Quick exhaust valves are installed at the rod or blind end of a pneumatic cylinder to provide a quick extension and retraction of the equipment. Quick exhaust valves operate by increasing the speed of the pneumatic cylinder's rod in order to expel the exhaust air at the port of the cylinder directly.The function of a quick-release valve (Fig. 23) is to rapidly exhaust air from the controlled device. It is normally located adjacent to the controlled device, rather than requiring exhaust air to return and exhaust through the control valve. This decreases release time.The exhaust pressure control valve detects changes in the pressure of the exhaust gases to properly control the flow of exhaust gases through the EGR system. They are commonly found on vehicles equipped with turbo diesel engines, however they can also be found on the EGR system of gasoline engines as well.

A relay valve is an air-operated valve typically used in air brake systems to remotely control the brakes at the rear of a heavy truck or semi-trailer in a tractor-trailer combination. Relay valves are necessary in heavy trucks in order to speed-up rear-brake application and release, since air takes longer to travel to the rear of the vehicle than the front of the vehicle, where the front service brakes, foot-valve, parking-control valve, and trailer-supply valve (if applicable) are located.

A rotary valve (also called rotary-motion valve) is a type of valve in which the rotation of a passage or passages in a transverse plug regulates the flow of liquid or gas through the attached pipes. The common stopcock is the simplest form of rotary valve.The rotary control valve is a directional control valve actuated in a rotary motion. With high pressure and zero-leak performance, the valve is designed and manufactured to meet your requirements for both topside and subsea applications.They are most often used in air conveyor systems to minimize the loss of pressure across the valve, but rotary valves are also used to meter materials at a controlled feed rate. They work almost exclusively in air systems and function as airlocks, explosion/flame barriers, and process isolators, among other tasks.