1、 MSS SP-115-2010 Excess Flow Valves, 11/4NPS and Smaller, for Fuel Gas Service Standard Practice Developed and Approved by the Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. 127 Park Street, NE Vienna, Virginia 22180 Phone: (703) 281-6613 Fax: (703) 281-6671 e-mail: i
2、nfomss-hq.org www.mss-hq.org MSS STANDARD PRACTICE SP-115i This MSS Standard Practice was developed under the consensus of the MSS Technical Committee 501 and the MSS Coordinating Committee. The content of this Standard Practice is the result of the efforts of competent and concerned volunteers to p
3、rovide an effective, clear, and non-exclusive specification that will benefit the industry as a whole. This MSS Standard Practice 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 preclude th
4、e manufacture, sale, or use of products not conforming to the Standard Practice. Mandatory conformance is established only by reference in a code, specification, sales contract, or public law, as applicable. “Other standards documents referred to herein are identified by the date of issue that was a
5、pplicable to this Standard Practice at the date of issue of this Standard Practice. See Annex B. This Standard Practice shall remain silent on the applicability of those other standards of prior or subsequent dates of issue even though applicable provisions may not have changed. References contained
6、 herein which are bibliographic in nature are noted as supplemental in the text.” Unless otherwise specifically noted in this MSS Standard Practice, any standard referred to herein is identified by the date of issue that was applicable to the referenced standard(s) at the date of issue of this MSS S
7、tandard Practice (See Annex B). In this Standard Practice all notes, annexes, tables, and figures are construed to be essential to the understanding of the message of the standard, and are considered part of the text unless noted as “supplemental“. All appendices, if included, that appear in this do
8、cument are construed as “supplemental“. Supplemental information does not include mandatory requirements for this Standard Practice. Substantive changes in this 2010 edition are “flagged” by parallel bars as shown on the margins of this paragraph. The specific detail of the change may be determined
9、by comparing the material flagged with that in the previous edition. Any part of this Standard Practice may be quoted. Credit lines should read Extracted from MSS SP-115-2010 with permission of the publisher, Manufacturers Standardization Society of the Valves and Fittings Industry, Inc. Reproductio
10、n is prohibited under copyright convention unless written permission is granted by Manufacturers Standardization Society of the Valve and Fittings Industry Inc. Originally Approved: July 1995 Originally Published: August 1995 Current Edition Approved: May 2010 Current Edition Published: September 20
11、10 Copyright , 1995, 1999, 2006, 2010 by Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. Printed in U.S.A. MSS STANDARD PRACTICE SP-115ii TABLE OF CONTENTS SECTION PAGE PURPOSE . 1 1 SCOPE 1 2 DEFINITIONS AND ABBREVIATIONS . 1 3 VALVE TYPES AND SIZES 1 4 SERVICE PRESSU
12、RE TEMPERATURE RATINGS . 2 5 MATERIALS . 2 6 DESIGN . 2 7 MARKING . 2 8 DESIGN QUALIFICATION TESTING 3 9 PRODUCTION TESTING BY MANUFACTURER 5 FIGURE A1 Snap-Acting Loads Test Setup . 7 ANNEX A Snap-Acting Loads Test Setup Procedure 7 B Referenced Standards and Applicable Dates 8 MSS STANDARD PRACTIC
13、E SP-1151 PURPOSE To provide a Standard Practice for Excess Flow Valves that are designed and installed in fuel gas piping systems to reduce the flow of gas should the flow in the service line exceed some predetermined level. 1. SCOPE 1.1 This Standard Practice covers Excess Flow Valves used in fuel
14、 gas distribution systems with operating pressures of 5 inches water column (”w.c.) and above. 2. DEFINITIONS AND ABBREVIATIONS 2.1 Requirements for Excess Flow Valves covered by this Standard Practice are classified into two pressure ranges as follows: a) Low Pressure Valves for use on systems with
15、 pressures between 5”w.c. and 5 psig. b) High Pressure Valves for use on systems with pressures of 5 psig and above. 2.2 Excess Flow Valve (EFV) A device designed to automatically stop or limit the flow of gas in the event that the flow in the fuel gas service line in which it is installed exceeds a
16、 predetermined level. 2.2.1 Excess Flow Valve Bypass (EFVB) An EFV designed to limit the flow of gas upon closure to a predetermined level. EFVBs reset automatically once the service line downstream is made gas tight and pressure is equalized across the valve. 2.2.2 Excess Flow Valve Non-Bypass (EFV
17、NB) An EFV designed to stop the flow of gas upon closure and prevent equalization of pressure across the valve. EFVNBs must be manually reset. 2.3 Closure Flow Rate The predetermined level of gas flow through an EFV at a given inlet pressure which causes closure. 2.4 Bleed-by Flow Rate The amount of
18、 gas flow at a given inlet pressure through an EFVB after closure. 2.5 Leak Rate The amount of gas flow at a given inlet pressure through an EFVNB after closure. 2.6 EFV Minimum Design Inlet Pressure The minimum pressure at which the EFV is designed to function as specified by the manufacturer. 2.7
19、EFV Maximum Operating Pressure The maximum pressure at which the EFV is designed to function as specified by the manufacturer. 2.8 Abbreviations Abbreviations of terms used in this Standard Practice are as follows: a) EFV Excess Flow Valve b) EFVB Excess Flow Valve Bypass c) EFVNB Excess Flow Valve
20、Non-Bypass d) SCFH Standard Cubic Feet per Hour e) psig pounds per square inch gage pressure f) psia pounds per square inch absolute pressure g) ”w.c. inches water column pressure h) SG Specific Gravity i) CTS Copper Tube Size j) NPS Nominal Pipe Size k) F degrees Fahrenheit 3. VALVE TYPES AND SIZES
21、 3.1 Valve Types 3.1.1 Excess Flow Valve Bypass (EFVB) See Section 2.2.1. EXCESS FLOW VALVES, 11/4NPS AND SMALLER, FOR FUEL GAS SERVICE MSS STANDARD PRACTICE SP-1152 3.1.2 Excess Flow Valve Non-Bypass (EFVNB) See Section 2.2.2. 3.2 Nominal Pipe Sizes The EFVs covered by this Standard Practice shall
22、be constructed to fit piping systems no smaller than 1/2CTS and no larger than 11/4NPS, including both pipe and tubing sizes. 4. SERVICE PRESSURE-TEMPERATURE RATINGS 4.1 EFVs covered by this Standard Practice will normally have the following characteristics, except when agreed otherwise by purchaser
23、 and manufacturer: a) A minimum design inlet pressure of 5”w.c. or greater b) A maximum operating pressure of 125 psig or less c) A minimum temperature rating of -20F d) A maximum temperature rating of 140F 5. MATERIALS 5.1 General Materials used in the manufacture of an EFV shall be those compatibl
24、e with the applicable fuel gas and suitable for the intended purpose. 5.2 Pipe and Tubing Standards Reference Annex B for a partial listing of applicable pipe and tubing standards for use with the manufacture of EFVs; including ASTM A53, ASTM A106, ASTM A333, ASTM A513, and ASTM D2513. 6. DESIGN 6.1
25、 General All data reported from tests performed with this Standard Practice shall be based on standard conditions of 60F and 14.7 psia. All flow rates (closure, bleed-by, leak rate, etc.) referred to in this Standard Practice are stated in SCFH 0.6 SG Gas unless stated otherwise. Corrections shall b
26、e made to data measured at conditions other than those stated above. 6.1.1 Federal Standards EFVs shall comply with 49 CFR 192.381 where applicable. 6.2 EFV Closure Flow Rate All EFVs shall have a closure flow rate no less than the EFV manufacturers rated published closure flow rate and no greater t
27、han 50% above the rated published closure flow rate at any given operating pressure. 6.3 Bleed-by Flow/Leak Rate 6.3.1 Excess Flow Valve Bypass (EFVB) 6.3.1.1 Low Pressure (5”w.c. to 5 psig) The bleed-by flow rate after valve closure shall not exceed the following: a) 5 SCFH at an inlet pressure of
28、5”w.c. b) 18 SCFH at an inlet pressure of 5 psig 6.3.1.2 High Pressure (5 psig and above) The bleed-by flow rate after valve closure shall not exceed 20 SCFH at an inlet pressure of 10 psig. 6.3.2 Excess Flow Valve Non-Bypass (EFVNB) The maximum permissible leak rate after valve closure shall not ex
29、ceed 0.40 SCFH, per inch of diameter of nominal valve size, for all rated operating inlet pressures. 7. MARKING 7.1 General Each EFV shall be marked on their outer most surfaces for installation in accordance with SP-25 with at least the following: a) Manufacturers identification b) Type of EFV: Byp
30、ass (EFVB) or Non-Bypass (EFVNB) c) Flow direction arrow d) Nominal Pipe Size e) Pressure rating designation f) Lot identification MSS STANDARD PRACTICE SP-1153 7.2 Additional Markings 7.2.1 Low Pressure (5”w.c. to 5 psig) Additional markings may be applied in accordance with SP-25 and IAS 3-92 Requ
31、irements for Excess Flow Valves. 7.2.2 High Pressure (5 psig and above) Additional markings may be applied in accordance with MSS SP-25. 7.3 Meter Location It is recommended that the manufacturer supply an EFV tag or label which can be affixed at the meter location to identify that an EFV is install
32、ed. 8. DESIGN QUALIFICATION TESTING 8.1 General This section is intended to provide technical information to the user of EFVs on the performance characteristics of a manufacturers valve. The technical information produced from this testing will assist the user in determining the proper application o
33、f an EFV. This section is intended to provide specific EFV performance requirements and to outline the testing that shall be performed by the user, manufacturer, or other party to evaluate EFVs. The test apparatus, equipment, and procedure used in performing the outlined tests shall be such that dat
34、a obtained from the tests can be confirmed. The following standards shall be referenced and used when testing to this Standard Practice: a) Low Pressure (5”w.c. to 5 psig) IAS 3-92 Requirements for Excess Flow Valves b) High Pressure (5 psig and above) ASTM F1802, ASTM F2138 Note: Orientation of the
35、 valve for testing is in the horizontal position unless otherwise specified by the manufacturer. Test apparatus and procedures referenced in the above mentioned standards may need to be modified to accommodate manufacturers required valve orientation in positions other than horizontal. The following
36、 tests shall be made by the manufacturer on a sample lot of EFVs. The sample size shall be no less than 25 valves unless agreed otherwise by purchaser and manufacturer. Each rated minimum closure flow rate model shall be design qualified under this section. Testing shall be performed at 67 10F. Alte
37、rnate optional test temperatures are -20 10F, and 140 10F. 8.2 Closure Flow Test 8.2.1 Low Pressure (5”w.c. to 5 psig) EFVs shall be tested at the minimum and maximum design inlet pressure. Additional tests at other inlet pressures may be performed. The closure flow rate of the valve shall be within
38、 manufacturers specifications and the limits specified in Section 6.2. 8.2.2 High Pressure (5 psig and above) EFVs shall be tested at the minimum design inlet pressure, 10 psig, and 60 psig. Additional tests at other inlet pressures may be performed. The closure flow rate of the valve shall be withi
39、n manufacturers specifications and the limits specified in Section 6.2. 8.3 Bleed-by Flow Rate/Leak Rate after Closure Test 8.3.1 Excess Flow Valve Bypass (EFVB) 8.3.1.1 Low Pressure (5”w.c. to 5 psig) EFVBs shall be tested at the minimum and maximum inlet pressure. Additional tests at other inlet p
40、ressures may be performed. The bleed-by flow rate of the valve shall be within the limits specified in Section 6.3.1.1. The bleed-by flow rate of the valve at inlet pressures other than 5”w.c. shall be within manufacturers specifications. MSS STANDARD PRACTICE SP-1154 8.3.1.2 High Pressure (5 psig a
41、nd above) EFVBs shall be tested at the minimum design inlet pressure, 10 psig, and 60 psig. Additional tests at other inlet pressures may be performed. The bleed-by flow rate of the valve shall be within the limits specified in Section 6.3.1.2. The bleed-by flow rate of the valve at inlet pressures
42、other than 10 psig shall be within manufacturers specifications. 8.3.2 Excess Flow Valve Non-Bypass (EFVNB) 8.3.2.1 Low Pressure (5”w.c. to 5 psig) EFVNBs shall be tested at the minimum and maximum inlet pressure. Additional tests at other inlet pressures may be performed. The leak rate of the valve
43、 shall be within the limits specified in Section 6.3.2. 8.3.2.2 High Pressure (5 psig and above) EFVNBs shall be tested at the minimum design inlet pressure, 10 psig, and 60 psig. Additional tests at other inlet pressures may be performed. The leak rate of the valve shall be within the limits specif
44、ied in Section 6.3.2. 8.4 Pressure Drop Across EFV Tests 8.4.1 Pressure Drop at Flow Rates less than Closure Pressure drop measurements shall be taken at the following flow rates which are less than the valves minimum closure flow rate at the given inlet test pressure: 100, 200, 300, 400, 500, 750,
45、1000, 1250 and 1500 SCFH Additional tests at inlet pressures and flow rates other than those listed above may be performed. The pressure drop values shall be within manufacturers specifications. 8.4.1.1 Low Pressure (5”w.c. to 5 psig) EFVs shall be tested per Section 8.4.1 at the minimum and maximum
46、 inlet pressure. 8.4.1.2 High Pressure (5 psig and above) EFVs shall be tested per Section 8.4.1 at the minimum design inlet pressure, 10 psig, and 60 psig. Examples: a) If a valves minimum design inlet pressure is 10 psig and its minimum closure flow rate at 10 psig is 400 SCFH, then pressure drop
47、measurements at this inlet pressure shall be taken at 100, 200, and 300 SCFH. b) If a valves minimum design inlet pressure is 5 psig and its minimum closure flow rate at 5 psig is 1800 SCFH, then pressure drop measurements at this inlet pressure shall be taken at 100, 200, 300, 400, 500, 600, 750, 1
48、000, 1250, and 1500 SCFH. c) If a valves minimum design inlet pressure is 5”w.c. and its minimum closure flow rate at 5”w.c. is 290 SCFH, then pressure drop measurements at this inlet pressure shall be taken at 100 and 200 SCFH. 8.4.2 Pressure Drop just Prior to Closure The maximum obtainable pressu
49、re drop across the valve prior to closure shall be measured. This reading may be taken at a flow rate equal to a minimum of 99% of the closure flow rate. The pressure drop values shall be within manufacturers specifications. 8.4.2.1 Low Pressure (5”w.c. to 5 psig) EFVs shall be tested per Section 8.4.2 at the minimum and maximum inlet pressure. Additional tests at other inlet pressures may be performed. 8.4.2.2 High Pressure (5 psig and above) EFVs shall be tested per Section 8.4.2 at the minimum design inlet pre
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