Guess from where the butterfly valve gets the term “butterfly”? It is actually a disk that is attached to the rod in the valve. Belonging to the family of quarter-turn rotational motion valves, these valves are mostly utilized to regulate, start and stop the flow of the liquid.
When the rod connected moves the disk by 90°, the butterfly valve closes or opens. So, why are butterfly valves popular? This is largely due to their low cost, lightweight and easy and fast application. Interestingly, the butterfly valves use gears, automatic actuators or handles for operation.
Components of a butterfly valve
Generally a butterfly valve has four main components namely the body, disk, seat and stem.
The valve body has two pipe flanges. Commonly found body designs is wafer and lug type butterfly valves.
The valve disk is the element that stops the flow. If you want to improve the flow or operate the torque, then altercations need to be made in the designs of the disk. In order to provide shutoff, the seat of a butterfly valve uses an interference fit between the seat and the disk edge. The seat may be locked into the body of the valve. The stem of the valve comprises one-piece or two-piece shaft design.
Types of butterfly valves
Belonging to a diverse family, there are various kinds of butterfly valves and interestingly each valve can be adapted to different temperatures and pressures.
– Wafer Type Butterfly Valve
– Lug Type Butterfly Valve
– Double Flange Butterfly Valve
– Concentric Butterfly Valve
– Eccentric Butterfly Valve
– Zero offset
– Double Offset
– Triple Offset
Wafer type butterfly valve
The most economical among the butterfly valves, a wafer style butterfly valve is crammed between two pipe flanges and the flange bolts surround the valve body. A wafer type butterfly valve offers sealing against two-directional differences in pressure in the fluid flow. This wafer version of the butterfly valve is designed in such a way that it will act as a shield against the two-way pressure difference.
These types of butterfly valves are easy to install. However, the wafer versions of butterfly valves cannot be used as an isolation valve.
Before we decipher the differences between wafer style butterfly valves and lug type butterfly valves, we should know what lug-style butterfly valves mean.
The lug type butterfly valves have two sets of bolts, which connect the pipe flanges to each side of the bolt inserted without nuts. The lug-style butterfly valves have threaded lugs outside the body of the valve.
Now, let’s debate on the differences between lug-style butterfly valves and wafer type butterfly valves.
If you want cost-effective butterfly valves, then go for wafer type butterfly valves because wafer style butterfly valves are less expensive than the lug-style butterfly valve.
The lug-style butterfly valves have the ability to carry the weight of the piping through the body of the valve. The wafer-style butterfly valve, however, cannot carry the weight of the piping system.
Wafer-style butterfly valves are not suitable for end-of-line services but lug-style butterfly is capable for end-of-line service.
Wafer-style butterfly valves are much lighter in weight when compared to lug type butterfly valves.
There are three main functions of butterfly valves:
– To regulate, control the flow smoothly
– Butterfly valves help in flow isolation
– Butterfly valves can be utilized to prevent backflow in certain situations.
Difference between butterfly valves and gate valves
When it comes to installation and handling of butterfly valves, they are quite easy. However, gate valves are quite difficult to install and handle. Butterfly valves are smaller in size and therefore, need much reduced space. However, given the large size of the gate valves, they need more space to be installed in the piping system. Since butterfly valves have shorter shafts, they are easily accessible. However, gate valves have longer shafts and are difficult to access.
Since butterfly valves came into existence in 1930, these valves have been multi-functional and have met the expectations of various industries, thanks to their diverse functionalities. Dubai-based Dutco Tennant LLC is the global leader in butterfly valves and all piping and plumbing needs.
Dutco Tennant LLC has gained a reputation over four decades in the plumbing, piping and firefighting systems of supplying the best valves in the Middle East and the GCC region. The wafer style butterfly valves supplied by Dutco Tennant LLC are useful in agriculture. Dutco Tennant LLC has the capability of supplying the best wafer type butterfly valves in various materials and for all applications across the regions.