4820-00-639-9621 (NMP-204-1/4-101T140P)
4820-00-639-9621 is equivalent to manufacture part number L-2120-C. It is a safety relief valve and is classified under Federal Supply Class 4820 (4820 - Valves, Nonpowered), stocked for defense, aerospace, MRO, and industrial maintenance applications. This item is cataloged in the NATO supply system under 4820 - Valves, Nonpowered and is available through NSN-PARTS for U.S. government MRO, and commercial procurement.