Seeking advice on an air circuit diagram
Thread Content
A friend who works with instruments, could you help me take a look at this diagram? In this diagram, is the solenoid valve in a de-energized or energized state? Is it de-energized by default? When it’s de-energized, is the valve open or closed? It’s related to the process flow, and I really can’t understand it. Thank you
This post was last edited by ylb913 on 2018-6-9 at 14:30. Only 6 in the diagram is a solenoid valve. In the event of a power loss, the air behind valve 6 is released; valve 5 loses its control air, so it remains closed, while the valve above it stays open, and the regulating valve closes. Today’s valves are required to operate while under voltage, and this valve is designed to open while powered. Of course, whether the solenoid valve is energized or not is controlled by the DCS; it is the DCS that controls the opening and closing of the valve. It is a safety measure to have it shut down in the event of a sudden power failure.
This post was last edited by ylb913 on 2018-6-9 at 15:21. When there is wind, the valves below 3 are open; the cylinder valve is controlled by solenoid valve 6. 4 When there is no wind, the air paths of the valves below 3 and 3 are simultaneously cut off, and the valve position of the cylinder remains unchanged. In the absence of a gas storage tank 10, when the instrument air is stopped, the valve position remains unchanged, and it is also not possible to alter its on/off state. 10 is the air storage tank, and 9 is the check valve. The outlet of the air storage tank is a valve that can be operated manually on-site (valve 8 is usually left open). In the event of an interruption in the air supply, air can be supplied temporarily from the air storage tank; at this time, the operation of the valve is still controlled by solenoid valve 6, but there is a limit to the number of times it can be opened or closed, as each operation results in some air being consumed (released). When the pressure of the instrument air in the storage tank becomes insufficient (or when valve 8 is closed), the system returns to a state with no air storage tank.
I’m here to learn*, to gain knowledge
In the diagram, under normal conditions the solenoid valve is not energized and the valve is in a closed state； The valve opens when interlocked and powered
This is similar to the compressor oil circuit I learned about; it’s also electromagnetic
Valve 6 is a solenoid valve; when powered, it opens the air path, and when powered off, it closes the air path (it controls the control air for valve 5 placed side by side).