4820-01-018-1720 (MIL-V-18436)
4820-01-018-1720 is equivalent to manufacture part number 41. It is a check 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.