Air valves regulate the admission or release of air. One of the most common uses of solenoid valves is as air valves. Typical environments for air valves are in medical and biomedical equipment, analytical instrumentation, semiconductors, HVAC, and other industrial OEM environments. A unique feature of air valves is automatic triggering from remote locations by different voltages, making them useful in rough or hazardous locations.

There are two general types of air valves: direct-acting and pilot-operated. Direct-acting air valves have a plunger that comes in direct contact with the primary opening in the body. This plunger is used to open and close the orifice. A pilot-operated air valve works with a diaphragm rather than a plunger. This type of air valve uses differential pressure to control the flow of fluids. The air-venting valve opens to allow the pressure to equalize and permit the fluids to flow through.

Important details to consider when looking at air valves are proportionality, linearity, frequency response, repeatability, power consumption, leakage, life expectancy, and cost.