When To Use a Butterfly Valve

A butterfly valve is suitable for low to medium-pressure and variable-flow applications. It is a standard valve for large-diameter pipes that require compact and lightweight valves. Butterfly valves are frequently employed in water distribution, chemical processing, low-pressure applications, and more. They are suitable for throttling and fully open or closed applications, providing efficient flow control and regulation across multiple settings.

A butterfly valve controls fluid flow using a rotating disc attached to a central stem. In the closed position, the disc is perpendicular to the flow, blocking it. Rotating the stem 90 degrees aligns the disc parallel to the flow, allowing passage. The valve can also be partially opened to regulate flow. An o-ring prevents leakage along the stem. Read our butterfly valve overview article for more information on the design and various types of butterfly valves.

Table of contents

• When to use a butterfly valve
• Where are butterfly valves used
• Disadvantages
• Butterfly valves vs ball valves, gate valves, and globe valves
• FAQs

When to use a butterfly valve

A butterfly valve is an excellent choice in various applications due to multiple factors:

• Quick shutoff: Butterfly valves are ideal for rapid opening and closing, making them perfect for emergency shutdowns and fire suppression systems where quick isolation is crucial.
• Limited space requirement: Butterfly valves have a compact and streamlined design, requiring less space for installation than gate valves or globe valves, which is advantageous in tight spaces or where piping systems are congested. They are also cost-effective compared to other valve types.
• Applications involving large pipe sizes: When fully opened, the butterfly valve provides low flow resistance and precise flow control, making it commonly used for regulating large-diameter systems.
• Coarse media: Butterfly valves, depending on the strength of the seal, are suitable for handling media with suspended solid particles, powders, and granules. They are also effective for transporting mud or slurries, minimizing liquid accumulation at the pipe mouth.
• Limited torque requirements: Butterfly valves require less torque due to their quarter-turn operation, allowing for more miniature, more cost-effective actuators than other valves like gate valves.
• Flow regulation: While not as precise as globe valves, butterfly valves can be used for flow regulation and throttling, providing a good balance between flow control and pressure drop.
• Excellent mechanical properties: The valve rod in a butterfly valve is designed as a through rod structure. After tempering, it offers excellent mechanical properties, corrosion resistance, and scratch resistance. During operation, the valve rod rotates without lifting, reducing wear on the packing and ensuring reliable sealing.

Where are butterfly valves used

• Chemical industry: Used for on/off and modulating control of chemicals and liquids in processing and transportation.
• Oil and gas industry: Employed for isolation and regulation in pipelines and vessels.
• Water treatment: Utilized to control the flow of water and treatment chemicals, particularly in seawater and raw water management.
• HVAC systems: Essential for controlling flow rates and regulating air and fluid flow. Typically used in large duct systems to manage airflow, in chilled water systems to prevent cooling water flow, and in heating systems to regulate hot water flow.
• Food and beverage processing: Used to manage fluid flow during processing, ensuring sanitary conditions.
• Potable water: Water distribution systems are ideal for handling large fluid flows in pumping stations, water collection, transmission, and drinking water distribution and serve as flow isolation devices.

Disadvantages

• Limitations for high-pressure and high-temperature systems: Butterfly valves are generally unsuitable for very high-pressure/temperature applications, as they may be prone to leakage due to the design of the disc and seal.
  • Exception:  High-performance butterfly valves are constructed with more robust materials; they have increased temperature and pressure ratings, enhanced corrosion resistance, and improved sealing capabilities.
• Precise flow control: While they can be used for basic flow regulation, butterfly valves are not ideal for applications requiring precise flow control, as their design does not allow fine adjustments. They are commonly used when flow regulation is needed, and leakage isn't critical.
  • Triple offset butterfly valves offer enhanced sealing for applications where leakage is a concern, making them suitable for flow regulation and leak tightness. However, their flow control precision is generally less than that of valves like globe valves, which are designed for fine adjustments.
• Flow obstruction: The disc remains in the flow path even when fully open (as the disc is centrally mounted), which can cause a pressure drop and make it unsuitable for applications where minimal flow resistance is critical.
• Not piggable: Butterfly valves are unsuitable for systems requiring pigging (cleaning with a device that travels through the pipeline) because the disc obstructs the flow path.

Butterfly valves vs ball valves, gate valves, and globe valves

Butterfly valves are used for quick on/off applications and in low-pressure systems where cost and space efficiency are priorities. Other valve types, such as ball, gate, and globe valves, have unique features and are suited for different applications.

Table 1: Butterfly valve vs other valve types

Criteria	Butterfly valve	Ball valve	Gate valve	Globe valve
Operation	Quarter-turn	Quarter-turn	Multi-turn	Multi-turn
Flow control	Good for on/off and throttling	Excellent for on/off, not ideal for throttling	Good for on/off, but not ideal for throttling	Excellent for throttling and flow regulation
Pressure drop	Low	Very low	Low	Moderate to high
Space requirement	Compact	Compact	Requires more space	Requires more space
Cost & maintenance	Generally low, low maintenance	Moderate to high cost, low to moderate maintenance	Moderate cost, moderate maintenance	Moderate to high cost, moderate to high maintenance
Media suitability	Suitable for slurry and viscous media	Not suitable for slurry, suitable for viscous media	Suitable for slurry and viscous media	Not suitable for slurry, not ideal for viscous media
Leakage	Moderate (depends on seat design)	Very low (tight shut-off)	Low	Moderate

For more information on comparing a butterfly valve with other valve types, read our butterfly valve vs ball valve and gate valve vs butterfly valve articles.

FAQs

What does a butterfly valve do?

A butterfly valve regulates fluid flow through a pipe by rotating a disc to open, close, or partially obstruct the passage.

Can a butterfly valve be used for flow control?

Yes, a butterfly valve can be used for flow control. However, it may not provide as precise control as other types of valves, such as globe valves, especially at low flow rates.

When to use a butterfly valve vs a ball valve?

Use a butterfly valve for applications with slurry or viscous media with controlled flow and a ball valve for applications needing tight shut-off and minimal leakage with quick on/off control.

What is the difference between a butterfly valve and a gate valve?

A butterfly valve uses a rotating disc for flow control, while a gate valve uses a sliding gate to open or close the flow path.