4820-01-379-0370 (FF-1-B)
NSN 4820-01-379-0370 (NIIN 01-379-0370) is a vacuum breaking valve in Federal Supply Class 4820, Valves, Nonpowered — an item designed to automatically relieve vacuum, by the intake of air, when the internal pressure falls below atmospheric pressure. Manufacturer part number FF-1-B (Haywardindl. Products, Inc., CAGE 73124).
NIIN assigned August 1993; DEMIL A (none required); ESD/EMI-sensitive; export Schedule B 8481.80.9050.