Thermal Hire manufactures a range of Heat Treatment Units designed specifically for preheat and post weld heat treatment applications using electrical resistance heating. The units distribute power from a main electrical supply to electrical resistance heating elements at the correct rated voltage of 60V or 220/240V to suit the application. The units each have the facility to connect up to six independent heating circuits. A fully automatic temperature programmer may be incorporated within the unit which permits temperature control of each circuit in terms of rate of heating, hold temperature & time and rate of cooling. Additionally the equipment may incorporate a multi-channel temperature recording instrument.
The low voltage units are particularly suitable for preheat for welding and for localised heat treatments on pipework butt welds. These are available with air natural cooled transformers rated at 50 kW or 65 kW to suit the application. Each of the circuits is connected to a 60V secondary output and is therefore useful for a range of ceramic pad and preheating elements.
The mains voltage units also have the facility for six circuits which are normally connected to the incoming 3 phase supply at 380/440V. Each circuit is typically rated at 40 kW and comprise star connected heaters such as the rigid channel heater or large flexible ceramic pads suitable for heat treatments on pressure vessels or as a heating source in furnaces.