MSS SP-61-2013 Pressure Testing of Valves.pdf

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1、 MSS SP-61-2013 Pressure Testing of 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: standardsmss-hq.org www.mss-hq.o

2、rg MSS MSS STANDARD PRACTICE SP-61 i This MSS Standard Practice was developed under the consensus of the MSS Technical Committee 114 and the MSS Coordinating Committee. The content of this Standard Practice is the resulting efforts of competent and experienced volunteers to provide an effective, cle

3、ar, 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 in itself precl

4、ude 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 does it undert

5、ake, 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 otherwise withi

6、n 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 validity of those othe

7、r 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 not be held resp

8、onsible 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 to be essential

9、 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. U.S. customary

10、 units in this Standard Practice are the standard; (SI) metric units are for reference only. Substantive changes in this 2013 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 t

11、hat in the previous edition. Non-toleranced dimensions in this Standard Practice are nominal unless otherwise specified. Excerpts of this Standard Practice may be quoted with permission. Credit lines should read Extracted from MSS SP-61-2013 with permission of the publisher, Manufacturers Standardiz

12、ation 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 the Valve and Fittings Industry Inc. All rights reserved. Origi

13、nally Published: February 1961 Current Edition Approved: December 2012 (Updated April 2013) Current Edition Published: May 2013 MSS is a registered trademark of Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. Copyright , 2013 by Manufacturers Standardization Society of

14、 the Valve and Fittings Industry, Inc. Printed in U.S.A. MSS STANDARD PRACTICE SP-61 ii FOREWORD This Standard Practice for Pressure Testing of Valves was originally adopted in 1961. It was developed for the purpose of providing a uniform means of testing valves commonly used in the “full open“ and

15、“full closed“ type of service. For control valves, refer to standards ISA-75.19.01 and FCI 70-2, which may be more appropriate for control valve pressure testing. MSS STANDARD PRACTICE SP-61 iii TABLE OF CONTENTS SECTION PAGE 1 SCOPE . 1 2 DEFINITIONS 1 3 GENERAL REQUIREMENTS . 1 4 SHELL LEAKAGE TES

16、TS 2 5 SEAT CLOSURE TESTS . 2 TABLE 1 Shell Leakage Test Duration 2 2 Alternate Gas Test . 2 3 Seat Closure Test Duration 4 4 Units of Leakage per NPS/DN . 4 ANNEX A Referenced Standards and Applicable Dates . 5 MSS STANDARD PRACTICE SP-61 1 PRESSURE TESTING OF VALVES 1. SCOPE This Standard Practice

17、 establishes requirements and acceptance criteria for shell and seat closure pressure testing of valves. 2. DEFINITIONS 2.1 Production Pressure Test Pressure tests, which include closure member and shell leakage tests, shall be performed on production units manufactured for sale. Production pressure

18、 tests verify the pressure containing capability of production units. 2.2 Shell Leakage Test An internal pressure test of the pressure containing envelope to demonstrate pressure containing capability of the external pressure boundary. 2.3 Seat and Closure Member Test An internal pressure test of fl

19、ow regulating elements (seats, seals, and closure member such as gate, disc, ball, or plug) to demonstrate static pressure performance within allowable leakage tolerances. 2.4 No Visible Leakage 2.4.1 The term “no visible leakage“, applied to a hydrostatic test liquid, is defined as a leak rate that

20、 will produce no visible weeping or formation of drops (1) at the test pressure area and (2) for the duration of the test. 2.4.2 The term “no visible leakage“, as applied to air or gas testing, is defined as a leak rate(l)that will produce no visible formation of bubbles in a water immersion test or

21、 after application of leak detection fluid at the test pressure and for the duration of the test. 2.4.3 For automatic leak detection methods, this definition shall be considered equivalent to a leak rate no greater than 4.1 x 10-5in3/sec (6.7 x 10-4ml/sec)(l)with a pressure differential of 80 to 100

22、 psi (5.5 to 6.9 bar) for application to valves of NPS 8 (DN 200) and smaller. 3. GENERAL REQUIREMENTS 3.1 The manufacturer shall be responsible for the performance of tests specified herein. 3.2 Fluid for shell and seat closure tests shall be air, inert gas, or liquid, such as water (which may cont

23、ain a corrosion inhibitor), kerosene, or other fluid with viscosity not greater than that of water. Temperature of the test fluid shall not exceed 125 F (52 C). 3.3 Valves shall be substantially relieved of air or gas when tested with liquid. 3.4 Seat closure tests for NPS 4 (DN 100) and larger valv

24、es shall be conducted after an acceptable shell test. Seat closure tests for smaller valves may be conducted before or after the shell test at the manufacturers option. However, when valves conform to ASME B16.34, the requirements of Section 7.2 of ASME B16.34 shall apply. NOTE: (1) This leakage rat

25、e is based on the measured leakage of nitrogen gas from a needle valve with a 0.167 in. O.D. x 0.091 in. I.D. tube submerged in water to a depth of 1 inch. The tube end was cut square and smooth with no chamfers or butts and the tube axis was parallel to the surface of the water. Leakage was adjuste

26、d to a level equal to 40 bubbles in 10 minutes at 90 psi. The 40 bubbles equaled 1.6 ml or, 1 bubble = 0.04 SCC. Using this data, a leak rate equivalent to 1 bubble every minute is found to be 4.1 x 10-5in3/sec (6.7 x 10-4ml/sec). MSS STANDARD PRACTICE SP-61 2 3.5 Valves shall be shell tested prior

27、to painting. Corrosion protection treatment such as phosphatizing and linings may be applied prior to shell testing. If pressure tests in the presence of purchasers representative are specified, valves that were painted following successful pressure testing may be retested without removal of paint.

28、3.6 Valve test fixture loads applied to valve ends shall be limited to those required to effectively seal the valve ends. 3.7 Leakage detection devices, e.g., pressure decay devices, may be used for detecting leakage provided that they perform at the pressures specified in Sections 4 and 5. The valv

29、e manufacturer shall be able to demonstrate that, when these devices are used, the test results are equivalent to the requirements of this Standard Practice. 4. SHELL LEAKAGE TESTS 4.1 Each valve shall be given a shell leakage test at a gauge pressure no less than 1.5 times the valves 100 F (38 C) d

30、esign pressure rating, rounded off to the next higher 25 psi (1 bar) increment. 4.2 Shell leakage tests shall be conducted with the valve in the partially open position and with the valve ends closed. Pressure retaining parts of valves may be tested separately when the valves have internal component

31、s, such as diaphragms in diaphragm valves, which are not designed to withstand required shell test pressures. The manufacturers nameplate data shall contain reference to this limitation. 4.3 Visual leakage through the pressure boundary walls is not acceptable. Stem seal leakage during shell test sha

32、ll not be cause for rejection. Stem seals shall be capable of retaining pressure at least equal to the valves 100 F (38 C) design pressure rating without visible leakage. 4.4 The minimum duration of the shell leakage test shall be per Table 1. TABLE 1 Shell Leakage Test Duration VALVE SIZE TEST TIME

33、 NPS DN Seconds 2 and Smaller 50 and Smaller 15 212 6 65 150 60 8 12 200 300 120 14 and Larger 350 and Larger 300 5. SEAT CLOSURE TESTS 5.1 Each valve designed for shutoff or isolation service, such as stop valves and check valves, shall be given a fluid seat closure tightness test. 5.1.1 The seat c

34、losure test shall be performed at a fluid (liquid or gas) pressure no less than 1.1 times the valves 100 F (38 C) design pressure rating rounded to the next higher 5 psi (0.5 bar). At the manufacturers option, a gas pressure of no less than 80 psi (5.6 bar) may be substituted for the valve sizes and

35、 pressure classes listed in Table 2. TABLE 2 Alternate Gas Test VALVE SIZE PRESSURE CLASS NPS (DN) Class 12 (300) and Smaller 300 and Lower 4 (100) and Smaller All 5.1.2 Seat closure testing shall be performed with seat surfaces free of materials that aid in sealing except as provided for in Section

36、s 5.1.3 and 5.1.4. 5.1.3 When necessary to prevent damage during valve actuation, a light oil of viscosity no greater than that of kerosene may be applied to seating surfaces. MSS STANDARD PRACTICE SP-61 3 5.1.4 When a valves primary seat design is based on the presence of a sealant material, e.g.,

37、lubricated plug valves, the sealant material may be in place. When it is intended that sealants act as secondary or back-up seat seals, the sealant material shall not be in place during the closure test. 5.1.5 When lubricants are used for assembly operations, it is not required that these be removed

38、 prior to testing if their presence has no influence on the test results. 5.2 For valves of the double seating type such as many gate, plug, and ball valves, the test pressure shall be applied successively to each end of the closed valve and leakage to the opposite end checked. 5.2.1 As alternate me

39、thods for valves with independent double seating (such as double disc or split wedge gate valves), at the option of the manufacturer, the pressure may be applied inside the bonnet (or body) of the closed valve and each seat checked for leakage at the valve ports, or the pressure may be applied to th

40、e valve ports and the sum of seat leakage checked at the bonnet (or body). These alternate methods may be used at the option of the manufacturer for valves with single discs (such as solid or flexible wedge gate valves) provided a supplementary closure member test across the disc is performed. 5.3 F

41、or other valve types, the test pressure shall be applied across the closure member in the direction producing the most adverse seating condition. For example, a globe valve shall be tested with pressure under the disc. A check valve or other valve type that is designed, sold, and marked as a one-way

42、 valve, requires a closure test only in the appropriate direction. A stop check valve requires both tests. 5.4 Valves conforming to this Standard Practice in all respects, except those that are designed for operating conditions that have pressure differential across the closure member limited to pre

43、ssures less than the 100 F (38 C) pressure rating and having closure members and/or actuating devices (direct, mechanical, fluid, or electrical) that would be subject to damage at higher differential pressures, shall be tested as described above except that the closure test requirement may be reduce

44、d to 1.1 times the maximum specified closed position differential pressure. This exception may be exercised upon agreement between the purchaser and manufacturer. The manufacturers name plate data shall include reference to any such limitations. 5.5 Valves of single or symmetrical seat design that a

45、re capable of seating in two directions, e.g., butterfly or weir type diaphragm valves, require seat testing in only one direction. 5.6 Butterfly valves of the offset stem-seat design may be closure tested in only one direction. The manufacturer shall be able to demonstrate that the direction select

46、ed is that least likely to attain effective tightness. 5.7 Allowable leakage rates, except for the conditions of Sections 5.7.2 and 5.7.3, shall be as indicated in Section 5.7.1. 5.7.1 The maximum allowable leakage of each seat closure shall be 10 ml/hr of liquid or 0.1 standard cubic ft/hr of gas p

47、er unit of NPS (0.4 ml/hr of liquid or 120 standard ml/hr of gas per unit of DN) under the specified test condition. See Table 4. 5.7.2 In the case of valves having pressure or flow reversal actuated closure, e.g., check valves, the allowable leakage rate may be increased by a factor of four (4). MS

48、S STANDARD PRACTICE SP-61 4 5.7.3 In the case of valves having a seat closure member that uses a compliant material, e.g., plastic or elastomer, for fluid sealing at closure, there shall be no visible leakage for the duration of the seat test. 5.8 The duration of each seat closure test shall be per

49、Table 3. TABLE 3 Seat Closure Test Duration VALVE SIZE TEST TIME NPS DN Seconds 2 and Smaller 50 and Smaller 15 212 8 65 200 30 10 18 250 450 60 20 and Larger 500 and Larger 120 TABLE 4 Units of Leakage per NPS/DN LIQUID GAS Per NPS Per DN Per NPS Per DN 10 cc/hr 0.4 cc/hr 0.1 SCFH 2.88 SCIM 120 cc/hr 0.167 cc/min. 6.6 x10-3cc/min. 47.2 cc/min. 2cc/min. 2.66(a)drops/min. 0.11(a)drops/min. 1180(b)bubble/min. 50(b) bubble/min. TABLE 4 NOTES: (a) For information only. Based on 16 drops per cc, which is the equivalent of a spherical shaped drop having an