The CVS Series 657 Actuator is a reverse acting, spring opposed diaphragm actuator used for automatic operation of control valves. Suitable for on/off or throttling service.
When the loading pressure is increased within a direct-acting diaphragm actuator the actuator stem moves downward, compressing the spring. A decrease in pressure will cause actuator stem to move upward with the decompression of the spring.
The valve plug action of the CVS Type 657 Actuator can be set to “push down to close” or “push down to open” and will then either open or close the control valve upon failure of the loading pressure. When the loading pressure fails, the diaphragm of the actuator moves to the extreme upward position and performs the selected action.
