GENTEC® Check Valves prevent reverse flow of gases which can cause dangerous mixtures. Choose from four styles to fit your needs: 24-CV5 series check valves are attached to the torch ends with “A” size fittings; 24-CV7 series check valves are attached to the torch ends with “B” size fittings; 24-CV8 series check valves replace the standard “B” size outlet bushings on regulators; 24-CV9 series check valves attach to the “B” size outlet bushings on the regulators.