Question 251General Subjects - Assistant Engineer70% to pass
Suppose the illustrated self-contained, internal-pilot, piston-operated temperature control valve is part of the temperature control system for a steam-heated heavy fuel oil service heater for a steam boiler. If there was an increase in demand for fuel by the boiler, what statement correctly represents how the valve would initially respond? Illustration GS-0045
AI Explanation
The correct answer is B.
If there is an increase in demand for fuel by the boiler, the fuel oil heater fuel outlet temperature would decrease, causing the remote bulb pressure to decrease. This would make the control diaphragm flex upward, and through lever action, further open the pilot valve. This allows more heated fuel oil to flow to the boiler, increasing the fuel oil heater fuel outlet temperature back to the desired setpoint.
The other options are incorrect because they do not accurately describe how the temperature control valve would initially respond to an increase in fuel demand by the boiler. Options A and D describe the opposite response, where the valve would close instead of open. Option C describes the valve closing instead of opening in response to a decrease in fuel oil heater fuel outlet temperature.
Related Questions
#249 In the illustrated self-contained, internal-pilot, piston-operated steam pressure- reducing valve, what statement is true concerning the pilot and main valves? Illustration GS-0044 #250 Suppose the illustrated self-contained, internal-pilot, piston-operated temperature control valve is part of the temperature control system for a steam-heated heavy fuel oil service heater for a steam boiler. If there was a decrease in demand for fuel by the boiler, what statement correctly represents how the valve would initially respond? Illustration GS-0045 #252 As it pertains to safety valves, what is the definition of blow down? #253 Referring to the illustrated huddling-chamber safety valve, what statement concerning the blow down adjusting ring #254 Concerning safety valves, what statement is true?