double acting cylinder Function of a double acting cylinder without damping. Function of a double acting cylinder with damping. Both throttle valves are mobile, which means that differing damping figures can be set. description ordernumber 431 see also: hydraulics: directional control valve (connection diagram and drawing) pneumatics: 3/2-, 4/2- and 5/2-port directional control valves transmission ratio (speed, number of teeth) Path-measuring system (made-up of two models)