Question 126Steam Plants - 1st Asst/Chief

The correct answer is A) Thermostatic. The automatic recirculating valve in the main condensate line is typically controlled by a thermostatic sensor. This sensor monitors the temperature of the condensate and triggers the valve to open or close as needed to maintain the desired temperature in the system. A thermostatic sensor is the appropriate choice as it can directly measure the temperature of the condensate and provide the necessary feedback to the valve. The other options are incorrect because continuity sensors measure electrical continuity, preset electric timing sensors provide a timed response, and pressure sensors measure the pressure in the system, which is not the primary parameter being controlled in this case.