This specification provides the minimum requirements for design, construction, performance, and testing of two types of tank vent flame arrester (Type I and Type II). This specification is intended for flame arresters protecting systems containing vapors of flammable or combustible liquids with the specified vapor temperature. The defined test media can be used except where arresters protect systems handling vapors with the given value of maximum experimental safe gap (MESG). Flame arresters protecting such systems must be tested with appropriate media. The flame arrester housing, and other parts or bolting used for pressure retention, shall be constructed of the prescribed materials. Arrester, elements, gaskets, and seals shall be of materials resistant to attack by seawater and the liquids and vapors contained in the tank being protected. Nonmetallic materials, other than gaskets and seals, shall not be used in the construction of pressure-retaining components and nonmetallic gaskets and seals shall be noncombustible and suitable for the service intended. The possibility of galvanic corrosion shall be considered in the selection of materials. Requirements for flame arrester design and construction, housings, elements, threaded or flanged pipe connections, joints, and fastenings are detailed. Prototype testing such as corrosion test, performance test, endurance burn test, and flashback test shall be done.

1.1 This specification provides the minimum requirements for design, construction, performance, and testing of tank vent flame arresters.

1.2 This specification is intended for flame arresters protecting systems containing vapors of flammable or combustible liquids where vapor temperatures do not exceed 60°C. The test media defined in 9.1.1 can be used except where arresters protect systems handling vapors with a maximum experimental safe gap (MESG) below 0.9 mm. Flame arresters protecting such systems must be tested with appropriate media (the same vapor or a media having a MESG no greater than the vapor). Various gases and their respective MESG are listed in Table 1.

1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.

1.4 The following precautionary caveat pertains only to the test methods portions, Sections 8 and 9, of this specification: 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.5 This standard should be used to measure and describe the properties of materials, products, or assemblies in response to heat and flame under controlled laboratory conditions and should not be used to describe or appraise the fire hazard or fire risk of materials, products, or assemblies under actual fire conditions. However, results of this test may be used as elements of a fire risk assessment which takes into account all of the factors which are pertinent to an assessment of the fire hazard of a particular end use

1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.