The Polychek check valve from Advanced Pedestals has a fully opening flapper that allows the entire piping system to be pigged without being dismantled. Once installed, it eliminates the possibility of corrosion and leakage, as the exterior is constructed of 3608/4710 HDPE and fusion welded into place. This also eliminates the need for transitions, unions and other metal fittings, which can corrode, leak, and add extra cost and time to the installation. The inner workings are constructed of plastic resins that aren’t susceptible to corrosion or distortion by temperature or chemicals. The flapper hinges are made of 316 stainless steel rod. It has NSF 61G approval. 940/668-4371; www.polychek.com.