Suppose this valve control system has a problem. The control valve (LV-104) does not move to the full-open position as it should when the solenoid is de-energized, although it will move when the 4-20 mA current signal to the I/P transducer is varied while the solenoid is energized:
Solenoid Valves Problems
Identify the likelihood of each specified fault for this circuit.
Consider each fault one at a time (i.e. no coincidental faults), determining whether or not each fault could independently account for all measurements and symptoms in this circuit.
The below tables shows the solutions, showing possible faults and Impossible faults.
Share Your comments on the below answers.