The SMC AS in-line air flow control valve is made of polybutylene terephthalate (PBT) plastic and nickel-plated brass with push-to-connect tube fittings on the inlet and outlet ports. The valve body is made of PBT for strength and light weight, and all metal parts are made of nickel-plated brass for resistance to corrosion. This valve is designed to mount on a control panel using the hexagonal panel nut, and the knob provides ten needle rotations (eight for the M5 body size) for precise manual adjustment of the air flow. The push-to-connect fittings allow a one-touch connection to nylon, soft nylon, or polyurethane tubing. The maximum operating pressure is 145 pounds per square inch (psi), and the ambient and fluid temperature range is 23 to 140 degrees F (-5 to 60 degrees C). This air flow control valve has a lock nut to lock the needle setting.

Air flow control valves (also called speed controllers) regulate the flow of compressed air into or out of pneumatic cylinders to control the speed of motion of the piston in the cylinder. The valves have an adjustable metering needle and a check valve to control the flow in only one direction. Air entering the valve is blocked by the check valve and forced to pass through the needle valve, and the position of the needle is adjusted to determine the rate of flow. Pneumatic systems with cylinders are used for applications such as truck and train air brakes, air compressors, and tools for mining, manufacturing, and construction.

SMC Corporation of America, a U.S. subsidiary of SMC Corporation in Japan, was founded in 1959 in Tokyo. SMC manufactures actuators, valves, airline equipment, connector fittings, electrical products, vacuum products, dryers, temperature control chillers, and a broad range of related accessories. SMC Corporation of America is headquartered in Noblesville, IN, and meets International Organization for Standardization (ISO) 9000:2000 standards.