Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 1 4"__ 44 77 PT SLK found under Valve Bleeder Hydraulic System by Flowserve Corporation. The National Stock Number assigned to this part is 4820011586193, 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 1 4"__ 44 77 PT SLK.