Guide to Choosing Industrial Valves Types and Uses

Imagine a vast industrial pipeline system, resembling the human circulatory system, transporting various critical fluids. Valves serve as the "switches" on these pipelines, controlling fluid flow and ensuring the safety and efficiency of the entire system. With numerous types of industrial valves available, how can one select the most suitable "switch"? This comprehensive guide explores the principles, classifications, and applications of industrial valves to assist in making informed decisions during the complex selection process.

As indispensable components in industrial pipeline systems, valves primarily function to open, close, and regulate fluid passages, thereby controlling liquids, gases, powders, and other media. According to the Japanese Industrial Standard (JIS), a valve is defined as equipment with movable mechanisms capable of opening or closing fluid passages to achieve flow control, shut-off, and regulation. Valves find extensive applications across industries including petrochemicals, power generation, metallurgy, pharmaceuticals, food and beverage, and water treatment, playing a crucial role in ensuring safe and stable industrial operations.

Industrial valves can be categorized through various methods based on structure, actuation method, purpose, and material. The following sections detail the primary classifications by structure and application.

Based on the movement mechanism and structural characteristics of valve internals, valves are primarily classified into these types:

These valves operate through rotational movement of the closure element:

• Ball Valves: Featuring a spherical closure element that rotates around the stem axis, ball valves offer simple structure, compact size, low weight, minimal flow resistance, and reliable sealing. Full-bore ball valves provide nearly unrestricted flow, ideal for frequent operation applications. However, they're unsuitable for flow throttling as partial opening may cause seat erosion.
• Butterfly Valves: Utilizing a disc that rotates about the valve axis, butterfly valves present advantages of simple structure, compact size, lightweight, and cost-effectiveness, making them popular for low-pressure, large-diameter systems. Their sealing performance is relatively inferior, making them unsuitable for high-pressure or leak-sensitive applications. The disc partially obstructs flow when open, creating some pressure drop.

These valves employ vertical movement of the closure element:

• Globe Valves: With conical or spherical discs moving perpendicular to the seat, globe valves provide excellent sealing for shut-off or flow regulation. However, they exhibit significant flow resistance and require high operating torque, making them unsuitable for large-diameter pipelines or low-pressure-drop applications.
• Gate Valves: Featuring a wedge-shaped gate moving perpendicular to flow direction, gate valves offer minimal flow resistance when fully open. Suitable for full-open or full-close applications, they have slower operation speeds and inferior sealing compared to other types, limiting their use in high-pressure or frequent-operation scenarios.

A specialized valve type using flexible diaphragms as closure elements, often lined with corrosion-resistant materials. These valves are simple in structure, eliminate packing leakage, and are easily maintained. However, diaphragm materials have limited pressure and temperature tolerance, restricting their use to low-pressure, low-temperature applications.

Based on specific pipeline system applications, valves are categorized as:

• Isolation Valves: For flow shut-off (ball valves, gate valves, globe valves)
• Regulating Valves: For flow/pressure control (control valves, throttle valves)
• Check Valves: For preventing backflow (swing check, lift check valves)
• Safety Valves: For overpressure protection (spring-loaded, lever-type valves)
• Specialty Valves: For extreme conditions (high-temperature, cryogenic, corrosion-resistant valves)

Structure: Comprising body, ball, stem, and seats. The ball features a bore matching pipe diameter that aligns or blocks flow when rotated.

Operation: 90° rotation aligns bore with pipe (open) or perpendicular (closed).

Applications: Widely used in petroleum, chemical, gas, power, and metallurgy industries, particularly for frequent operation.

Structure: Consists of body, disc, stem, and seat with perpendicular disc movement.

Operation: Linear stem motion lifts disc from seat (open) or compresses it (closed).

Applications: Common in systems requiring tight shut-off across multiple industries.

Structure: Includes body, gate, stem, and seats with gate moving perpendicular to flow.

Operation: Full gate retraction enables unrestricted flow; insertion blocks flow completely.

Applications: Preferred for full-open/full-close services in various industrial systems.

Structure: Composed of body, disc, stem, and seals with rotating disc mechanism.

Operation: 90° disc rotation aligns parallel (open) or perpendicular (closed) to flow.

Applications: Dominant in low-pressure, large-diameter systems like water and air handling.

Structure: Features body with corrosion-resistant lining, flexible diaphragm, and actuator.

Operation: Diaphragm compresses against weir (closed) or retracts (open).

Applications: Essential in pharmaceutical, food, and chemical industries for sensitive media control.

• Media Properties: Type, temperature, pressure, corrosiveness, viscosity
• Operating Conditions: Pressure, temperature, flow requirements, cycling frequency
• Pipeline Parameters: Size, connection type, material compatibility
• Control Needs: Automation requirements, precision levels
• Economic Considerations: Cost-effectiveness while meeting performance demands

• Conduct regular inspections of sealing integrity, operational smoothness, and connection tightness
• Promptly address leaks, sticking, or other malfunctions
• Apply periodic lubrication to moving components
• Maintain cleanliness by removing surface contaminants
• Follow proper operating procedures to prevent misuse

The diverse range of industrial valves serves critical functions across numerous applications. Proper valve selection and implementation are paramount for ensuring industrial safety, stability, and operational efficiency. This guide provides fundamental knowledge about valve principles, classifications, and uses to support informed decision-making in industrial settings.