Research Control® Valves BLRA Pneumatic Actuator (Type 766)

The BLRA Pneumatic Type 766 actuator with integral, top-mounted positioner is a pneumatically operated, spring-opposed diaphragm actuator designed specifically to fit the Research Control Valve body-bonnet assembly. The unit is available in two sizes: one for the 1/4" valve and another larger version for the 1/2" through 1" valves. The unit, when equipped with the model BLRA positioner, functions as an air-to-open actuator retracting the stem and opening the valve on an increasing instrument signal. The unit is designed to extend the stem, closing the valve, on a decreasing or loss of instrument signal. A force-balance system is incorporated utilizing the full force of the supply air to position the stem precisely and with a high degree of repeatability. This type actuator should be used when the application calls for high positioning accuracy or when greater force is required over the standard actuator such as in the case of high shutoff pressures or excess packing friction.