4820-00-822-4644 (MIL-DTL-18436)
4820-00-822-4644 is equivalent to manufacture part number 4201-4. 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.