Question 178Motor Plants - 1st Asst/Chief

The correct answer is A) increase the fuel oil control valve opening. When the steam pressure drops below a set value on an automatically fired auxiliary boiler with rotary cup atomizers, the combustion control system will increase the fuel oil control valve opening. This action increases the fuel supply to the boiler, which helps to restore the steam pressure to the desired level. The other options are incorrect because: B) increasing the rotary cup speed would not directly increase the fuel supply, C) decreasing the back pressure regulating valve opening would restrict the steam flow, and D) decreasing the supply steam control valve opening would reduce the steam supply, which would further decrease the steam pressure.