What Is Wafer Butterfly Valve | Dombor

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.

• Tallo

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.

• Disk

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.

• Asento 

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.

• Gear

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.