Butterfly valves are one of the most common types of valves used to regulate or isolate liquids and gases. It controls the fluids and gases by opening and closing a 90-degree rotatory (quarter-turn valve) metal disc. 

The disc helps to stop or start the flow manually or automatically. Due to its slightly weighted and compact design, it is used in domestic, commercial, and industrial applications.

The butterfly valves are of various types depending upon their pressure-handling capabilities and design.

In this article, you will get the best idea about the types of butterfly valves and their applications.

Butterfly Valves Actuation Method

The butterfly valve needs to operate externally, either manually, automatically, or using electricity. The outer source that operates the butterfly valve is called the valve actuator. The actuators can run by electricity, hydraulic pressure, or compressed air. There are different types of valve actuators available, and choosing the right one depends on several factors, such as the frequency of opening and closing the disc, valve size, pressure, and more.

Let’s understand each method one by one.

1. Manual Actuation Method

The manual actuation method is a simple way to open or close a butterfly valve using hand-operated force. It involves a handle lever, which can be oval or circular in shape for small-sized valves. 

Gears are used for some large valves, including a piston indicator that helps you locate the disc position. When you rotate this handle lever, it moves the valve’s disc, allowing the valve to either open or close.

This is the easiest and most basic way to control a butterfly valve. No motor or automation is needed, which makes it cost-efficient, requiring only manual effort to operate it.

2. Automatic Actuation Method

The automatic actuation method is simpler to use and is used to operate the larger-sized butterfly valves. The actuator automatically opens and closes the valves to control the flow of water, air, or gas in a pipe. 

The actuator (which can be electric, pneumatic, or hydraulic) moves the valve when you press a button or send a signal from a control system. They run on electricity, compressed air, or hydraulic pressure, and the best part is that you can operate them from a remote location. 

In any case of actuator failure, if the valve remains open or is not open after closing, then the valve can operate manually.

Types Of Butterfly Valves

1. Zero Offset Butterfly Valve

Zero-offset butterfly valves, or concentric valves, are one of the simplest types of butterfly valves. In these valves, the stem passes through the centerline of the disk. When the stem rotates by an external medium (manually or by actuators), it causes the disc to rotate around the central axis. 

When the valve is fully opened, the flow is divided into two parts through the disc, allowing the fluid or gas to pass through while keeping the valve body from coming into contact with the flow, helping to protect the valve from corrosion.

Zero Offset Valves are highly affected by friction, so the soft seats of the valve need to be changed quickly or be maintained regularly. It is commonly used in pipeline systems of fluids or gases.

Applications

• Used in chemical industries to control the flow of chemical fluids.
• Used in food industries to control the flow of liquids and gases.
• Used in the water treatment process to regulate the water.
• Used in the power generation process to control the fluids and steam.
• Used in HVAC to regulate the air and gases.

2. Double Offset Butterfly Valve

Double offset or eccentric butterfly valves are used to offset the stem. Here, the stem axis is offset twice. The first offset is behind the centerline of the seat, and the second is the vertical centerline of the valves. This method lifts the disc off the seat as it opens, reducing friction and making the valve easier to operate.

It also has soft seats, which are more compatible with high pressure and temperature than zero-offset butterfly valves.

Applications

• Used in the oil and gas industries to regulate the fluid during processing.
• Used in the power generation process to control steam and other liquids.
• Used in a chemical process to handle various chemicals and other fluids.
• In the mining process 
• Used in the water filtration process to regulate the water flow.

3. Triple Offset Butterfly Valve

The triple-offset butterfly valve has an extra angular offset added to the body’s ceiling cone. The additional offset avoids the seat’s contact with the disc, which only occurs when the disc is completely closed.

This method helps reduce wear and tear. The seats in triple-offset butterfly valves are made of hard metals, making them more durable than soft seats.

These hard metal seats are compatible with high pressure and temperature and prevent leakage.

Applications

• In thermal fluid plants, the seat is compatible with high pressure and temperature.
• Used in oxygen plants to remove water from the air.
• In vacuum services and piping systems.
• In hydrocarbon processing industries.

4. Smart Centralized Wireless Valve Controller (Flotaa)

The Smart Centralized Wireless Valve Controller is an automated butterfly valve controller with an actuator and a smart controller. You can control this valve remotely via a web application. It is an IoT-enabled, Wi-Fi-operated butterfly valve that can operate manually and automatically.

Additionally, it contains an IP67-enclosed actuator unit and an LED for status monitoring. A 220-volt AC electric supply is needed to operate.

A smart centralized wireless valve controller is a versatile valve that is used in many applications at low to high pressure and temperature.

Applications

• Used in water treatment plants to regulate the water flow.
• Used in manufacturing industries to provide real-time data on the regulation of fluids. 
• Used in power stations to ensure the smooth flow of fluid and cooling liquid and to prevent hazards.

Conclusion

Butterfly valves are the best valves to handle pressure and flow rate quickly. For all applications, it is the best option to regulate the fluid. If you are searching for the best butterfly valve, you need to consult with an expert to determine the best one for your application.

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