IQS Newsroom Articles on Air Solenoids
Air Solenoids
Air solenoids, similar or identical to pneumatic
valves, are valves which regulate gas or air flow through remote systems or
programming. The solenoid is a magnetized electromechanical coil which moves
either a plunger blocking passage through the valve or, in the case of pneumatic
air solenoids, a small vent which changes pressure in the valve and allows
flow. Because the solenoid coil is activated electrically, the valve can be
switched remotely by programming, sensors or hysteresis (device memory).
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.
Air solenoid valves are used widely for many different industries, and applications
may include compressed air-powered tools such as jackhammers and nailguns,
vacuums, ventilation systems, laser printers and medical and dental air-powered
equipment. Because strong force can be largely self-generated within pneumatic
valve chambers through air compression, air valves are valued for their low
energy requirement as well as their low-maintenance.