Butterfly valve types
What are butterfly valves?
Butterfly valves belong to the rotational motion quarter turn valves and they are used mostly to regulate, stop and to start the flow. The word butterfly in the butterfly valve is defined as a disk that is connected to the rod. When this rod is rotated the disc rotates itself at 90 degrees and the butterfly valve closes and opens.
Butterfly valves are very popular in the industry because of their fast operation, lightweight and its low cost. These valves use automatic gears, handles, and other actuators for operation as per the requirements.
Butterfly valves types
Butterfly valves are very important in applications where tight shutting off is required. The disc closes and opens with a low torque and the rotation of 90 degrees and it works for all kinds of compatible applications. They desire to cost very less and they are very light in weight so they are preferred more over other types of valves.
Types of butterfly valves based on body structure
Butterfly valves are available in the following types based on the body structure:
1. Wafer type
This wafer type butterfly valve is very easy to install and it is placed between pipe flanges surrounding the valve body.
2. Lug type
This lug type has protruding lugs that are used in butterfly valves and it provides the passage that matches the flanges.
3. But welded type
These types of valve ends are used in high pressure services and it is directly welded with the pipe in the butterfly valves.
Other types of butterfly valves
Butterfly valves are mostly distinguished by below types of valves:
1. Zero butterfly valve
This zero butterfly valve is designed to solve all the tightening problems that take place between the seat and the disc of the butterfly valve.
The disc and the stem of this valve are situated in the center and it helps in creating the seal when the disc deforms the seat and it helps in causing friction during the whole cycle. These valves can handle coatings, solids, chemicals, food and other applications.
2. Double butterfly valve
The double butterfly valve structure features the stem center. With this structure the disc valve is able to leave the valve seat immediately and it helps in reducing unnecessary over compressions and scrapings between them.
These valves also help in decreasing prolong and the wearing process life of the valve. The seats of these valves are made from metals which expands the application range of butterfly valves to high temperature applications.
3. Triple butterfly valve
The triple butterfly valve eliminates the rubbing between the seal ring and the seat through the path and it helps in reducing the cycle life.
They are used in the apps that are very similar to the gate valves where a metal seat is used but triple butterfly valves can close and open quickly and it can operate frequently even if there are emergency shut offs. These valves are used for both low and high temperatures and have a very low torque.