Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number UD 4045 VB found under Stem Fluid Valve by Nash Engineering Company Inc The. The National Stock Number assigned to this part is 4820011846616, 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 UD 4045 VB.