Differences and Selection of Electric vs Pneumatic Control Valves

2022-07-15
天津球阀

As the name suggests, the main difference is power supply vs air supply.
Electric control valves use a motor; pneumatic ones use compressed air.
Fundamentally similar, only different drive modes.
Electric valves have 0.3% basic error and sensitivity, require no extra air supply, and are intrinsically safe, suitable for high-explosion-proof sites.
Below are the features of electric and pneumatic control valves

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I. Features of Electric Control Valves

Consist of electric actuator + control valve.
  1. Light weight, attractive appearance.

  2. Versatile, simplified design, easier management and maintenance.

  3. Large rangeability up to 100, stable regulation from 10%–90% opening.

  4. Stable operation, high reliability, solves leakage problems.

  5. Excellent shut-off performance, nearly zero leakage.

  6. Good pressure resistance, anti-clogging, simple flow path, high Kv value, self-cleaning.

  7. Approximate equal-percentage flow characteristic, energy-saving.

  8. Powered by electricity, no air supply needed, convenient and economical.

  9. High precision (resolution 1/1000), low operating cost, maintenance-free.

  10. Optional PTFE or ceramic lining for high corrosion & wear resistance.

II. Features of Pneumatic Control Valves

Consist of pneumatic actuator + control valve.
  1. High-strength aluminum cylinder, long service life, low friction.

  2. Compact modern design, cost-effective.

  3. High-quality bearings, low friction, quiet, long life.

  4. External stroke adjustment ±5°.

  5. Die-cast aluminum piston & end cap, light and strong.

  6. Suitable for high/low temperatures with different seals.

  7. Multi-turn and three-way actuators available.

  8. Simple control, intrinsically safe, explosion-proof without extra measures.

  9. Lower accuracy and sensitivity to be improved.

Summary

  • Electric: 0.3% error & sensitivity, no air supply, not for high-explosion areas.

  • Pneumatic: 0.5% error & sensitivity, needs air supply, intrinsically safe, ideal for high-explosion sites.

Selection Guide

  1. Cost: Pneumatic valves are cheaper.

  2. Application: Pneumatic is widely used in chemical & petrochemical industries (explosion-proof, low failure rate); electric is preferred in power plants.

  3. Speed: Pneumatic acts faster; electric is slower.

  4. Precision: Electric has higher precision and built-in functions.

  5. Auxiliaries: Pneumatic needs compressor and signal converters.

  6. Usage: Electric suits smooth, stable high-pressure water systems.