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What Is a Butterfly Valve? Structure, Working Principle and Applications

20/04/2026

What Is a Butterfly Valve? Structure, Working Principle and Industrial Applications of Butterfly Valves

Van Bướm Là Gì? Cấu Tạo, Nguyên Lý Và Ứng Dụng

📝 Introduction

A Butterfly Valve is one of the most commonly used industrial valves today. It is widely installed in water supply systems, HVAC, fire protection systems, water treatment plants, food processing, chemical plants, oil & gas facilities, and many other industries.

Butterfly valves are highly popular because of their compact design, fast operation, cost efficiency, and easy installation. They are an excellent choice for medium and large pipeline systems requiring quick shut-off or automated control.

In this article, PM-E.VN helps you understand what a butterfly valve is, its structure, working principle, types, advantages, disadvantages, and how to choose the right butterfly valve.

What Is a Butterfly Valve?

A butterfly valve is a type of valve that uses a circular disc rotating around a shaft to open, close, or regulate flow inside a pipeline.

When the lever or actuator turns 90°, the disc moves from parallel to perpendicular relative to the flow direction.

Other Common Names:

Butterfly Valve
Disc Valve
Quarter-Turn Valve
Lever Butterfly Valve
Gear Operated Butterfly Valve

Structure of an Industrial Butterfly Valve

A butterfly valve typically consists of the following main components:

1. Valve Body

The outer housing connected to the pipeline in wafer, lug, or flanged type.

2. Disc

The internal component used to shut off or regulate fluid flow.

3. Stem / Shaft

Transfers movement from the handle or actuator to the disc.

4. Seat / Seal

Made of EPDM, NBR, PTFE, Viton, etc. to provide sealing and leakage prevention.

5. Operator / Actuator

Lever handle
Gearbox handwheel
Electric actuator
Pneumatic actuator

Working Principle of Butterfly Valve

A butterfly valve works by rotating the disc one-quarter turn (90°).

When Opening:

Turn the lever or activate the actuator → the disc becomes parallel to the flow → fluid passes through.

When Closing:

Rotate back → the disc becomes perpendicular to the flow → flow stops.

For Flow Regulation:

The disc can remain partially open to control flow rate.

Common Types of Butterfly Valves

By End Connection

Wafer Butterfly Valve

Installed between two flanges; the most common type.

Lug Butterfly Valve

Body has threaded lugs for bolting from both sides.

Flanged Butterfly Valve

Used for higher pressure and larger pipeline systems.

By Material

Cast Iron Butterfly Valve
Stainless Steel 304 / 316 Butterfly Valve
Carbon Steel Butterfly Valve
PVC / CPVC / UPVC Butterfly Valve
Special Alloy Butterfly Valve

By Seat Material

EPDM (clean water)
NBR (oil service)
PTFE (chemical service)
Viton (high temperature)

By Operation

Lever operated
Gear operated
Electric operated
Pneumatic operated

Advantages of Butterfly Valves

✅ Compact Design

Lighter and smaller than gate or globe valves of the same size.

✅ Fast Operation

Only a 90° turn is required.

✅ Cost Effective

Economical, especially for large sizes.

✅ Easy Automation

Simple to install electric or pneumatic actuators.

✅ Flow Control Capability

Suitable for shut-off and throttling applications.

Disadvantages of Butterfly Valves

The disc remains in the flow path, causing some pressure loss
Not as bubble-tight as ball valves in some critical applications
Soft seats have temperature and chemical limitations

Industrial Applications of Butterfly Valves

Butterfly valves are widely used in:

Water supply systems
HVAC / Chiller systems
Fire protection systems
Water treatment plants
Food & beverage factories
Chemical plants
Oil & gas facilities
Cement plants
Power plants

How to Choose the Right Butterfly Valve

Based on Media:

Clean water → cast iron + EPDM
Oil → NBR
Chemicals → stainless steel + PTFE
Seawater → SS316 / Duplex

Based on Pressure Rating:

PN10 / PN16
ANSI Class 150

Based on Operation:

Lever: small sizes
Gearbox: larger sizes
Electric / pneumatic: automation systems

Where to Buy Reliable Butterfly Valves?

PM-E.VN supplies:

Wafer butterfly valves
Lug butterfly valves
Stainless steel butterfly valves
Electric butterfly valves
Pneumatic butterfly valves
Genuine imported butterfly valves

✔ Full CO/CQ documentation
✔ Competitive pricing
✔ Professional technical support
✔ Nationwide delivery

Conclusion

A Butterfly Valve is a modern industrial valve solution offering compact size, fast operation, affordable cost, and easy automation. It is an ideal choice for water systems, HVAC, fire protection, chemicals, and many industrial applications.

If you need help selecting the right industrial butterfly valve, contact PM-E.VN for fast and accurate technical support.

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