Butterfly Valve Buyer’s Guide (2021 Update)

The butterfly valve is a popular and one of the most efficient and straightforward valves in the industry. It has only four main components: Disk, Body, Seat, Handle.

• Disk

Disk is the key part of the butterfly valve; it regulates, open and stop the flow of matter. The disk is connected to a rod that rotates when the handle or gear rotates by 90° or quarter-turn. The early use of the valve is to stop and open the flow, but someone sensed that it could also regulate the flow. So, now it is used in different industries and motor vehicles to control the flow.

• Body

Then we have the body; usually, the valve is encased in an average body, but the ball type has two types of bodies. The first one is lug type body; it has lugs that stick out as bolt holes. Lug types are expensive but allow the removal of downstream piping. The other one is wafer type; it doesn’t have any lugs. Instead, it is placed between two pipes. The wafer type cost less, but the design doesn’t transfer the weight directly to the pipe system.

•  Seat

The seat is a handy part of every valve. It sits between the body and the disc and provides ideal flow restriction. It can be bonded or locked in the valve and has different body materials like polymer and metals. The metal ones are for high-temperature applications.

• Handle

The handle is the part that makes the quarter turn to rotate the disk in the close or open state. It can be a handle, gear or an automatic actuator system.

There are several types of butterfly valves available in the market. Some of the most commonly used butterfly valve types are as follows.

• Actuated Butterfly Valve
• Double Flanged Butterfly Valve
• Double Offset Butterfly Valve
• Triple Offset Butterfly Valve
• Lug Type Butterfly Valve
• Wafer Type Butterfly Valve

Actuated Butterfly Valve

Actuated Butterfly valve control or stops the flow through a disk that rotates in diametrical axis inside the pipe. It allows 90° or quarter-turn movement in a small design.

Double Flanged Butterfly Valve

This type of butterfly valve creates an exceptional watertight seal even without the gasket. The hydrodynamic design to the disc minimizes the head loss to zero. It is widely used in water supply facilities, plumbing and irrigation to regulate and flow sectioning.

Double Offset Butterfly Valve

Double Offset Butterfly Valves are popularly known as high-performance valves. They have two offsets from the body center. The shaft axis is offset from the seat and body centerline; moreover, it is also eccentric to the valve’s centerline. The position of the disc creates a cam action when valves open and closes., this action produces friction in the first and last 10° of operation.

Triple Offset Butterfly Valve

It has three offsets; two applies to the location of the shaft in respect of bore and disc centerline, the third offset is the design in the axis of seat cone angle. Unlike double offset, triple ensures frictionless operation.

Lug Type Butterfly Valve

This type of valve has protruding threaded lugs to ensure solid bolt connection on the valve flanges. These valves are usually composed of malleable metal such as iron and steel. Typically, they are used in end-of-line services, and operation is compatible with pneumatic and electric actuation.

Wafer Type Butterfly Valve

Wafer Type Butterfly Valve has four holes that align to connect the pipelines. It is designed to clamp between two flanges of the pipes.

Butterfly valves are pretty popular and abundantly used in many different places. Like in motor vehicles, we can find a butterfly valve in the car carburettor. It also controls the flow of air to the engine.

They have wide usage in firefighter pipes due to their easy and rapid operation and adequate pressure. These properties also make them usable in corrosive and abrasive applications. We can also detect butterfly valves in oil, gas, pharmaceutical, power, chemical and marine industries.

Other popular application of butterfly valve includes.

• Cooling water, air and gases.
• Vacuum services.
• High pressure and temperature services.
• Compressed air and gas.

Moreover, they are also used in domestic pipelines.

These are some popular uses of butterfly valves; there are also many other usages depending on the type, size and quality of the butterfly valves.

Butterfly valves are quite popular in many industries. There are hundreds of manufacturers selling different types of butterfly valves of varying quality. Getting the right quality butterfly valve is crucial. So, here we shout out to some trustable manufacturers of butterfly valves.

DBV Valve

DBao is on the top of our list; they have plenty of experience and expertise to design and manufacture the perfect valves. Every type of butterfly is available in different materials and dimensions. Moreover, DBV can also create custom valves in custom materials, and the minimum order quantity is only one piece.

Features

• Wide-range of high-quality products
• No, minimum order.
• Custom valves on demand.

XHVAL

XHVAL is a Chinese based valve manufacturer building valves since 1986. They are API certified for the past 15 years. They have a variety of butterfly valves available in different materials and types. Moreover, they also offer customize valves as well.

Features

• Highly experienced.
• ASI certified.

Dezurik

Dezurik is an American valve manufacturer; they produce top of the line products and have a diverse history of high-quality products. They are popular for their knife gates moreover; they are also collaborating with APCO for better valve production.

Features

• Products can handle a wide variety of gases and liquids.
• All products are exceptional performers.

Bray Valves

Bray valve is a leading valve manufacturer in the western region; it has over 30 years of experience with happy customers in more than 40 countries. Bray has put their effort to bring innovation to butterfly valves, especially in electrical and pneumatic valve products.

Features

• Valves are excellent for chemical industries.
• Reliable and well-reputed brand in the western hemisphere.

NIBCO

NIBCO started in Elkhart, Indiana, and now it has ten manufacturing facilities in US, Mexico and Poland. They produce almost every type of valve and actuator; they were providing over 30000 varieties in 2018.

Features

• Wide variety of valves and actuators.
• Well-known for their high performing and quality products.

Here are the things to consider before choosing a butterfly valve.

Ease of Operation

Ease of operation is a crucial factor. Some people think the only operation is opening and closing of the valve, but it also includes ease of assembling and disassembling. Generally, the gate and globe valve take multiple turns to open and close while a quarter turns open and close the flow.

Fluid Properties

Every fluid has a different effect on every material, like corrosive chemicals can melt the seat and disc. So, it better to buy a valve with a full metal body to ensure long life. Moreover, other fluids have different effects on different materials. So, never forget to consider the properties.

Material

Material is another important factor because a low-quality material can withstand less temperature and pressure. Similarly, the fluids as described above have different effects.

Cost

Butterfly valves are typically cheaper than gate and globe valves. According to an estimate, they are 40% cheaper than the gate valve. Not only the retail but the installation cost is lower than other valves.

Maintenance

Maintenance cost is mandatory to consider. Sometimes the negligence can cause permanent damage, or over time; you might spend more on the maintenance than the valve’s cost. So, you must consider the maintenance cost to prevent yourself from extra cost.

Weight and Dimensions

You must consider the dimensions of the pipe and the weight that it can handle. Both are crucial factors because an oversize valve can cause leakage while an undersize valve will lower the flow rate. Also, a lightweight valve may break easily under high pressure, while a heavy valve can damage the pipes over time.

Type of Butterfly Valve

Type of butterfly valve, every type has its pros and cons. So, after considering the fluid properties, weight, maintenance, cost in short, every factor then moves to this point.

Common causes of Butterfly Valve Damage

Butterfly valves are used as shut off and regulating valves, so; it is necessary for them to restrict the flow in close conditions and ensure the flow when open. Moreover, it must prevent any leakage both inside and outside the valve. There can be many reasons for leakage, some of which are as follows.

• Valve’s seat gets covered in dirt, or the stem and disk are rusted.
• Damaged seat also causes leakage.
• Seal damage can cause leakage as well.
• Actuator improper functioning also causes leakage.

All the reasons as mentioned above cause leakage inside the valve. While these reasons cause leakage outside the valve.

• If the stem packing is worn out.
• Gasket damage between the valve body and bonnet.

There are different ways to repair various leakages. Below are some probable leakages and their solutions

If the leakage occurs between the actuator and valve, then the probable cause will be the leaked packing. So, to repair, you will clean the packing bone and replace it with the new one if necessary.

The valve is not closing and opening tightly. The main reason can be the stuck solenoid, less air pressure, pneumatic actuator may leak the air, or the limit switch is loose. It can be solved by replacing the solenoid or actuator. We can repair low air pressure by directly blowing the air in a pneumatic actuator.

If the seat seal is leaking, there can only be one reason for that debris between the seat seal. So firstly, clean the seat seal; if the valve continues to leak, then replace the seat seal.