What are the types of butterfly valves?

Butterfly Valve is one of the circular motion valves. The types of butterfly valves are different based on how they are classified. It is from the family of quarter-turn valves (90˚ angle), used to regulate the flow of fluids only. It is easy to use because its rotation when it is at an angle of 90˚ will change the valve position from fully closed to fully open. As for the butterfly valves that are large in size, they are operated by circular handles, and the diameter of the disc is the diameter of the pipe.

Advantages of the butterfly valve

• Its price is relatively low.
• The closing element is a rotating disc.
• Commonly used with on/off operations.
• It can be used in throttling cases.
• It is used to secure various operations against fires.
• It is used in low-pressure applications.
• Most butterfly valves are equipped with soft seats so that they have an excellent seal.

Types of butterfly valves based on the type of seat:

• Butterfly valve with a flexible seat.
• Butterfly valves with a hard seat.

Article on: The difference between a Soft seated butterfly valve and a Metal seated butterfly valve

Types of butterfly valves based on the type of lining:

There are 3 types of butterfly valves, which are:

Rubber-lined butterfly valve

The advantages of this type are that it is low-cost, can be used for low-temperature applications, and does not require skill.

Plastic-lined valve

This type is characterized by being used with harsh chemicals, ultra-pure applications, sanitary applications, or abrasives, and the insulation cavity itself is lined with plastic.

Metal-lined valve

This type is characterized by being used for high-pressure and high-temperature applications, or those applications that require fire protection.

It can be of single offset, double offset, or triple offset type

Butterfly Valve Types by Shape

There are 4 types of butterfly valves, which are:

Wafer Butterfly Valve

Wafer butterfly valves are typically used in low-pressure applications, and are often used in conjunction with other valves, such as ball valves or gate valves.

The Wafer butterfly valves feature thin bodies. This makes them ideal for installation in applications where space is limited. Wafer butterfly valves are also typically made of stainless steel or other corrosion-resistant materials. This makes them suitable for use in applications where the fluid is corrosive.

Wafer butterfly valves are typically operated by a hand wheel or air motor. The hand wheel is used to rotate the disc, which opens or closes the valve. The air motor is used to rotate the disc automatically.

Wafer Butterfly Valve Features:

• Features two or more central openings to aid in installation.
• Lightweight and inexpensive.
• The valve body is fixed between two pipe flanges, so it cannot be used as a pipe end.
• The bolts bear all the stresses generated by the pipes.
• You need skill and experience when installing, as they must be centered between the pipe flanges.

Video showing what a wafer butterfly valve looks like

Lug butterfly valve

LUG butterfly valve for all types of fluids. The wrought iron LUG butterfly valves are assembled above ground to solve congestion problems and are installed using two bolts (without nuts). They can be adapted to all types of fluids and restrictions, and like the WAFER butterfly valves, the LUG butterfly valves have two friction points. This gate valve is used to disassemble one side of the assembly while keeping the other side under pressure and in full operation.

Advantages of the lug butterfly valve:

• It has bolt holes for connecting pipe flanges.
• It can be used as pipe ends.
• The body materials are of low strength, as the threads of the Lug valve are weak, so the Lug valve has less torque force than the Wafer valve.
• Since there are threaded bolts around the entire area, the Lug valve is a safer option.
• Most customers can switch from a Wafer to a Lug valve, but they cannot switch from a Lug to a Wafer.

Flanged Butterfly Valve

Flanged Butterfly Valve Features:

• The valve has a flange on both sides.
• Common with large-size valves.
• Welded Butterfly Valve
• They were used for very high-pressure applications.
• Since most plastic-lined valves are limited to PN10/16 (150#) flanges, this type is rarely seen with plastic-lined valves.

Butterfly Valve Materials

• Cast Iron.
• Carbon Steel.
• Stainless Steel.

Application Where Butterfly Valves Are Used:

• Homes.
• Offices.
• Hospitals.
• Manufacturing Plants.
• Oil Refineries and Oil Rigs.
• Power Plants.
• Water Treatment Plants.
• Gas Works.

Butterfly Valve Idea

A butterfly valve is a valve with a circular body and a rotating disc in the middle connected to a stem (metal rod). Rotating the stem causes the disc to rotate. Several methods are used to rotate the stem. For small diameters, a regular circular hand or a pressure handle is used, while for larger diameters, actuators of various types are used, whether electric, air, or water. In both cases, a gearbox can be installed to facilitate the rotation of the disc.

This video will help you understand how a butterfly valve works

It shows the direction of the flow of fluid when the valve is closed. The flow stops completely when the disc seal on the seat presses against the inner diameter of the valve body. Most valves are soft-sealed in a flexible material against which the disc seals. If the butterfly valve is designed for severe conditions, it consists of two metal sealing rings, one on the seal and one on the sealing seat.

The stem does not have airtight seals (it can be a stuffing box with some packing glands or O-ring seals), to avoid leaks that contaminate the working fluid or prevent the fluid from corroding the internal mechanical parts of the valve.

Summary:

Butterfly valves are not linear valves, meaning that the flow through the valve does not change linearly with the opening angle. The resistance of these valves is relatively small when fully open, while they become more sensitive to flow control when the opening angle becomes between 15 degrees and 70 degrees.

These valves are naturally accompanied by diagrams and charts, and there are also approximate mathematical relationships to show these properties.

Where to find the best types of butterfly valves

At CareWater, we provide all types of valves that different applications need. Here you will find a summary of each type of valve. You can contact us for more specifications and uses. Our organization is proud of its leading role in supplying all types of high-quality valves, which meet the needs of various industrial and commercial sectors. We are committed to providing innovative and advanced products that ensure the highest levels of performance and safety. Our company relies on the latest technologies and international standards in the manufacture and supply of valves, making us the ideal choice for companies looking for quality and reliability.

Through our highly experienced and specialized team, we are keen to provide comprehensive technical support and after-sales services to ensure our customers’ complete satisfaction. Our products are distinguished by their diversity and ability to withstand harsh operating conditions, making them the ideal choice for various applications. Our commitment to quality and efficiency is reflected in every aspect of our work, reinforcing our position as a trusted partner for customers throughout the Kingdom and beyond.