Concentric Vs Eccentric Butterfly Valve

Valves are an essential part that is used in the industrial applications. They control the flow of liquid from one container to another. Valves also assist in starting or stopping the flow of any liquid. Both concentric and eccentric butterfly valves are quite popular in the valve industry.

A valve needs to function properly so there are no leaks and control the flow of liquid properly. There are numerous valves available in the market. The valves discussed in this article are eccentric butterfly valves and concentric butterfly valves. Both of these valves are very different from each other. In this article, we will explain what a concentric and eccentric butterfly valve is and what the difference between a concentric vs eccentric butterfly valve.

What Is A Concentric Butterfly Valve?

The concentric butterfly valve controls the flow medium that uses a rotary disk. The disk valve has a disk in the passage. However, it is very thin; therefore, the resistance it gives is very less. Butterfly valves have various advantages like economic construction that consists of lesser components, making them very easy to maintain and operate. The relatively lightweight and wafer design body reduces installation costs, pipe support, setup time, and labor. 

One of the most common butterfly valve arrangements is a concentric butterfly valve or centric butterfly valve. Concentric butterfly valves have a stem that travels along the centerline of the disk. This configuration is also called a resilient seated valve. 

What Is An Eccentric Butterfly Valve?

An eccentric valve is an industrial valve designed to close or completely open a passage of the medium flowing via a pipe. Eccentric butterfly valves are also used for controlling the flow. The only drawback of this type of valve is that its complete tightness can’t be guaranteed for long-term usage. 

Concentric Vs Eccentric Butterfly Valve 

Knowing the difference between a butterfly valve concentric and eccentric. Selecting the wrong kind of valve can disrupt the entire operation. Several types of valves are available in the market, including concentric and eccentric butterfly valves. Both these valves not only look very different but are internally different as well.

• An eccentric butterfly valve disc is combined with a seal retaining ring, disc seal, and retaining bolt. On the other hand, the centerline butterfly valve is merely a normal disc. 
• The sealing of the eccentric butterfly valve has an extra laminated disc seal that is connected with a meat body seat. On the other hand, the centerline butterfly valve has a very simple sealing where the disc directly touches the rubber seat.
• A centerline butterfly valve is a soft seal that can be a replaceable welded seat or an integral body seat, while the eccentric butterfly valve is a meat seat. 
• Since both these valves are very different in terms of design, the rubber seal of the centerline butterfly valve cannot bear the high temperature. However, the butterfly valve can also work well with a hard seal design. 
• A butterfly valve’s maximum temperature can reach 150LB/PN25 pressure. On the other hand, Eccentric butterfly valves can reach a pressure of 600LB/PN100. 

Advantages Of A Concentric Butterfly Valve

The following are the advantages of concentric butterfly valves –

• One of the best things about concentric butterfly valves is that it uses a neutral seal structure. 
• The lower and upper end of the disc close to the valve stem are two very smooth flat surfaces situated close to the rubber seat ring. This prevents the medium from leaking.
• While the valves are closed, the disc gradually compresses while rotating. This causes the seat ring to deform elastically. 

Disadvantages Of Concentric Butterfly Valves

The following are the disadvantages of concentric butterfly valves –

• One of the major disadvantages of using a concentric butterfly valve is that it could only be made into a soft seal butterfly valve due to its structural characteristics. 
• These valves can be used only in normal and low-pressure conditions and are unsuitable for high pressure and high-temperature working conditions. 

Advantages Of An Eccentric Butterfly Valve

The following are the advantages of eccentric butterfly valves –

• An eccentric butterfly valve uses hard metal sealing, an advanced valve technology. In this case, the valve seat and body are connected, and the seat sealing surface of the valve is layered with anti-corrosion and heat-resistant alloy steel. 
• These valves can work in high-temperature conditions and have quick operation and quick and frictionless closing and opening. 

Disadvantages Of An Eccentric Butterfly Valve

The following are the disadvantages of eccentric butterfly valves –

• When the valve plate is regularly opened, the medium generates positive erosion on the sealing surface due to the multi-layered soft and hard stacked sealing ring mounted on it. The sealing effectiveness would be immediately damaged if the soft sealing ring washed off into the metal plate interlayer.

• This butterfly valve seat construction is not optimal for valves with a diameter less than DN200 due to structural constraints, since the overall form of the valve plate is thicker and has a greater flow resistance. In the idea of the triple eccentric butterfly valve construction, the torque of the transfer mechanism forces the valve plate towards the valve seat, and a seal occurs between the plate’s sealing surface and the valve seat. 

• The seal leaks when the flow medium is reversed because the unit positive pressure between the valve plate and the seat is less than the system pressure.

Why Choose Industrial Bytterfly Valves From Dombor?

You can buy industrial butterfly valves from everywhere; however, none can ignore Dombor when buying butterfly valves. Dombor is a renowned manufacturer of industrial valves. Their products are of superior quality. Here are some of the best features of Dombor that make it different from other companies in the market.

● Dombor offers easy-to-use construction of the valves that require little to no workforce. It is also important to note that whenever someone buys valves from Dombor, they’ll never have to deal with the problem of controlling operations. 

● Their designs are very flexible, and their products, i.e., valves, adjust to the various industry needs and applications.

● Buyers will get an uninterrupted flow of liquid. Valves present don’t offer any major obstructions that disrupt the operation. 

● The butterfly valves of Dombor are automated for easy operations.

● The valves, especially butterfly valves, are very lightweight as they have a thin dimension and are very easy to install.

Conclusion

Both concentric and eccentric butterfly valves have their advantages and disadvantages. Ultimately, the buyer should choose the valve depending on several factors. One has to pick the valve that is well suited for their requirements and needs. A concentric butterfly valve is good for normal working conditions. In contrast, eccentric butterfly valves are best if the working conditions get extreme, that is, when there is high pressure and temperature. Please contact us to buy high quality industrial butterfly valves from a reputed provider.