1、MSS SP-115-2017 Excess Flow Valves,NPS 11/4 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 22180-4602 Phone: (703) 281-6613 Fax: (703) 281-6671 E-mail
2、: standardsmsshq.org www.msshq.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 resulting efforts of competent and experienced volunteers
3、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 practice by the manufacturer, the user, and the general public. The existence of an MSS Standard Pract
4、ice 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 other documents such as a code, specification, sales contract, or public law, as applicable. MSS has
5、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 attributable to MSS and is solely the responsibility of the certifier or maker of the statement. “Unle
6、ss 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 of approval of this MSS Standard Practice (see Annex B). This Standard Practice shall remain silent o
7、n 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 with respect to the validity of any potential claim(s) or of any patent rights in connection therewith
8、. 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 responsibility. In this Standard Practice, all text, notes, annexes, tables, figures, and references a
9、re 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 document are construed as “supplemental”. Note that supplemental information does not include mandatory
10、requirements. Substantive changes in this 2017 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. Non-toleranced dimensions in this Standard Practic
11、e are nominal unless otherwise specified. Excerpts of this Standard Practice may be quoted with permission. Credit lines should read Extracted from MSS SP-115-2017 with permission of the publisher, Manufacturers Standardization Society of the Valve and Fittings Industry. Reproduction and/or electron
12、ic 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: July 1995 Originally Published: August 1995 Current Edition Ap
13、proved: June 2016 Current Edition Published: January 2017 Copyright , 2017 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
14、 TYPES AND SIZES 2 4 SERVICE PRESSURETEMPERATURE RATINGS . 2 5 MATERIALS . 2 6 DESIGN . 2 7 MARKING . 3 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 App
15、licable Dates 8 MSS STANDARD PRACTICE SP-1151 EXCESS FLOW VALVES, 1 NPS AND SMALLER, FOR FUEL GAS SERVICE 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
16、 predetermined level. 1. SCOPE 1.1 This Standard Practice covers Excess Flow Valves, NPS 11/4and smaller, used in fuel gas distribution systems with operating pressures of 5 inches water column (in. WC) and above. 2. DEFINITIONS AND ABBREVIATIONS 2.1 Requirements for Excess Flow Valves covered by th
17、is Standard Practice are classified into two pressure ranges as follows: a) Low Pressure Valves for use on systems with pressures between 5 in. WC 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
18、 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 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 serv
19、ice line downstream is made gas tight and pressure is equalized across the valve. 2.2.2 Excess Flow Valve Non-Bypass (EFVNB) 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 predetermi
20、ned level of gas flow through an EFV at a given inlet pressure which causes closure. 2.4 Bleed-by Flow Rate The amount of 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 D
21、esign Inlet Pressure The minimum pressure at which the EFV is designed to function as specified by the manufacturer. 2.7 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 thi
22、s Standard Practice are as follows: F degrees Fahrenheit NPS Nominal Pipe Size CTS Copper Tube Size psia pounds per square inch absolute pressure EFV Excess Flow Valve psig pounds per square inch gage pressure EFVB Excess Flow Valve Bypass SCFH Standard Cubic Feet per Hour EFVNB Excess Flow Valve No
23、n-Bypass SG Specific Gravity in. WC inches water column pressure (also expressed as: ”w.c.) MSS STANDARD PRACTICE SP-1152 3. VALVE TYPES AND SIZES 3.1 Valve Types 3.1.1 Excess Flow Valve Bypass (EFVB) See Section 2.2.1. 3.1.2 Excess Flow Valve Non-Bypass (EFVNB) See Section 2.2.2. 3.2 Nominal Pipe S
24、izes The EFVs covered by this Standard Practice shall be constructed to fit piping systems no smaller than 1/2 in. CTS and no larger than NPS 11/4, including both pipe and tubing sizes. 4. SERVICE PRESSURE-TEMPERATURE RATINGS 4.1 EFVs covered by this Standard Practice will normally have the followin
25、g characteristics, except when agreed otherwise by purchaser and manufacturer: a) A minimum design inlet pressure of 5 in. WC or greater b) A maximum operating pressure of 125 psig or less c) A minimum temperature rating of -20 F d) A maximum temperature rating of 140 F 5. MATERIALS 5.1 General Mate
26、rials used in the manufacture of an EFV shall be those compatible 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
27、/A53M, ASTM A106/A106M, ASTM A333/A33M, ASTM A513/A513M, and ASTM D2513. 6. DESIGN 6.1 General All data reported from tests performed with this Standard Practice shall be based on standard conditions of 60 F and 14.7 psia. All flow rates (closure, bleed-by, leak rate, etc.) referred to in this Stand
28、ard Practice are stated in SCFH 0.6 SG Gas unless stated otherwise. Corrections shall be made to data measured at conditions other than those stated above. 6.1.1 U.S. Federal Standards EFVs shall comply with U.S. Code of Federal Regulations (DoT) 49 CFR 192.381 where applicable. 6.2 EFV Closure Flow
29、 Rate All EFVs shall have a closure flow rate no less than the EFV manufacturers rated published closure flow rate and no greater than 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 Pressu
30、re (5 in. WC to 5 psig) The bleed-by flow rate after valve closure shall not exceed the following: a) 5 SCFH at an inlet pressure of 5 in. WC 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 i
31、nlet pressure of 10 psig. MSS STANDARD PRACTICE SP-1153 6.3.2 Excess Flow Valve Non-Bypass (EFVNB) The maximum permissible leak rate after valve closure shall not exceed 0.40 SCFH, per inch of diameter of nominal valve size, for all rated operating inlet pressures. 7. MARKING 7.1 General Each EFV sh
32、all be marked on their outer most surfaces for installation in accordance with MSS SP-25 with at least the following: a) Manufacturers identification b) Type of EFV: Bypass (EFVB) or Non-Bypass (EFVNB) c) Flow direction arrow d) Nominal Pipe Size e) Pressure rating designation f) Lot identification
33、7.2 Additional Markings 7.2.1 Low Pressure (5 in. WC to 5 psig) Additional markings may be applied in accordance with MSS SP-25 and ANSI Z21.93/CSA 6.30 (previously known as IAS 3-92). 7.2.2 High Pressure (5 psig and above) Additional markings may be applied in accordance with MSS SP-25. 7.3 Meter L
34、ocation 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 installed. 8. DESIGN QUALIFICATION TESTING 8.1 General This section is intended to provide technical information to the user of EFVs on the performance cha
35、racteristics of a manufacturers valve. The technical information produced from this testing will assist the user in determining the proper application of an EFV. This section is intended to provide specific EFV performance requirements and to outline the testing that shall be performed by the user,
36、manufacturer, or other party to evaluate EFVs. The test apparatus, equipment, and procedure used in performing the outlined tests shall be such that data obtained from the tests can be confirmed. The following standards shall be referenced and used when testing to this Standard Practice: a) Low Pres
37、sure (5 in. WC to 5 psig) ANSI Z21.93/CSA 6.30 (previously known as IAS 3-92) b) High Pressure (5 psig and above) ASTM F1802, ASTM F2138 The following tests within Section 8 shall be made by the manufacturer on a sample lot of EFVs. The sample size shall be no less than 25 valves unless agreed other
38、wise by purchaser and manufacturer. Each rated minimum closure flow rate model shall be “design qualified” under this section. Testing shall be performed at 67 10 F. Alternate optional test temperatures are -20 10 F and 140 10 F. GENERAL NOTE: Orientation of the valve for testing is in the horizonta
39、l 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. MSS STANDARD PRACTICE SP-1154 8.2 Closure Flow Tes
40、t 8.2.1 Low Pressure (5 in. WC 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 manufacturers specifications and the limits specified in Section 6.2. 8.2.2
41、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 within manufacturers specifications and the limits specified in Section 6.2. 8.3 B
42、leed-by Flow Rate/Leak Rate after Closure Test 8.3.1 Excess Flow Valve Bypass (EFVB) 8.3.1.1 Low Pressure (5 in. WC to 5 psig) EFVBs shall be tested at the minimum and maximum inlet pressure. Additional tests at other inlet pressures may be performed. The bleed-by flow rate of the valve shall be wit
43、hin the limits specified in Section 6.3.1.1. The bleed-by flow rate of the valve at inlet pressures other than 5 in. WC shall be within manufacturers specifications. 8.3.1.2 High Pressure (5 psig and above) EFVBs shall be tested at the minimum design inlet pressure, 10 psig, and 60 psig. Additional
44、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 other than 10 psig shall be within manufacturers specifications. 8.3.2 Excess Flow Valve Non-Bypass (EF
45、VNB) 8.3.2.1 Low Pressure (5 in. WC 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 shall be within the limits specified in Section 6.3.2. 8.3.2.2 High Pressure (5 psig and above) EFVN
46、Bs 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 specified in Section 6.3.2. 8.4 Pressure Drop Across EFV Tests 8.4.1 Pressure Drop at Flow Rates less than
47、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, 1000, 1250, and 1500 SCFH. Additional tests at inlet pressures and flow rates other than those listed
48、 above may be performed. The pressure drop values shall be within manufacturers specifications. 8.4.1.1 Low Pressure (5 in. WC to 5 psig) EFVs shall be tested per Section 8.4.1 at the minimum and maximum inlet pressure. 8.4.1.2 High Pressure (5 psig and above) EFVs shall be tested per Section 8.4.1
49、at the minimum design inlet pressure, 10 psig, and 60 psig. 8.4.2 Pressure Drop just Prior to Closure The maximum obtainable pressure 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 in. WC 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.
