Linear

Linear electric actuators are used on valves with axial stem travel, primarily globe control valves, heating/cooling control valves, and process valves where electric actuation is required and no compressed air system is available. Selection should be based on stem thrust in push or pull direction, valve stroke, travel speed, control signal, supply voltage, duty cycle, and valve behavior under differential pressure.

This category includes ARI PREMIO, PREMIO PLUS 2G, and PACO actuators. PREMIO units cover applications requiring 2.2-5 kN or 12-25 kN thrust, with maximum stroke up to 50 mm or 80 mm depending on version. Available supply options include 230 V AC, 24 V DC, and 24 V AC/DC. Enclosure protection is IP65, with ambient temperature range from -20 to +70 °C. Standard features include force switches, a manual handwheel, stroke indication, and provision for position accessories such as potentiometers or electronic position indicators.

PREMIO PLUS 2G actuators are used where modulating position control is required via 3-point, 0-10 V, or 4-20 mA signals. These versions use a BLDC motor, provide stroke up to 50 mm in the 2.2-5 kN range and up to 80 mm in the 12-25 kN range, and allow adjustable travel speeds. Automatic stroke adaptation to the connected valve is also specified.

ARI PACO actuators are intended for smaller control valves, with 0.85 kN thrust and stroke up to 20 mm. Enclosure rating is IP54 and operating temperature range is 0 to +50 °C. Depending on version, control is by 3-point or analog 0-10 V / 2-10 V signal. Standard functions include manual override, 0-10 V DC feedback, and valve blockage detection.

During actuator selection, the design review should verify thrust margin, stroke matching, packing friction, fail-position requirements, response time, signal wiring, moisture protection, and accessibility for manual operation and periodic end-stop inspection. Valve shut-off force, seat load, leakage class, and service conditions should also be checked against process differential pressure and operating temperature.