Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 939-100 found under Tube Flue Boiler by Aqua Chem Inc. The National Stock Number assigned to this part is 4710007754019, and the Federal Supply Class is 4710 Pipe Tube And Rigid Tubing. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 939-100.