The Series 3731 explosion-proof valve positioners are housed in a rugged enclosure which, even if an explosive atmosphere forms inside and ignites, the enclosure will withstand the explosion and will also prevent the passage of flames out to the explosive surroundings. These intrinsically safe positioners also benefit from low power consumption and can be conveniently configured on-site, or by using the HART communication protocol. 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 LCD ensures that relevant data is visible at a glance.