Precision molded Plastic Diaphragm Check Valves. All parting lines on the critical sealing surfaces have been eliminated. After molding, check valves are assembled using a non-toxic technique without the use of foreign materials. Body materials include Nylon, Polycarbonate, Kynar and Polypropylene. Available with Silicone, Viton® and Neoprene seals. Cracking Pressure = 6" of H2O Max Pressure: 50 psi