UL 51

Abstract

These requirements cover power-operated pumps and bypass valves for use in liquid transfer operations in non-refrigerated systems in installations for: <br>a) Anhydrous ammonia systems installed in accordance with the Safety Requirements for the Storage and Handling of Anhydrous Ammonia, CGA/GAS G-2.1 (ANSI K61.1); <br>b) Liquefied petroleum gas (LP-Gas) systems installed in accordance with the Liquefied Petroleum Gas Code, NFPA No. 58; and <br>c) Propylene systems. <br>These requirements do not cover: <br>a) Pumps or compressors intended for handling anhydrous ammonia or LP-Gas or propylene in the gaseous phase and <br>b) Pumps, compressors or bypass valves for anhydrous ammonia, LP-Gas, or propylene 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. <br>Equipment covered by these requirements is for use with LP-Gas, propylene, or anhydrous ammonia as covered by the Standards and Codes and shall have a minimum service pressure rating. <br><em>Exception: A pump without an integral bypass valve with a higher differential pressure obtained in the Differential Pressure Test, Section 17, is permitted to have a lower minimum service pressure rating if it is marked in accordance with 25.2.</em>