4 inch Brass Anti Reverse Valve for Vacuum pump NPT with ABS inserts

Description Mounts before vacuum pump on intake to keep vacuum pump from going backwards at shutdown. Fits 4 inch pipe NPT or comes with ABS Inserts to use with Fernco Rubber couplings (recommended to reduce vibration) Brass body Nylon insert Rubber seal One way valve. must be installed vertically in correct orientation Works with Sutorbilt, Gardner Denver, Kaizer, Kaiser, RBS vacuum systems ARV 400 - VCBL1-400 Made in Italy