A heating apparatus for heating a metal pipe or a metal pipe weld joint, comprising at least one heating collar configured for being disposed around the pipe or weld joint, the at least one heating collar configured for heating the metal pipe weld joint to a stress test temperature or to a post weld treatment temperature, wherein the at least one heating collar further comprises a resistance wire network which is capable of creating thermal heat energy when voltage is applied across the wire network, an inner core configured to be contiguous with the pipe or weld joint, to absorb the thermal heat energy from the network and to transfer the thermal heat energy to the pipe or weld joint, a protective layer providing a protective outer covering for supporting and protecting the at least one heating collar from the external environment, the protective layer further comprising fastening means for securing the at least one heating collar securely around the pipe or weld joint, an inner core for absorbing thermal heat energy from the network and transferring the thermal heat energy to the pipe or weld joint, a heat transfer element, the heat transfer element contiguous with the inner core and configured to transfer thermal heat energy from the inner core to the pipe or weld joint, an outer cover, the outer cover providing a thermally conductive heat transfer substrate for transferring thermal heat energy from the inner core to the pipe or weld joint, and an insulating layer, the insulating layer providing a heat insulating layer for protecting the hands of a welding operator from direct thermal contact with the heat transfer element, the improved heating apparatus characterised by: a) a controller unit configured for connecting to a source of electrical power, the controller unit operatively coupled to the at least one heating collar and further configured for controlling the supply of electrical power to at least one heating collar; b) a contactor disposed in the controller unit for controlling the supply of electrical power to the at least one heating collar; c) a digital controller disposed in the controller unit configured for turning the contactor on and off, the digital controller further comprising a program for turning the contactor on and off at predetermined times wherein the at least one heating collar can heat the pipe or weld joint at the predetermined times; and d) a thermocouple disposed in the at least one heating collar, the thermocouple configured to measure temperature in the at least one heating collar during a heating operation of the pipe or weld joint, the thermocouple operatively coupled to the digital controller wherein the digital controller is programmed for turning the contactor on and off in response to the temperature measured by the thermocouple to heat the pipe or weld joint to predetermined temperatures at the predetermined times, wherein the digital controller is programmed to turn the contactor on and off to heat the metal pipe weld joint to the stress test temperature of by raising the temperature to 1100°F (593.3°C) over 30 minutes, keeping the temperature at 1100°F (593.3°C) for 2 to 4 hours and then decreasing the temperature to room or atmospheric temperature over 30 minutes, or to heat the metal pipe weld joint according to a post weld treatment operation by first heating the metal pipe weld joint to 200°F (93.3°C) and then heating the metal pipe weld joint to 1150°F (621.1°C) over a 30-minute heating period and holding this temperature for 2 to 4 hours followed by a 30-minute cool-down period to 200°F (93.3°C). a) a controller unit configured for connecting to a source of electrical power, the controller unit operatively coupled to the at least one heating collar and further configured for controlling the supply of electrical power to at least one heating collar; b) a contactor disposed in the controller unit for controlling the supply of electrical power to the at least one heating collar; c) a digital controller disposed in the controller unit configured for turning the contactor on and off, the digital controller further comprising a program for turning the contactor on and off at predetermined times wherein the at least one heating collar can heat the pipe or weld joint at the predetermined times; and d) a thermocouple disposed in the at least one heating collar, the thermocouple configured to measure temperature in the at least one heating collar during a heating operation of the pipe or weld joint, the thermocouple operatively coupled to the digital controller wherein the digital controller is programmed for turning the contactor on and off in response to the temperature measured by the thermocouple to heat the pipe or weld joint to predetermined temperatures at the predetermined times, wherein the digital controller is programmed to turn the contactor on and off to heat the metal pipe weld joint to the stress test temperature of by raising the temperature to 1100°F (593.3°C) over 30 minutes, keeping the temperature at 1100°F (593.3°C) for 2 to 4 hours and then decreasing the temperature to room or atmospheric temperature over 30 minutes, or to heat the metal pipe weld joint according to a post weld treatment operation by first heating the metal pipe weld joint to 200°F (93.3°C) and then heating the metal pipe weld joint to 1150°F (621.1°C) over a 30-minute heating period and holding this temperature for 2 to 4 hours followed by a 30-minute cool-down period to 200°F (93.3°C).