Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number VTS 250 D-540 0781-3506 found under Regulator Compresse by Victor Equipment Co. The National Stock Number assigned to this part is 4820013142130, 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 VTS 250 D-540 0781-3506.