/msshq.org/Store/Pri

29、ceList.cfm MSS Standard Practices (SPs) related to or referenced in this publication: ANSI/MSS SP-96 Guidelines on Terminology for Valves and FittingsANSI/MSS SP-99 Instrument Valves MSS SP-105 Instrument Valves for Code Applications American National Standards Published by MSS, an ANSI-accredited S

30、tandards Developer:ANSI/MSS SP-25 Standard Marking System for Valves, Fittings, Flanges, and UnionsANSI/MSS SP-44 Steel Pipeline FlangesANSI/MSS SP-55 Quality Standard for Steel Castings for Valves, Flanges, Fittings, and Other Piping Components Visual Method for Evaluation of Surface Irregularities

31、ANSI/MSS SP-58 Pipe Hangers and Supports - Materials, Design, Manufacture, Selection, Application, and InstallationANSI/MSS SP-96 Guidelines on Terminology for Valves and Fittings ANSI/MSS SP-114 Corrosion Resistant Pipe Fittings Threaded and Socket Welding Class 150 and 1000ANSI/MSS SP-134 Valves f

32、or Cryogenic Service, including Requirements for Body/Bonnet ExtensionsANSI/MSS SP-135 High Pressure Knife Gate Valves ANSI/MSS SP-138 Quality Standard Practice for Oxygen Cleaning of Valves and FittingsANSI/MSS SP-144 Pressure Seal Bonnet Valves Do not violate copyright laws All Standard Practices

33、are officially available only from MSS and through our authorized distributors: About MSS The Manufacturers Standardization Society (MSS) of the Valve and Fittings Industry is a non-profit technical association organized for development and improvement of industry, national and international codes a

34、nd standards for Valves, Valve Actuators, Valve Modifications, Pipe Fittings, Flanges, Pipe Hangers and Supports, and Associated Seals. Since its establishment in 1924, MSS has been dedicated to developing standards for national and global applications, in cooperation with other standardizing bodies

35、 and regulatory authorities. For more information on membership and eligibility requirements, visit: http:/msshq.org/Store/Membership.cfm Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. 127 Park Street, NE, Vienna, VA 22180-4620 Phone (703) 281-6613 Fax (703) 281-6671 “The Technical Voice of the Industry” IHS MSS SP-132-2016