Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 1-33-13283 found under Valve Check by Marley Pump Co. The National Stock Number assigned to this part is 4820011238566, 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 1-33-13283.