1. What Is a Butterfly Valve?

A butterfly valve is a quarter-turn valve that uses a rotating disc to control or shut off fluid flow.

When the disc rotates approximately 90°, the valve moves between the fully open and fully closed positions.

A typical butterfly valve consists of:

• Valve body

• Disc

• Stem

• Seat

• Sealing components

• Manual handle, gearbox, pneumatic actuator, or electric actuator

Because of its compact structure and relatively low weight, a butterfly valve is widely used in industrial piping systems, especially for medium- and large-diameter pipelines.

2. Why Are Butterfly Valves Widely Used in Industry?

Butterfly valves offer several practical advantages compared with many other valve types.

Compact Design

The disc rotates inside the pipeline, allowing the valve to have a relatively short face-to-face dimension.

This makes butterfly valves suitable for installations where space is limited.

Lightweight Construction

Compared with many large-diameter gate or ball valves, butterfly valves can provide a lighter solution.

This can simplify transportation, installation, and actuator selection.

Fast Operation

A quarter-turn operating principle allows relatively quick opening and closing.

When combined with a pneumatic or electric actuator, the valve can be integrated into automated process systems.

Large Diameter Capability

Butterfly valves are commonly used in large pipeline applications where a compact and economical shut-off solution is required.

Typical applications include:

• Water treatment

• HVAC

• Cooling water systems

• Chemical processing

• Industrial water systems

• Air and gas pipelines

• General process piping

3. The 8 Key Factors for Butterfly Valve Selection

Choosing a butterfly valve should begin with the operating conditions rather than the valve price.

3.1 Determine the Medium

The first question is:

What will flow through the valve?

Common industrial media include:

• Water

• Air

• Steam

• Oil

• Gas

• Chemicals

• Cooling fluids

• Process fluids

Different media have different requirements for corrosion resistance, sealing materials, temperature resistance, and valve-body materials.

For example, a valve used for clean water may have very different material requirements from one used in a corrosive chemical process.

3.2 Select the Correct Valve Material

Valve-body and internal component materials must be compatible with the operating medium and environment.

Common butterfly valve materials include:

Material selection should not be based on the valve body alone.

The disc, stem, seat, seals, and other wetted components should also be considered.

4. Choose the Right Seat Material

The seat is one of the most important components affecting butterfly valve sealing performance.

Common seat materials include:

• EPDM

• NBR

• PTFE

• RPTFE

• Other elastomer or engineered sealing materials

The correct seat depends on:

• Medium

• Temperature

• Pressure

• Chemical compatibility

• Operating frequency

• Required leakage performance

For example, EPDM is commonly used for water-related applications, while other materials may be more appropriate for oil, chemicals, or higher-temperature service.

Therefore, never select a seat material only because it is commonly used in the same valve size.

5. Check Pressure and Temperature Ratings

A butterfly valve must be able to withstand the actual pressure and temperature of the system.

Common pressure classes include:

• PN10

• PN16

• PN25

• PN40

• Class 150

However, the pressure rating of the valve is not the only factor.

The actual allowable pressure may change depending on:

• Valve material

• Seat material

• Operating temperature

• Medium

• Valve size

• Design standard

For high-temperature applications, the temperature-pressure relationship should always be checked before selecting the valve.

6. Choose the Correct Valve Size

Valve size is normally related to the pipeline diameter, but the valve DN should not automatically be selected simply by matching the pipe DN.

The actual flow requirements should also be considered.

Important parameters include:

• Flow rate

• Pressure differential

• Medium density

• Medium viscosity

• Required flow velocity

• Available pressure drop

• Valve opening percentage

For applications requiring flow regulation, selecting a valve that is significantly oversized may cause the valve to operate mostly near the closed position.

This can reduce controllability and increase sensitivity to small changes in opening.

For simple isolation applications, the selection approach may be different.

7. Consider the Valve Connection Type

Butterfly valves are available with different connection configurations.

Common types include:

Wafer Butterfly Valve

A wafer valve is installed between pipe flanges.

Advantages include:

• Compact structure

• Lightweight

• Short face-to-face dimension

• Cost efficiency

It is widely used in water treatment, HVAC, and general industrial piping.

Lug Butterfly Valve

A lug-type butterfly valve uses threaded or dedicated lugs for connection.

It can be useful when the piping system requires more flexible isolation or maintenance arrangements.

Flanged Butterfly Valve

Flanged butterfly valves provide a direct flange connection.

They are commonly considered when the piping system requires a more robust flange connection or specific installation standards.

The appropriate connection should match the pipeline flange standard and installation requirements.

8. Manual, Pneumatic, or Electric Actuation?

The operating method is another important selection factor.

Manual Butterfly Valve

Manual operation can be suitable for:

• Infrequently operated isolation points

• Simple piping systems

• Applications where automation is unnecessary

For larger valves, a gearbox may be used to reduce manual operating effort.

Pneumatic Butterfly Valve

Pneumatic actuation is widely used in automated industrial systems.

Advantages include:

• Fast response

• Simple automation

• Suitable for frequent switching

• Good compatibility with process control systems

Pneumatic actuators are often used in:

• Water treatment

• Chemical processing

• Manufacturing

• HVAC

• Process automation

Electric Butterfly Valve

Electric actuators are useful when electrical control and precise positioning are required.

They can be integrated into automated systems through appropriate control signals and communication configurations.

The actuator should be selected according to the actual valve torque rather than simply the valve DN.

9. Butterfly Valve Selection by Application

Different industrial applications require different priorities.

The same butterfly valve configuration should not automatically be used for every application.

10. Butterfly Valve vs Ball Valve: Which Should You Choose?

Butterfly valves and ball valves both provide quarter-turn operation, but their strengths are different.

In general:

Choose a butterfly valve when compact design, large diameter, lower weight, and cost efficiency are important.

Choose a ball valve when full-port flow, tight shut-off, or higher-pressure service is a major priority.

The final decision should always be based on the actual operating conditions.

11. KINKO Butterfly Valve Solutions

KINKO provides butterfly valve solutions for industrial flow-control and automated valve applications.

Available configurations can be selected according to the application, including:

• WCB

• CF8

• CF8M

• 304

• 316

• Pneumatic actuation

• Electric actuation

• Manual operation

• OEM/ODM customization

KINKO's butterfly valve solutions focus on:

Reliable Sealing | Corrosion Resistance | Fast Switching | Long Service Life | Easy Automation

For automated applications, KINKO can also provide pneumatic and electric actuator solutions matched to the valve's actual operating torque.

With 21 years of experience in the valve field, KINKO provides complete automated valve solutions for global fluid engineering applications.

Conclusion

Choosing the right butterfly valve requires more than simply matching the valve DN to the pipeline.

A reliable selection should consider:

Medium → Pressure → Temperature → Flow → Material → Seat → Connection → Actuation → Torque → Operating Frequency

For large-diameter pipelines, water treatment, HVAC, cooling systems, chemical processing, and industrial automation, butterfly valves can provide an effective combination of compact design, reliable shut-off, fast operation, and cost efficiency.

When the operating conditions are clearly defined, the valve body, seat, actuator, and connection configuration can be selected as one complete solution—helping improve reliability and reduce long-term operating costs.