Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number R63870B11E8369 found under Valve Safety Relief by Unifab Industries Inc. The National Stock Number assigned to this part is 4820000738405, 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 R63870B11E8369.