FM Approvals 7151-7156-7157:2021 PDF

This standard is concerned with the details of construction, operation and testing of LP-Gas vaporizers, gas-air mixers, and vaporizer-mixers. LP-Gas vaporizers are intended to aid vaporization of LP-Gas by supplying heat to liquefied LP-Gas. Gas-air mixers are used to mix the LP-Gas vapor with sufficient air to supply a mixture of the necessary heating content for the application, often as a substitute for natural gas. Vaporizer-mixers combine both functions in a single, integrally connected assembly. In vaporizers, heat may be provided by direct application of flame to the portion of the vaporizer containing the LP-Gas, by electrically heating the LP-Gas-containing portion, or by heating a transfer medium which is then used to heat the LP-Gas- containing-portion. Mixers may entrain atmospheric air or be connected to a compressed air source. This standard may consider, as necessary, the suitability of portions of the equipment for Class I, Division 1 or 2 hazardous (classified) locations and does consider the suitability of electrical equipment for its intended environmental conditions. The requirements of this standard shall be used to measure and describe the performance of LP-Gas vaporizers, mixers, and vaporizer-mixers in response to exposure to controlled test conditions. The results of these controlled exposures shall not be used to described or appraise actual exposure conditions, since such conditions will vary widely.