4820-00-289-2128 (DD445S4824-46ALT2)
4820-00-289-2128 is equivalent to manufacture part number A6821A. 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.