1.1 This specification covers requirements and test methods for excess flow valves for use in thermoplastic natural gas piping systems. However, it is expected that excess flow valves manufactured to the requirements of this specification may also be used in other natural gas piping systems.
1.2 Excess flow valves covered by this specification are designed for insertion into components for natural gas systems such as pipe, tubing, or fittings in sizes from 1/2 CTS to 2 IPS.
1.3 The tests required by this specification are intended to determine the performance characteristics of an excess flow valve installed in a straight piece of pipe. An excess flow valve could possibly be installed in a straight piece of pipe, in a service tee outlet, as part of a mechanical coupling, or in other configurations. The performance characteristics of the excess flow valve may be significantly different for each installed configuration. Users should conduct their own tests to determine the installed performance characteristics or contact the EFV manufacturer for test data for the installed configuration. Additional guidance on selection and installation of excess flow valves is included in Appendix X1.
1.4 The tests required by this specification are not intended to be routine quality control tests.
1.5 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory requirements prior to use.