A butterfly valve is a device that allows you to achieve better flow control. The design uses a metallic disc that rotates a quarter-turn at a time around a fixed-stem axis. The 90-degree turns provide quick-action control between open and closed positions. In addition, the disc is generally sized equally to the internal diameter of the adjoining pipe to give full-color capability.
Naturally, butterfly valves are manufactured in various sizes and design configurations to provide specific flow control functionality. As a result, varying applications and industries, including everything from HVAC and fire protection to slurries and sanitation.
So, when does it make sense to use a butterfly valve in your pump or vent system? Let’s take a look at butterfly valves’ advantages and disadvantages to help you make a more informed decision.
ADVANTAGES OF BUTTERFLY VALVES
Lightweight and Compact
Butterfly valves are great for several applications because they are very lightweight and provide reasonable flow control in a compact design. You will generally want to use a metal-seated valve for more extreme fluid processing, while a soft-seated butterfly valve is best for applications with low pressures and temperatures. The butterfly disc takes up little space but offers enough strength for most pump systems.
Simple and Cost Effective
Butterfly valves are very simple in design and have minimal maintenance requirements. They are easy to install and operate. Plus, they are typically much less expensive than a ball valve of the same size. They do not require much torque to operate effectively and can be automated for energy-efficient operation.
Quick and Efficient
The 90-degree turning radius allows for quick sealing upon actuation, which provides more accurate flow control with minimal effort to turn the valve on and off. Different butterfly valves are to consider, including zero-offset, double-offset, and triple-offset. The pressure will usually determine which type you need. The higher the offset, the more pressure the valve can handle.
Pressure Control
In addition to precision flow control, butterfly valves are excellent for pressure control. They experience minimal pressure drop during operation before the fluids recover energy quickly after leaving the valve. This keeps the pump system running efficiently with consistent fluid pressures.
DISADVANTAGES OF BUTTERFLY VALVES
Corrosion and Viscous Fluids
Viscous and corrosive fluids tend to scour against the discs of butterfly valves during operation, which can lead to rapid deterioration of the disc and loss of sealing pressure. If you are processing highly viscous liquids, you may want to consider a more robust ball valve or gate valve instead of a butterfly valve.
Cavitation and Choked Flow
When the valve is in an open position, it does not provide a complete port because of the disc. This can lead to excess debris accumulation around the valve in specific applications, cavitation concerns, or the possibility of choked flow. A ball valve may be a better solution if a full port is required.
No High-Pressure Throttling
A butterfly valve has an opening restricted between 30-80 degrees, making them efficient for low-pressure throttling applications. However, higher pressures may achieve better results with a globe valve. To learn more about butterfly valves from the leading valve manufacturers and determine if this is the correct solution for your application and pump system, contact DXP Pacific today. Let our pump experts help you find the right equipment to optimize your production.