Compact Pneumatic Actuators for Quarter Turn Valves, The EPA pneumatic actuators provide a rugged and compact solution for quarter turn valve actuation. The scotch yoke design offers high torque output while reducing maintenance requirements. Available in both double and spring return configurations, the modular design can be quickly and easily converted in the field. Flowbus is able to make the EPA actuators a high quality, reliable actuator,utilizing tried and tested methods of operation combined with the latest innovations in technology.