Question 75Steam Plants - Assistant Engineer

The correct answer is C) Superheater support tubes. In a D-type boiler, the superheater support tubes are located in the generating tube bank. The generating tube bank is the area of the boiler where the steam is generated from the water. The superheater support tubes help to hold the superheater in place, which is responsible for increasing the temperature of the steam before it enters the turbine or engine. The other options are incorrect because waterwalls, recirculating tubes, and downcomer tubes are not located in the generating tube bank. Waterwalls and downcomer tubes are part of the boiler's water circulation system, while recirculating tubes are used in some boiler designs to improve efficiency.