Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number D31BR found under Adapter Straight Pipe To Tube by Fluid System Components Inc. The National Stock Number assigned to this part is 4730015178577, and the Federal Supply Class is 4730 Hose Pipe Tube Lubrication And Railing Fittings. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like D31BR.