Valve Positioners Designed For Toughest Challenges

Where industrial applications demand the highest levels of safety and reliability process control systems need to be able to withstand the effects of the most challenging potential threats. Series 3731 explosion-proof valve positioners from Samson Controls (UK) are housed in a rugged enclosure which, even if an explosive atmosphere forms inside the enclosure and ignites the enclosure will withstand the explosion preventing the passage of flames out to the explosive surroundings.

In addition to their exceptional durability these intrinsically-safe positioners provide outstanding accuracy and are easy-to-operate, a single rotary pushbutton is all that is required for start-up; turn to select parameters and push to activate them. This convenient method of operation is still possible in hazardous areas because the shaft design of the rotary pushbutton through the housing is explosion-proof. Also, the design of the enclosure with its separate terminal compartment, allows direct cable entry or connection without spark barriers for cable conduit systems.

An easy-to-read liquid crystal display ensures that relevant data is visible at a glance and regardless of the valves mounting position, data is never displayed upside down because the display can be rotated by 180° at the push of a button.

The analogue control helps the positioner achieve outstanding positioning accuracy which allows the microprocessor to concentrate on other tasks. The positioners can be conveniently configured on-site, or by using HART communication, while the additional option of fully integrating EXPERT valve diagnostics into the positioner, provides all the necessary information for predictive maintenance.