The wafer-style butterfly valve often just has two or four non-threaded holes to hold it in place and align it with two flanges that are mated. When using a wafer valve, a lengthy bolt or threaded rod that goes straight through the valve’s two flanges is employed. By pulling the flanges together, the valve is held in place. The purpose of a wafer butterfly valve is to maintain a seal to guard against double-directional pressure differential in liquid flow.
To prevent any backflow in systems that were made for unidirectional flow, the wafer form of butterfly valves was developed to maintain a tight seal and protect against bi-directional pressure differential. It is achieved by utilizing a strictly fitted seal, like a gasket, an O-ring, precision machined as well as a valve face on the upstream and downstream valve sections.
The majority of wafer-style butterfly valve collections are designed with four holes that line up with the pipeline they are linked to. The valve is made to fit snugly between two pipe flanges. The majority of wafer butterfly valves are compatible with most flange standards. The seal between the valve and flange connection is incredibly strong, thanks to the rubber or EPDM valve seat.
Wafer butterfly valves cannot be utilized as pipe ends or end-of-line services, in contrast to lug butterfly valves. If any side of the valve needs maintenance, the whole line needs to be closed. Butterfly valves in the wafer form are produced to work with either electric or pneumatic actuation. Depending on the application and the flow media, the disc and seat materials should be chosen.
Parts Of A Wafer Butterfly Valve
The wafer-type butterfly valve has a minimal part count and is distinguished by its straightforward design, compact size, and low weight. Here are the main components of wafer butterfly valves everyone should be aware of:
- Valve Body
The bodies of butterfly valves typically slide between two pipe flanges. There are no lugs that stick out from the wafer body. The pipe flanges and the wafer valve are sandwiched together, and the body is encircled by the flange bolts. Compared to the lug-style butterfly valves, the wafer style is more affordable. Wafer designs prevent the weight of the pipe system from passing through the valve body directly.
The butterfly valve’s stem can have a one-piece shaft or two-piece construction. In most resilient seated designs, the stem is shielded from the media, permitting for an effective material choice in terms of price and mechanical attributes.
According to the stem’s level of protection, there are two different designs: wetted or non-wetted. Stems that are not wet are guarded against any corrosive or erosive media that might be present in the line. Wetted stems need to be manufactured of a material compatible with the media running through the line because they are not safeguarded against these.
A disc inside the industrial wafer butterfly valves regulates the flow of media via the valve. The concentric or eccentric disc can be used for the valve. The concentric disc is the less complicated among these two. The stem in the concentric design cuts through the disk’s centerline. Low-pressure applications frequently employ concentric valves.
Nonetheless, the stem of the eccentric disc design goes at the back of the center line, in the contrasting direction of the flow. The eccentric disc was initially intended to help deter connection between the disc and seal. Later, it was entirely closed, hence extending and enhancing valve life.
Different elastomers or polymers are utilized to create a butterfly valve’s seat, which is bonded to the body, squeezed, or locked up. Along the inner diameter of the valve, the seat is located. The flow is stopped when the disc presses against the seat and they seal. In the original design of these valves, the metal disc rested on the metal body, which did not produce a secure, leak-free seal. The inclusion of elastomers or polymers in the valve design will assist in providing a leak-proof and tight seal.
- Hand Lever
Typically made of steel, these components undergo chemical treatment, powder coating, and salt spray testing to ensure dimensional precision. A handle and a locking lever are frequently found on hand levers. Additionally, they are typically employed for tiny valves. The sealed, open, and partly open states of these hand levers can all be secured.
The gear is yet another component on the list of wafer butterfly valve parts for manually operated ones. For larger butterfly valves, these parts are employed. Utilizing a gearbox boosts the torque but reduces the pace of opening and shutting down. The gear-based wafer butterfly valves are self-locking and irreversible. However, they might retain positional cues.
How Does Wafer Butterfly Valve Work
Similar to other quarter-turn valves, wafer butterfly valves function, and there are several parts that make up this valve. The metal disc is the most crucial. The butterfly is the common name for this metal disc. When the valve is closed, the butterfly, which is positioned on a rod, prevents liquid flow.
The metal disc or butterfly turns a quarter turn once the valve is fully open. The route is open and permits the free circulation of liquids or air. How the valve is opened or closed, whether partially or completely, will determine how the disc moves.
If the valve is just partially open, the disc would not revolve through a full quarter revolution and might not enable unhindered passage. Slight volumes of liquids or air will therefore flow through. The disc will rotate 90 degrees if the valve is completely opened, allowing greater volumes of fluid or air to flow through.
The butterfly wafer valve is made up of a lot of additional parts. They consist of the body, seal, packing, stem, actuator, and resilient seat. To create the ideal seal, the robust seat is positioned on the valve’s body. In the event that the robust seat is harmed, the packing offers an extra seal.
There are various configurations for industrial butterfly valves. Based on the method, some operate manually while others do it electronically. They come in various styles as well, which can be acquired from an industrial valve supplier. There are some that offer excellent performance in front suctions and huge pump lines.
Pros And Cons Of Wafer Butterfly Valves
Advantages Of Wafer Butterfly Valves
Here are the main advantages of butterfly wafer valves:
- The flowing medium can travel through a stream-lined butterfly disc without experiencing a significant pressure reduction or flow restriction.
- Butterfly wafer valves are quick-acting; to switch the valve from the completely open to the entirely closed position, the stem only needs to be moved 90 degrees (1/4 turn).
- The butterfly wafer valve design is well adapted for flow regulation and does not produce much turbulent flow when somewhat opened or shut down.
- The butterfly wafer valves are better appropriate for larger applications since they are often less expensive and not heavier.
Disadvantages Of Wafer Butterfly Valves
Here are the main disadvantages of butterfly wafer valves:
- When fully opened, these valves have a modest pressure drop.
- Butterfly wafer valves are typically changed completely and then overhauled in a workshop rather than being maintained on-site.
- Pigs, which are tools used to clean and examine the interior surface of piping, cannot be inserted into butterfly valves.
What Is A Wafer Butterfly Valve Used For?
Butterfly wafer valves are used in home pipes, firefighting equipment, and ships. These valves are commonly employed in the cooling water system for thermal power plants in addition to other general industries, including petroleum, chemical, gas, and water treatment. Butterfly wafer valves are also appropriate for pressurized applications involving air or gas.
These valves are used in large capacity lines like the forward and aft sea water suction lines on ships. Butterfly wafer valves are useful in a broad variety of other applications and work particularly well with slurry and big volumes of water. Here are the most common sectors that utilize wafer butterfly valves for industrial processes:
- Aerospace sectors
- Compressed air applications
- Corrosive processing
- District heating, mining, and shipyards
- Gas application
- HVAC systems
- High-pressure and high-temperature water and steam services
- Irrigation and agricultural needs
- Petroleum Industries
- Refrigeration and Air Conditioning systems
- Slurry application
- Sanitary valve applications
- Sprinkler and fire protection systems
- Vacuum services
- Wastewater treatment
The primary use of wafer butterfly valves is to halt, begin, and regulate the flow. There are numerous applications for wafer butterfly valves. They function effectively in slurry and high-volume water applications. Talk to a trustworthy industrial valve manufacturer to get the best wafer butterfly valves for your business needs. If possible, you can get pre-order quotes and make negotiations at an affordable price.