... : a) SV-40: BSP11/2", NPT11/2", double, 1.6kg b) SV-50: BSP2", NPT2", double, 2.4kg c) SV-80: BSP3", NPT3 ... ", double, 5kg5) Installed on the bottom of suction tubes ... storage tank to maintain prime in suction system fuel lines6) Double-poppet models provide redundant protection for holding the prime, and ...