Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number DDG 8873 3IN S151F-6-316 found under Valve Check by William E Williams Valve Corp. The National Stock Number assigned to this part is 4820013304938, and the Federal Supply Class is 4820 Valves Nonpowered. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like DDG 8873 3IN S151F-6-316.