When preparing to light off a cold boiler equipped with a return flow fuel oil system, the recirculating valve directs the flow of oil __________.

Correct Answer: Option A — back to the suction side of the service pump

In USCG Motor Plants (Diesel Engineering), regarding 'When preparing to light off a cold boiler equipped with a return flow fuel oil system, the recirculating valve directs the flow of oil', the correct operational principle is: 'back to the suction side of the service pump'.