Abstract: A process equipment heating system has a group of electric heaters and a heater checking system. The heater checking system is configured to determine a resistance value R1 for the group of electric heaters, compare the resistance value R1 with a reference resistance value RR and judge a fault condition if the resistance value R1 differs from the reference resistance value RR by more than a predetermined amount.

Abstract: A fault indicating circuit for an electric heater has a first branch to conduct a supply of electrical ,energy to the electrical heater and includes a temperature sensitive device to interrupt the supply of electrical energy to the electric heater when exposed to a temperature exceeding a set temperature. The fault detecting circuit has a second branch that includes at least an element of a fault indicating device. The first branch has a first resistance R1, the second branch has a second resistance R2 and the two branches are, electrically in parallel.

Abstract: The invention is directed to a pipe heater which includes a heater body to be secured against a pipe, a securing strap system operable to secure the heater body to the: pipe and a self-amalgamating material element provided on the pipe heater to be engaged with a compatible material portion of the pipe heater to lock the securing strap system in a securing condition. The heater body is provided with at least one heating element.