1. What Is an Electric Gate Valve?
An electric gate valve is an automated isolation valve consisting of a gate valve body and a multi-turn electric actuator. The actuator receives an electrical command, rotates the stem nut and drives the gate vertically into or out of the flow path, giving full open or full closed positions without manual effort. Gate valves offer very low flow resistance when fully open and a straight-through bore, which makes them the preferred isolation valve for large pipelines. The electric drive adds remote control, DCS/PLC integration, position feedback and unattended operation.
Two distinct product families carry the name "electric gate valve" and must not be mixed up in specifications: metal-seated steel gate valves (API 600 / ASME B16.34, Class 150–2500, for steam, oil, gas and chemicals) and soft-sealed (resilient-seated) gate valves (rubber-encapsulated wedge, EN 1074-2 / BS 5163, PN10–PN25, for water and wastewater). They differ in seats, materials, pressure classes and temperature limits.
2. Technical Data and Standards
| Parameter | Metal-Seated Series (API 600) | Soft-Sealed Series (Water) |
|---|---|---|
| Size | NPS 2" – 56" (DN50 – DN1400) | DN40 – DN600 (larger on request) |
| Pressure rating | Class 150 – 2500 | PN10 / PN16 / PN25 |
| Body material | A216 WCB, A352 LCB, A351 CF8/CF8M/CF3/CF3M, alloy steels | Ductile iron / cast iron, epoxy-lined |
| Seat / wedge | Metal seat, 13Cr or cobalt-based hardfacing | EPDM or NBR encapsulated wedge |
| Temperature | -29°C to 425°C (WCB); cryogenic grades available | -10°C to +90°C typical (EPDM) |
| Design standards | API 600, ASME B16.34 | EN 1074-2, BS 5163 |
| Face-to-face | ASME B16.10 / EN 558 | EN 558 / ISO 5752 |
| Flange connection | ASME B16.5 / ASME B16.47 | EN 1092-2 / ISO 7005-2 |
| Testing | API 598 / ISO 5208 | EN 12266-1 / ISO 5208, Rate A |
| Actuator | Multi-turn electric: 24V DC / 220V AC / 380V AC; on/off or modulating with 4-20 mA feedback; IP65/IP67; explosion-proof Ex d optional; manual override included | |
Pressure-temperature ratings follow ASME B16.34 for the metal-seated series; for the soft-sealed series the elastomer sets the service limits.
3. Working Principle and Actuator Features
Valve mechanism: the gate moves perpendicular to the flow direction; the stem is raised or lowered by the actuator through a threaded stem nut. When fully open, the gate clears the full bore so the flow path is unobstructed - this is why gate valves have minimal pressure drop. When closed, the wedge seats against the body seats to isolate the line.
Actuator features: the electric actuator converts motor rotation into linear stem travel through a worm/worm-gear reduction. Standard features include: torque limiter and thermal overload protection (the motor stops automatically at the seat or at a limit position, preventing damage); open/close limit switches; 4-20 mA position feedback for modulating options; local push-button control with remote (DCS/PLC) override; and a handwheel for manual operation during commissioning or power failure.
4. Application Scenarios
| Industry | Typical Duty | Common Spec |
|---|---|---|
| Water & wastewater | Plant inlet/outlet isolation, distribution networks | Soft-sealed series, DN80-DN600, PN10-PN25 |
| Petrochemical | Crude and product line isolation, tank farm manifolds | API 600, WCB body, Class 150-600, on/off actuator |
| Power generation | Steam and feedwater line isolation | Alloy steel or WCB, metal seat, high-temperature service |
| Municipal engineering | Booster station and water supply network valves | Soft-sealed or metal-sealed per line conditions |
| Food & beverage | Clean media transfer lines | CF8M/316L body, hygienic trim, on/off actuation |
5. Selection Guidelines
Pressure class: choose the class covering the maximum line pressure at the operating temperature (per ASME B16.34 derating); do not oversize - higher classes cost more and need higher actuator torque.
Material: WCB for general service, LCB for low temperature, CF8/CF8M for corrosive media, alloy steel for high-temperature steam; verify media compatibility with the supplier.
On/off, not throttling: gate valves are designed for fully open or fully closed service. Partially opened gates suffer seat and gate erosion from flow, so if regulation is needed, use a globe or ball valve with positioner instead.
Actuator sizing: the actuator torque must exceed the valve stem thrust requirement (seating load plus packing friction) with at least 25% margin; state the voltage, control mode and IP/Ex requirements.
Standards consistency: specify the design standard (API 600 vs EN 1074-2), face-to-face (ASME B16.10 vs EN 558) and flange standard (ASME B16.5 vs EN 1092-2) in one coherent system to avoid interface mismatches.
Frequently Asked Questions
What is the difference between an electric gate valve and an electric ball valve? Both automate isolation, but a gate valve uses linear multi-turn travel and has the lowest pressure drop of any isolation valve; a ball valve is a 90-degree quarter-turn valve that operates faster and is more compact. Gate valves suit large lines and low-loss duties; ball valves suit fast cycling and space-constrained installations.
Which standards apply to electric gate valves? For metal-seated steel gate valves: API 600, ASME B16.34, face-to-face ASME B16.10 / EN 558, testing API 598 / ISO 5208. For soft-sealed water gate valves: EN 1074-2 / BS 5163, testing EN 12266-1 / ISO 5208 Rate A.
Can an electric gate valve be used for flow regulation? No. Gate valves are isolation valves; operating them partially open exposes the gate and seats to erosive flow and can cause vibration and premature failure. For throttling duty, use a globe valve or a ball valve with a positioner.
What actuator options are available? Multi-turn actuators in 24V DC, 220V AC or 380V AC, with on/off or modulating control (4-20 mA input and feedback), IP65/IP67 enclosures, optional explosion-proof (Ex d) construction, torque and limit switches, and manual override.
How do I choose the pressure class? Determine the maximum pressure the valve will see (including surge) at the actual operating temperature, then select the class whose ASME B16.34 rating curve covers it. Remember that high temperature reduces the allowable pressure of the same class.
Can you supply a custom electric gate valve with a specific actuator? Yes. We can match the valve top works (ISO 5210 multi-turn mounting) to the required actuator specification - voltage, control mode, torque, IP/Ex rating and feedback - and provide a full datasheet and torque calculation for your review before production.