Which of the tools listed must be used when retightening the plate type heat exchangers used in the device shown in the illustration? Illustration MO-0110

Correct Answer: Option C — Steel ruler or tape measure

Plate-type heat exchangers require precise compression of the plate pack to ensure gasket integrity. Manufacturers specify a target dimension for the tightened plate pack, which must be measured using a steel ruler or tape measure. Over-tightening beyond this dimension will crush the gaskets, leading to leaks and potential plate damage.