Question 91General Subjects - 1st Asst/Chief

The correct answer is A) Steel ruler or tape measure. When retightening the plate type heat exchangers, a steel ruler or tape measure would be the appropriate tool to use. This is because the retightening process typically involves checking and adjusting the spacing between the plates to ensure proper heat transfer and prevent leaks. Using a steel ruler or tape measure allows you to accurately measure and verify the specified gap dimensions, which is a crucial step in the maintenance of plate type heat exchangers. The other options, such as a pneumatic impact wrench (B), cantilever wrench (C), or torque wrench (D), are not the appropriate tools for this specific task. These tools are more suitable for other types of maintenance or repair work, but they do not provide the necessary precision and control required for properly retightening the plate type heat exchangers.