In modern industrial piping systems, valves play a vital role in controlling the flow, pressure, and direction of media such as water, oil, gas, or steam.
They are widely used across industries including petrochemical, power generation, metallurgy, water supply, pharmaceuticals, and energy.
Each valve type has unique structural designs, sealing characteristics, and performance advantages.
Understanding the differences between gate valves, globe valves, butterfly valves, ball valves, plug valves, check valves, safety valves, and control valves is essential for correct valve selection, system safety, and operational efficiency.
1. Gate Valve
Definition and Structure
A gate valve uses a gate or wedge-shaped disc as its closing element.
The gate moves vertically with respect to the flow direction—rising to open and descending to close—thereby allowing or blocking the flow of fluid.
Typical components include the valve body, bonnet, gate (disc), stem, handwheel, and sealing rings.
Advantages
Low flow resistance: When fully open, the fluid passage is almost straight, minimizing pressure loss.
Bidirectional flow: Flow direction is not restricted, suitable for loop or dual-direction systems.
Simple structure & durable design: Easy to manufacture and maintain.
Minimal erosion: When fully open, the sealing surface is less exposed to flow impact.
Disadvantages
Large installation space: Requires considerable height for full stem movement.
Slow operation: Not suitable for frequent opening and closing.
Seal wear: Sliding friction during operation may cause wear, especially at high temperatures.
Applications & Selection Tips
Best suited for on/off service where the valve remains fully open or fully closed for long periods—such as water supply lines, drainage, and large-diameter pipelines.
Avoid using in throttling or flow regulation systems.
When selecting, consider space constraints, flow direction, and whether solid particles are present in the medium.
2. Globe Valve
Definition and Structure
A globe valve controls flow by moving a disc (plug) perpendicular to the seat.
The valve opens as the disc lifts and closes as it presses against the seat.
Flow passes through a curved path inside the valve body.
Advantages
Good throttling performance: Ideal for regulating flow or pressure.
Short stroke: The valve disc lifts only about one-quarter of the seat diameter.
High sealing reliability: Typically has one sealing surface, easy to grind and maintain.
Less friction: Compared to gate valves, wear on sealing surfaces is lower.
Disadvantages
High flow resistance: The flow path changes direction, increasing pressure drop.
Slower operation: Longer stroke and higher resistance to opening.
Applications & Selection Tips
Widely used in steam, chemical, and process control systems that require frequent operation or flow regulation.
Ensure that the system can tolerate higher pressure loss and that the fluid is clean.
Not ideal for large diameters or where low resistance is critical.
3. Butterfly Valve
Definition and Structure
A butterfly valve uses a circular disc mounted on a rotating shaft as its closing element.
When the valve disc rotates about 90°, it opens or closes the flow passage.
Advantages
Compact and lightweight: Ideal for large-diameter pipelines.
Quick operation: Requires only a quarter-turn to open or close.
Low pressure loss: Smooth flow with minimal resistance.
Suitable for various media: Works well with liquids containing small amounts of solids.
Disadvantages
Limited throttling control: Flow increases rapidly as the disc opens.
Lower sealing performance: Not suitable for high-pressure or high-temperature systems (typically ≤300°C, PN ≤40).
Possible cavitation and vibration at partial openings.
Applications & Selection Tips
Common in water treatment, HVAC, and wastewater pipelines.
Select butterfly valves when space is limited, operation needs to be fast, and pressure levels are moderate.
For high-pressure or precise control applications, consider globe or ball valves instead.
4. Ball Valve
Definition and Structure
A ball valve features a spherical closing element (ball) with a hole through its center.
Rotating the ball 90° allows the valve to open or close.
Some V-port ball valves can also regulate flow.
Advantages
Very low flow resistance: Almost full-bore flow.
Fast opening/closing: Only a quarter-turn is required.
Excellent sealing: Reliable in both high- and low-pressure applications.
Long service life: Minimal erosion when fully open.
Disadvantages
Seat material limitations: PTFE seats have limited temperature resistance (typically ≤180°C).
Not ideal for throttling: May cause wear and vibration under partial opening.
Applications & Selection Tips
Ideal for quick shut-off, corrosive media, and high-pressure systems, such as petrochemical pipelines and gas distribution.
Select based on temperature limits of the seat material, desired flow direction, and frequency of operation.
5. Plug Valve
Definition and Structure
A plug valve uses a cylindrical or conical plug to control flow.
Rotating the plug by 90° aligns or blocks the flow passage.
Advantages
Quick operation: Simple quarter-turn movement.
Low flow resistance and compact size.
Good sealing performance: Especially in lubricated types.
Bidirectional flow capability.
Disadvantages
High operating torque: Larger contact area increases friction.
Size limitations: Large-diameter designs are less practical.
Applications & Selection Tips
Used in oil and gas, petrochemical, and mining applications requiring frequent operation and reliable sealing.
Consider plug coating, torque requirements, and maintenance access during selection.
6. Check Valve
Definition
A check valve (non-return valve) prevents backflow in pipelines.
Common types include lift type, swing type, and butterfly type.
Advantages
Automatic operation: Opens with forward flow, closes upon reversal.
Low pressure loss: Especially in swing and butterfly types.
Reliable protection: Prevents pump and system damage caused by reverse flow.
Disadvantages
Water hammer risk: Rapid closure can cause pressure surges.
Installation orientation limits: Especially for swing-type valves.
Wear and noise in frequent flow reversal systems.
Applications & Selection Tips
Essential in pump outlets, water supply, HVAC, and chemical systems.
Choose the type based on flow rate, medium viscosity, and pressure stability.
For systems prone to water hammer, select slow-closing or damped types.
7. Safety Valve and Control Valve
(1) Safety Valve
A safety valve automatically releases excess pressure from a system when it exceeds a preset value, preventing equipment damage.
Advantages:
Protects against overpressure.
Automatically resets after release.
Disadvantages:
Not suitable for viscous or crystallizing media.
May have limited sealing after repeated use.
Applications:
Boilers, pressure vessels, steam systems, and chemical reactors.
Select based on set pressure, medium type, and discharge capacity.
(2) Control Valve
A control valve regulates fluid flow, pressure, or temperature in automated process systems.
Advantages:
High precision control.
Compatible with pneumatic or electric actuators.
Disadvantages:
Complex structure and high cost.
Sensitive to medium impurities.
Applications:
Process automation, chemical production, HVAC control loops.
When selecting, consider signal type (e.g., 4–20 mA), valve characteristics, and actuator response speed.
8. Valve Selection Summary
Selecting the right valve depends primarily on function and operating conditions.
The following guidelines can assist in making an optimal choice:
| Purpose | Recommended Valve Type |
|---|---|
| On/off isolation, low pressure drop | Gate Valve |
| Frequent operation, flow regulation | Globe Valve / Control Valve |
| Large diameter, compact structure | Butterfly Valve |
| Fast shut-off, tight seal | Ball Valve |
| Frequent switching, simple maintenance | Plug Valve |
| Preventing backflow | Check Valve |
| Overpressure protection | Safety Valve |
| Flow or pressure control | Control Valve |
| Fluid mixing or diverting | Mixing Valve |
Conclusion
Choosing the right valve is not just about type—it requires understanding media characteristics, pressure, temperature, flow conditions, and installation space.
A well-selected valve improves system reliability, operational safety, and energy efficiency.
Always consult up-to-date manufacturer specifications and engineering standards before finalizing a valve model to ensure the best match for your application.
