Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number RK8AT found under Parts Kit Stop Diaphragm Valve by Watts Regulator Co. The National Stock Number assigned to this part is 4820014232018, 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 RK8AT.