Question 282Steam 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 fitted with rotary cup atomizers, the combustion control system will increase the fuel oil control valve opening. This is done to increase the fuel supply to the boiler, which will raise the steam pressure back to the desired level. The other options are incorrect because: B) increasing the rotary cup speed would increase the air-fuel ratio, not the fuel supply; C) decreasing the back pressure regulating valve opening would decrease the steam pressure, not increase it; and D) decreasing the supply steam control valve opening would reduce the steam pressure, not increase it.