If you're looking for a guide on choosing the suitable butterfly valve for your application, you've come to the right place. In this blog post, we'll cover all the basics of butterfly valves, including what they are, the different types available, and selection criteria to keep in mind. We'll also provide a step-by-step guide on installing a butterfly valve and troubleshooting tips in case you run into any problems.
Introduction
A butterfly valve is a quarter-turn valve widely used in various industrial applications. Butterfly valves are primarily used to control the flow of liquids and gasses. They are also used in some cases to regulate pressure.
Butterfly valves get their name from the fact that the disk that controls the flow of fluid through the valve resembles a butterfly. The disk is attached to a shaft connected to an actuator, and when the actuator is turned, the disk turns with it, opening or closing the valve as needed.
Many different types of butterfly valves are available. You need to know that choosing one from the many options on the market application can be a challenge. This article will provide an overview of butterfly valves and offer tips on selecting the right one for your needs.
How do butterfly valves work?
A butterfly valve is a quarter-turn valve used to control or isolate flow. Rotating disks serve as the closing mechanism on a shaft, so the name "butterfly" is derived from the shape of the disk. A butterfly valve is generally more cost-effective than a ball valve or other valves because they take up less space than globe valves. They are also suitable for applications where a significant flow rate must be achieved with a relatively small pressure drop.
Types of butterfly valves
There are three main types of butterfly valves: wafer, lug, and double-flanged.
Two retaining bolts attach a disc to the wafer butterfly valve stem. The valve's body has guide holes that align with bolt holes in the disc, allowing it to be installed between two pipe flanges.
Lug butterfly valves have a one-piece body with integral lugs that bolt the valve to the pipe flanges. The disc is attached to the stem, which passes through the valve's body.
Double flanged butterfly valves have a body with two integral flanges used to bolt the valve to the pipe flanges. The disc is attached to the stem, which passes through the valve's body.
Each type of butterfly valve has advantages and disadvantages, so selecting the style best suited for your particular application is essential.
Selection criteria for butterfly valves
When selecting a butterfly valve, several factors must be considered, such as the type of application, the operating conditions, the required flow rate, and the pressure drop.
The first step is to determine the type of application. Butterfly valves can be used for isolation or throttling applications. Isolation applications require that the valve be able to shut off the flow completely, while throttling applications only require the valve to regulate the flow.
The next step is to determine the operating conditions. This includes the temperature and pressure of the fluid, as well as the material compatibility. Butterfly valves are available in various materials, so selecting one compatible with the liquid is essential.
The third step is to determine the required flow rate. This will help you select a butterfly valve with the appropriate size and capacity for your application.
Finally, it would be best if you considered the pressure drop across the valve. Butterfly valves have a relatively low-pressure drop, but it is still essential to consider this factor when selecting a valve for your application.
How to install a butterfly valve
Installing a butterfly valve is a relatively simple process, but there are a few things to remember. The first step is to select the appropriate valve for your application. As mentioned earlier, there are three main types of butterfly valves: wafer, lug, and double flanged. Each class has advantages and disadvantages, so selecting the style best suited for your particular application is essential.
The next step is to prepare the installation site. This includes ensuring that the pipe flanges are clean and free of debris and that the bolts and gaskets are the correct size and type for the valve.
Once the installation site is prepared, the valve can be installed. The disc is attached to the stem with two retaining bolts for wafer butterfly valves and then installed between two pipe flanges. The disc is attached to the branch for lug butterfly valves, which passes through the valve's body and then bolts to the pipe flanges. Double flanged butterfly valves are similar to lug valves but have a body with two integral flanges used to escape the valve to the pipe flanges.
After the valve is installed, testing it to ensure it functions properly is essential. The most common way to test a butterfly valve is by performing a leak test. This can be done by pressurizing the system and checking for leaks around the valve body or stem.
How to troubleshoot butterfly valves
A butterfly valve manufacturer can sometimes cause trouble, even though they are relatively simple devices. The most common problems are leaks and sticking.
Several different things can cause leaks. The first thing to check is the seat. If the center is damaged or worn, it must be replaced. It is also possible for a leak to be caused by a loose disc. Make sure that the disc is tight on the stem. It may be necessary to take further action if the problem persists and replace the entire valve.
Sticking is usually caused by dirt or debris in the valve body. Cleaning the body with a brush or compressed air can often fix the problem. If the valve is still sticking, it may need to be replaced.