Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 521084-1 found under Cap Valve by York Precision Machining And Hydraulics Llc. The National Stock Number assigned to this part is 1650013001614, and the Federal Supply Class is 1650 Aircraft Hydraulic Vacuum And De-Icing System Components. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 521084-1.