Induction heating apparatus for controlling the welding parameter of temperature for heat treating a section of piping

A heating induction apparatus for controlling the welding parameter of temperature for a section of metal piping, which heating apparatus is comprised of:

• a pair of opposed heating collars spaced substantially parallel and contiguous with a weld joint, each heating collar comprising a resistance wire network which is capable of creating a thermal resistance through the network when voltage is applied across the wire, an inner core which is contiguous with the piping and absorbs the thermal heat energy from the network and transfers it to the piping, each heating collar further comprising a protective layer, said protective layer providing a protective outer covering for supporting and protecting said heating collar from the external environment, said protective layer further comprising fastening means for securing each collar securely around the piping;
• and
• a thermostatic control mechanism comprising a means for controlling the voltage applied across the network;
• wherein the thermostatic control mechanism controls the voltage and modulates the voltage applied across the network thereby controlling the quantity of thermal energy transferred between the inner core and the metal piping.