4820-00-980-4919 (38301-4210)
NSN 4820-00-980-4919 (NIIN 00-980-4919) is a safety relief valve in Federal Supply Class 4820, Valves, Nonpowered — a valve designed to automatically release excessive pressures. Manufacturer part number 38301-4210 (Fluid Mechanics Valve Company, CAGE 52253); also referenced as 2-906 (Trw IncTrw Mission Drillling).
Key specs: pressure tight outlet side; full characteristics table below. NIIN assigned January 1962; DEMIL A (none required); unit of issue EA (each), $353.78 gov standard price; export Schedule B 8481.40.0000.