Valve automation in oil, gas, and petrochemical facilities requires more than selecting an actuator by torque. Engineers must also consider hazardous-area classification, enclosure protection, control signals, power supply, valve operating torque, and the required valve position during a power failure.
For ball valves, butterfly valves, and other quarter-turn valves installed in potentially explosive atmospheres, selecting the right explosion-proof electric actuator therefore depends on verifiable technical parameters rather than general claims about reliability.
Oil and gas facilities may contain flammable gases or vapors. Electric equipment installed in these environments must therefore match the applicable hazardous-area classification.
The DCL explosion-proof actuator range is specified with ATEX/IECEx protection including Ex db h IIC T4 Gb and Ex h tb IIIC T135°C Db. Under the CSA classification system, the product documentation also lists Class I, Division 1, Groups C and D T5/T6 and Class I, Zone 1, AEx db IIC T5/T6 Gb.
For an oil and gas project, the first selection step should therefore be identifying whether the installation is in Zone 1, Class I Division 1, or another classified location. The actuator certification must then be checked against that specific requirement.
Two valves with the same nominal diameter may require different operating torque because of seat material, pressure, process medium, manufacturing design, or operating condition.
The DCL-Ex series ranges from DCL-Ex05 to DCL-Ex300, with standard output torque from approximately 50 Nm to 3000 Nm. The DCL-Ex300 is specified with a maximum torque of 3900 Nm.
The product documentation also recommends using actual torque data supplied by the valve manufacturer and applying approximately a 1.1–1.3 torque allowance factor when selecting the actuator.
This approach is particularly relevant for large ball valves, butterfly valves, or valves that may experience higher breakaway torque after remaining in one position for an extended period.
DCL explosion-proof electric actuators are specified with an IP68 enclosure and an ambient temperature range of -25°C to +55°C. Depending on model and configuration, available power supplies include DC24V, AC110V, AC220V, and AC380V.
For process control applications, Type E/GEY modulating versions accept 4–20mA DC, 1–5V DC, or 2–10V DC input signals and provide 4–20mA DC position feedback. The documented basic error is no more than ±1%, with repeating error of no more than 1%.
These specifications make the actuator suitable for valve positioning in flow, pressure, temperature, and level control loops where proportional control is required.
Optional functions include Modbus communication, over-torque protection, dehumidifying heaters, and fail-safe return.
A hazardous-area valve may also need to move to a defined position when external power is lost.
The optional DCL fail-safe system can drive the valve to a preset fully closed, fully open, or current position when an abnormal power interruption occurs. Energy is stored internally using a super-capacitor or battery, depending on actuator model. The documentation specifies a full-stroke driving capability of at least four cycles.
This function can be considered where the process design requires a defined valve position during loss of electrical power.
For oil and gas valve automation, actuator selection should combine hazardous-area certification, valve operating torque, power supply, control mode, feedback requirements, environmental protection, and fail-safe strategy.
The DCL explosion-proof electric actuator range combines IP68 protection, hazardous-area certifications, 50–3000 Nm standard output torque, 4–20mA modulating control, and optional Modbus and fail-safe functions.
For engineering selection, these measurable specifications provide a stronger basis than broad statements such as “high performance” or “high reliability.”