Blueline FRPP Reducing Double Sanitary Tees are used in chemical waste drainage applications such as laboratories in schools, universities, and research facilities. They're molded from proxylene blueline resin, a flame retardant thermoplastic material with excellent resistance to most common and organic mineral acids and their salts, strong and weak alkalis, and most organic chemicals. There are two methods for joining fittings and pipe. The No-Hub mechanical joint is an economical, fast, and easy method that requires only standard hand tools. No-Hub uses a stainless steel outer coupling to create tight, leak-free, and reconfigurable joints. The Rionfuse CF electrofusion joining system makes it easy to create strong joints that resist aggressive acids and chemicals. A heavy gauge wire is molded into the Rionfuse coupling, and permanent hermetically-sealed joints can be made quickly with the Rionfuser electrofusion machine.