Praher Plastics 460-30-E 3" Wafer Check Valve PVC/EPDM for use to control fluid flow direction and reduce back flow within plumbing systems. Constructed of durable and corrosion proof materials, Praher Plastics is a leading producer of Thermoplastic Valves and Fittings. Easy to install and designed for durability, trust Praher for your pool or spa replacement parts.