The compressor emergency shutdown system (ESD) has tripped the natural gas compressor off-line three times in the past 24 hours.…
Suppose this valve control system has a problem. The control valve (LV-104) does not move to the full-open position as…
A engineer needs to write a program for an Allen-Bradley CompactLogix PLC to control a pressure relieving solenoid valve in…
A liquid flow control loop consisting of a flow transmitter (FT) to sense liquid flow rate through the pipe and…
Programmable Logic Controller (PLC) Questions and Answers This PLC is being used to start and stop an electric motor, and…
The following PLC program was written to control the operation of a large electric motor-driven pump. A variety of “permissive”…
Programmable Logic Controller Questions and Answers The following PLC program was written to control the operation of a large electric…
Sketch arrows next to each of the two solenoid valves showing the directions of air flow in the energized (E)…
Determine the “normal energization” states (e.g. NE or NDE) of each solenoid valve in this diagram, assuming the process valve…
Solenoid valve SV-92 plays an important role in this compressor inlet separator control system. Level control valve LV-92 opens up…
