Air lock valve Accessories for pneumatic actuators

Three-break protection scheme

The safety factor is usually an important factor that needs to be paid attention to in many applications of actuators. 

In the event of interruption of gas source, power supply and signal, the actuator shall immediately reach the process safety position (full on, full off or reservation). 

The core of the three-break protection scheme is the air-locked valve. 

The air lock valve consists of a pneumatic pressure switch and two three-ventilation control valves. 

A calibration spring is arranged in the pressure switch to adjust the pressure of the pilot gas source. 

When the working pressure is lower than the set value, the pressure switch action will discharge the lead air, and the switching path of the three-way gas control valve will lock the actuator on the spot. When the working pressure is restored and 1 bar higher than the set value, the pneumatic pressure switch turns on the pilot gas source, and the switching path of the three-way gas control valve is reopened. 

This high pressure difference can avoid continuous air lock caused by pressure fluctuation. 

When the air source is cut off, the air lock valve acts directly to realize the gas lock protection. 

When the signal is cut off, the electronic switch cuts off the power supply of the solenoid valve, the solenoid valve reverses the exhaust, the pilot gas source of the air lock valve is reduced, and the gas lock protection of the air lock valve is operated to realize the power cut off protection. 

The pneumatic actuator equipped with intelligent locator, the function of breaking signal protection is realized by intelligent locator, and the pneumatic control circuit does not need to be equipped with electronic switch and solenoid valve. 

When the power is cut off, the solenoid valve reverses the exhaust, the pilot gas source of the air lock valve is reduced, and the gas lock protection of the air lock valve is operated to realize the power cut off protection. The pneumatic actuator with intelligent locator works without power supply, so the power cut-off has no effect on the actuator. If the air lock valve is used in combination with the gas tank, the actuator can move to the full open or closed position when the gas source is interrupted. 

When the fast opening or closing function and the three-break protection function are required, the design of the pneumatic circuit can install a multi-channel air lock device in parallel on an actuator to meet the control and safety requirements. 

Technical specifications 

> material: aluminum 

> Design pressure: Max. 10 bar 

> working pressure: 2 / 7 bar 

> operating temperature:-20 / 150 ℃ (other temperature environments can be customized) 

> pilot pressure setting range: 2 / 5 bar 

> pilot pressure interface: 1 / 8 "