National Diversified Sales U-1500-T 1-1/2" FPT x FPT Threaded PVC SCH 80 Union - This SCH 80 union joins two lengths of pipe and allows for future disconnecting of the pipes if needed. SCH 80 PVC pipe is a polyethylene, thicker pipe. It is predominantly used in commercial or industrial applications. These applications are more demanding and need piping that will last in high pressures and harsh environments.