SRQ Quick Exhaust Valve is a specific device used in conjunction with solenoid valves or positioners whenever a quick opening and/or closing function is required. It increases the speed of the actuator without hunting as the air to be discharged from the actuator is exhausted to the atmosphere directly from the large derivative unit outlet and not through the positioner. Whenever a very high actuator speed is required, two derivative units can be installed in parallel on the same line.