The SMC AS elbow air flow control valve is made of polybutylene terephthalate (PBT) plastic and nickel-plated brass with a push-to-connect tube fitting on the inlet port and male National Pipe Taper (NPT) threads with sealant on the outlet port. The valve body is made of PBT for strength and light weight, and the internal metal parts are made of nickel-plated brass for resistance to corrosion. This valve has NPT threads with polytetrafluoroethylene (PTFE) sealant on the outlet for creating a tighter seal than straight threads, and the push-to-connect fitting on the inlet allows a one-touch connection to nylon, soft nylon, or polyurethane tubing. This valve is designed to be located upstream of the cylinder for meter-in control, and the knob provides ten needle rotations for precise manual adjustment of the air flow. 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, and a retainer to help prevent loss of the needle.

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.