Ningbo Kaiven Pneumatic Cylinders Co.,Ltd >> Air Solenoids

There are two types of solenoid-activated air valves: pneumatic, or pilot operated, and direct acting. Direct acting solenoid valves have a more basic construction; a plunger or sealing pin blocks the passage of air through the valve, and a solenoid coil atop the plunger moves it when activated. Normally open (NO) valves move the plunger to block flow when activated, while normally closed (NC) valves activate the plunger to release flow. Piloted solenoids combine a pneumatic valve with a small solenoid vent chamber, allowing the valve to function pneumatically through changes in gas pressure while still being activated by solenoid.

Both pneumatic and direct acting air valves can be manufactured to have multiple outlets. Two-way pneumatic valves are used commonly in space heating and cooling, and three or more valve outlets may be used to heat multiple apartments from the same source. Pneumatic air valves are convenient for multiple-line valves, since air can be easily compressed and directed to different outlets using the basic principles of air compression. Solenoid pilots make applications like space heating easy to automate, since solenoids can be remotely activated, programmed or triggered. Hysteresis, or path-dependent memory, can be programmed into the solenoid, making it so that air solenoid valves can regulate temperature or pressure with little or no human effort.