Aquatherm’s polypropylene-random piping systems are joined using heat fusion, a safe and flameless technology that has proven successful worldwide for nearly 40 years. Heat fusion physically joins two separate pieces of plastic without burning or chemically altering. Heating the polypropylene with a simple electric iron and allowing it to cool under pressure, the two pieces become one forming a bond that is nearly indistinguishable from the rest of the pipe and fitting.