Valterra 200-C10 PVC Swing/Spring Combination Check Valve, Clear, fits 1" PVC pipe Schedule 40 PVC construction for strength and resistance to corrosion and mild chemicals EPDM seal for resistance to water and oils Maximum pressure rating of 150 psi Spring tension of 1/2 lb. for secure closure of valve This item is made to fit over a 1" PVC pipe. It is a slip fitting.