What will happen to the pneumatic valves in the event of a sudden power outage and a disruption in the supply of instrument air?
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What will happen to the pneumatic valves in the event of a sudden power outage and a disruption in the supply of instrument air?
Come, let’s recall some major historical events together. Around 6 p.m. on July 16, 2010, an oil pipeline belonging to PetroChina exploded and caught fire near Dalian New Port in Jinzhou District, Dalian. The fire hero manually closed a tank valve, turning it 80,000 times. This is the answer.
In the event of a power loss or gas supply interruption, the valve will enter a fault state. There are three types of valve fault states: FO, FC, and FL, which correspond to open in an emergency, close in an emergency, and remain in place in an emergency. This means that under emergency conditions the valve will open, close, or stay in its current position
The supply of instrument air is usually provided through multiple channels, and there are also air storage tanks designed for specific purposes or other functions, which ensure a continuous supply over a certain period of time. But if there are special requirements, manual processing can be done during this period. For most pneumatic control valves, the amount of loss is extremely small, and the air tank supply can ensure a long operating time; different approaches are adopted depending on the setup of the instrument air supply. It is best to consult the relevant operating procedures for reference.
Check whether it is a normally open valve or a normally closed valve, and whether it can maintain its state after the air supply is cut off; otherwise, it will return to the state with no air supply.
It depends on the valve: for air-operated valves, when the air supply is cut off, the valve closes; for pressure-operated valves, when the pressure is removed, the valve opens
When power and gas are cut off, the gas open valve closes completely; when power and gas are cut off, the gas close valve opens completely.
I see someone has answered correctly! When servicing and adjusting air-on valves and air-off valves, just be careful not to make mistakes; in emergency situations, it is necessary to verify the status of the key valves on site.
The air-on valve will close, the air-off valve will open, and the position maintaining valve will not move