Question 259General Subjects - Assistant Engineer70% to pass
In the illustrated huddling-chamber safety valve, what statement is true concerning the opening and closing forces acting upon the disc? Illustration SG-0018
AI Explanation
The correct answer is C.
The spring force acting downward on the disc is a valve opening force, and the sensed pressure acting upward on the disc is a valve closing force. This is because the spring force works to push the disc open, while the sensed pressure works to push the disc closed, in order to maintain the desired pressure in the huddling-chamber safety valve.
The other options are incorrect because they describe the forces in the opposite way. The spring force should act to open the valve, not close it, and the sensed pressure should act to close the valve, not open it.
Related Questions
#257 Referring to the illustrated huddling-chamber safety valve, what statement is true concerning the adjustment of blow down? Illustration SG-0018 #258 Which of the following listed valves would require "blow down" to insure proper operation and prevent damage due to repeated and rapid opening and closing? #260 Referring to the illustrated pneumatically operated diaphragm actuated control valve, what statement is true? Illustration GS-0051 #261 Suppose the illustrated pneumatically operated diaphragm actuated control valve is used to control the fuel oil outlet temperature of a steam-heated heavy fuel oil heater by controlling the steam flow. What would be the result if the stem packing was over-tightened and the stem was unable to vertically move in either direction? Illustration GS-0051 #262 Suppose the pilot controller for the illustrated pneumatically operated diaphragm actuated control valve is supplied with 20 psig control air and is designed to operate the valve with a pilot pressure ranging from 3 to 15 psig. What would be the indication of a properly adjusted spring