Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 8188-012-021 8IN found under Retainer Gasket Val by Velan Valve Corporation. The National Stock Number assigned to this part is 4820012367235, 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 8188-012-021 8IN.