Butterfly valves belong to the category of quarter-turn rotational motion valves. They are used primarily with the intention to start, stop or control the fluid flow. This particular valve got its name “butterfly” because of a disk that is attached to a rod.

When this rod of an industrial butterfly valve rotates the disk by 90 degrees, the valve performs the function of opening or closing. This type of valve is popular in many industrial applications because of its salient features such as lightweight, low costs and rapid operations.

As per the application requirement, the butterfly valves may need to use automatic actuators, gears and handles. Keep reading till the end to learn everything essential you need to know about this particular valve.

Butterfly Valve

Butterfly valves that are smaller in size generally are operated manually, on the other hand, the larger sized butterfly valves are usually motorized. For systems that have high flow capacities, the use of this particular valve successfully allows the use of smaller units that have reduced cost, weight and space requirement primarily.

The butterfly valve has a range of valve linings and two wetted parts that causes the valve to isolate the body from the media that is flowing which ultimately prevents the need for costlier sophisticated materials.

The smoothly contoured, cervice-free disc of the valve generated lower torques while the valve’s design makes them for easy installation, maintenance and service.

Uses of Butterfly Valves

The use of butterfly valves is expansive. Some of the typical butterfly valves applications are in the  wastewater treatment, water supply, fire protection, slurry services, vacuum services, energy generation, air and gas supply, marine systems,  lubrication systems, fuel handling systems, chemical and oil industries, pharmaceutical, food industry, compressed air and gas services, steam services and sanitary valve applications. Essentially, the butterfly valve is ideal for use in -  constant load applications, throttling valves and constraint space applications.

Main Components of Butterfly Valve

Basically. There are four main components of an industrial butterfly valve and they are -

1.    Butterfly Valve Body - The valve typically has a body that fits between two pipe flanges. The most common design of butterfly valve bodies is wafer or lug body design.

2.    Butterfly Valve Disk - The disk is the butterfly valve element that performs the function of stopping the flow. There are a variety of disk designs and orientation in order to boost sealing, flow and operational torque.

3.    Stem - The stem design of a butterfly valve either comprises one-piece or two-piece shafts. In most resilient seated designs, the stem of the valve is protected from the media, therefore, allowing the selection of an efficient material with respect to mechanical properties and cost.

4.    Seat - To deliver the shutoff operation, the seat of a butterfly valve uses an interference fit between the seat and the disk edge. The seat may be pressed, bonded or locked into the valve’s body.

Depending on different manufacturers, the seat is one particular component in a butterfly valve that can have different designs. Generally, a single-piece PTFE is a popular option that experts go for. The importance of a single-piece seat is that it has no metallic springs or O-rings for limiting the corrosive and temperature conditions that the PTFE seat can be exposed to. By applying the line pressure, the absolute cross-section of the seat is pressurized resulting in the seat to follow the naturally occurring deflections of the disc under pressure.

The Perks of Using Butterfly Valves

Now that we are aware of the basics of a butterfly valve, let us discuss the advantages that it has got to offer. They are - 

Fast to operate and Easy to open

Butterfly valve when rotated at 90 degree then it can provide complete closure or opening of the valve. A so-called gear box is also equipped with a butterfly valve in which the handwheel by gears is attached to the stem. This helps in significantly easing the valve’s operation but at the expense of its speed.

Relatively inexpensive to manufacture

The manufacturing of butterfly valves require less materials mainly due to their design. The most economical option being the wafer type that essentially fits between two pipeline flanges. Lug wafer design is another type that is held in between two flange pipes by the bolts that connect the two flanges and pass through the valve's outer casting. Moreover, the butterfly valves materials are often less expensive, therefore, making them a cheaper option to choose.

Requires reduced maintenance

Butterfly valves are known to offer reliable performance which also contributes to reduced maintenance requirement. They are less likely to suffer from wear allowing them to be useful for a longer term. This also helps in cutting down direct operating costs involved and significantly eliminates the hours of time needed for maintenance work.

Less space requirements

Adding to the list of advantages, the butterfly valves also have less space requirements. This is primarily due to their compact design which allows them to be perfectly installed in a space-restricted area in comparison to other valves available.

Varied Butterfly Valve Applications

As aforementioned, butterfly valves can be ideally used across a broad range of applications. They are enabled to perform efficiently in large volume water and slurry applications. The below enumerated are some of the common applications of a butterfly valve -

·         High pressure and temperature steam and water services

·         Slurry and related services

·         Cooling gasses, air, water, fire protection, etc.

·         Vacuum service

Gate Valve vs Butterfly Valve

Many users are confused when it comes to choosing between gate valve and butterfly valve. However, an industrial butterfly valve has certain advantages that makes them a popular choice over a gate valve. They are -

·         Easier installation and rapid operation than gate valves due to their lightweight construct and simple design.

·         Smaller face-to-face dimension in comparison to gate valves, therefore, making them an ideal choice application for small spaces.

·         Butterfly valves are more accessible as they have shorter shafts than gate valves.

·         Butterfly valves are an economical option as they require less expensive material for manufacturing and are also lighter in weight.

So, what are you waiting for? Choose the best supplier of industrial butterfly valves and make the most use of it.