UL 51

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These requirements cover power-operated pumps for anhydrous ammonia and liquefied petroleum gas (LP-Gas) for use in liquid transfer operations in nonrefrigerated systems in installations covered by the:

1. Safety Requirements for the Storage and Handling of Anhydrous Ammonia, CGA G-2.1 (ANSI K61.1) and
2. Standard for Storage and Handling of Liquefied Petroleum Gases, NFPA No. 58 (National Fire Codes, volume 2).

These requirements do not cover:

1. Pumps or compressors intended for handling anhydrous ammonia or LP-Gas in the gaseous phase and
2. Pumps or compressors for anhydrous ammonia or LP-Gas for use in chemical, petro-chemical, petroleum, or utility power plants; nor pipeline or marine terminals; nor related storage facilities at such plants or terminals.