Keep the air source in place in case of a failure – how to achieve this?
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Hello everyone!~ The air supply issue persists; what methods can be used to resolve it? Would using a dual-coil solenoid valve help? Or perhaps adding a positioner to the pneumatic actuator? Please ask the experts for help @!~
For cylinder valves, in order to remain in place in the event of a gas supply failure, a design without spring return should be used; instead, a pneumatically bidirectional driving mechanism is appropriate. In such a mechanism, once the gas supply is interrupted, there is no driving force left, so the valve remains in its original position
Thank you! You’re absolutely right. So when can a two-coil solenoid valve be useful? Does it help in maintaining a position?
What was said on the 2nd floor is not entirely correct. When a double-acting cylinder is used, it can only stop at its final position in the event of a loss of air pressure, but this position is not necessarily maintained, especially when there is a large pressure difference before and after the valve. The medium exerts force on the valve element (such as the disc in a butterfly valve or the valve core in a globe valve), and over time this can cause displacement. Therefore, regardless of the type of cylinder used, the most reliable way to maintain the position in the absence of air pressure is to use a position-preserving valve. This type of valve is installed at the inlet and outlet of the cylinder’s air supply, with its pilot port connected to the main air supply line. When the main air pressure drops to the set level, the position-preserving valve cuts off the air supply to the cylinder, thereby maintaining its position. A two-coil solenoid valve has two functions: one is to maintain the position in the event of a power loss, and the other is related to the interlocking requirements of the control system.