Everything You Need To Know About Butterfly Valves

Aug 3, 2023 | News

Butterfly valves are a common type of valve used in a variety of applications and industrial processes. They feature a simple yet effective design that provides easy open-close operation and excellent flow control. This blog post will cover the key things to know about butterfly valves, including:

• What is a butterfly valve and how does it work?
• Different types of butterfly valves
• Common applications
• Key features to consider when purchasing
• Tips for proper installation and usage

large size double flange butterfly valve

What is a Butterfly Valve?

A butterfly valve consists of a circular disc (known as the “disc” or “butterfly”) that rotates within the valve body to either allow fluid to pass or block flow. As the disc turns, it moves from a parallel position (fully open) to a perpendicular position (fully closed).

This creates a very simple and versatile valve suitable for a wide range of applications. Some key advantages of butterfly valves include:

• Simple and robust design
• Low maintenance
• Wide selection of sizes and pressure ratings
• Compact size
• Relatively inexpensive
• Easy open-close operation

Types Of Butterfly Valves

There are several common types of butterfly valves based on installation, connection types and material composition:

• Lug type – Features mounting lugs on the valve body for attachment to mating flanges or brackets.
• Wafer type – Sit between two mating flanges and do not have their own end connections.
Double flange butterfly valve – Have a flange connection on both sides to install in-line between pipe sections.
• Single flanged – Have a flange connection on one side and another end connection type on the other side.
• Grooved end – Utilize grooved connections rather than flanges for installation.
• Resilient seated – Have an elastomer seal attached to the disc edge for a better shut-off.
• High-performance – Feature a metal-to-metal or balanced stem seal design for maximum efficiency.
LT butterfly valves – are designed to operate in lower temperature applications.

Common Applications For Butterfly Valves

Some of the most common applications for butterfly valves include:

• Water and wastewater transmission – Large diameter butterfly valves are often utilized in water pipes and mains.
• Power plants – Used in circulating water, condenser water and steam systems.
• Oil and gas pipelines – Double-flanged valves are ideal for in-line installation in pipelines.
• Pulp and paper processing – Found in digesters, stock lines, white and black liquor systems.
• Marine applications – Saltwater-resistant valves withstand conditions on boats and ships.
• Chemical processing – Chemical-compatible valves are utilized throughout chemical plants.
• HVAC systems – Butterfly valves regulate air and water flow in commercial and industrial HVAC.

Key Features To Consider

When purchasing butterfly valves, be sure to confirm the following:

• Pressure rating – Suitable for the maximum pressure of your system or process. Higher ratings mean wider safety margins.
• Temperature rating – Rated for the full temperature range of your application. Most standard butterfly valves operate from -100°F to 300°F.
• Disc material – Common options include stainless steel, aluminum-bronze, ductile iron, etc. Choose based on your media compatibility needs.
• Seat material – Rubber, Teflon, and other elastomers provide resistant sealing for different fluids.
• Actuator – Electric, pneumatic or manual depending on your preferred open-close mechanism.
• Connection type – Flanges, threads or grooves that match your existing pipes.
GGG50 butterfly valve – If replacing an existing butterfly valve, ensure the new one has the same dimensions.
• Certification – Valves certified for particular industries have passed stringent safety and performance testing.

Proper Installation And Usage

Some tips for working with butterfly valves:

• Ensure proper alignment of the valve within the pipeline to avoid stresses on valve body.
• Lubricate the stem, bearings and seating surfaces according to manufacturer’s guidelines.
• Gradually open and close the valve to allow the fluid to pass smoothly and avoid pressure spikes.
• Exercise the valve periodically if it remains inactive for long periods. This keeps seals and O-rings from sticking.
• Clear debris from valve and actuator before operation.
• Replace seals, gaskets, bearings and O-rings regularly according to maintenance schedule.