Valves have been around the market for several years and are used for multiple applications in several industries. Further classified, these spare parts are devices to regulate the flow of the substance flowing inside the pipe attached to them. They start, stop and control the flow level and act as stimulants. Butterfly valves made their initial appearance around the 1930s and have been utilized by various industries since then as their major spare components.
These valves are named after their rotational function. They are quarter-turn valves and often open and close with a quarter movement of their control disk. When a butterfly valve is opened, the disk rotates to 1/4th capacity, allowing the liquid to pass through uninterrupted. Most often, the disk is parallel or perpendicular to the flow of the liquid, and these valves restrict the liquid from flowing once they are closed. They can regulate the flow by turning a little. Often made of cast iron, they can be further separated into various categories but are prominent in two types:
- Lugged Butterfly Valves
- Wafer Butterfly Valves
Understanding the difference between both types is essential for your knowledge of the valves, as a wrong valve placed wrongly can disrupt the process. Lugged vs. wafer butterfly valves is a competitive analysis of both the groups of butterfly valves as they cannot be used interchangeably and have different applications and features. From pharmaceuticals to food processing, oil production, and manufacturing, these valves come in handy in almost every business entity.
Lugged Butterfly Valves:
They are composed of metals like steel or ductile iron. They are similar to 3-piece ball valves and can be taken off without significantly affecting the other side.
In these types of valves, there are loops known as “ears” over the entire body, and the threads pass through these loops to enable the functionality of these valves.
Lug valves are mostly end function valves as they can be placed on the end of the line. One doesn’t need to stop the whole system to repair, replace, clean, or inspect a lug valve. It can be done in a jiffy by removing them. They will not affect the process. They don’t use extra bolts or nuts as their flanges already function as inbuilt nuts.
Advantages:
- They are easier to center.
- Lugged Butterfly valves are less sensitive to significant temperature differences. They don’t react intensively to a sudden rise or drop in the substance’s temperature.
- The chances of thermal expansion or contraction are reduced.
Disadvantages:
- They are heavier as their size increases and are made of heavy metals.
- They are more expensive than wafer-style valves or any other valve category.
Wafer Butterfly Valves:
They are designed to function as tight seals to protect against the dual directional heavy flow, which has enormous pressure differential on both sides. They act as a safeguard against the bi-directional force of pressure. They are engineered with four holes that align perfectly with the attached pipe. They have rubber valve seats that act as a firm seal between the valve and flange connection, meeting all the flange standards.
Unlike the other type, they cannot be placed at the end of the line, as the entire line needs to be shut off when they need to be repaired, cleaned, replaced, etc. Also, the functioning at one side of the line also affects the other side. They are trained to be compatible with electric actuation.
Advantages:
- They are lighter than the lugged type as they are made of lighter metals or materials such as PTFE.
They are cheaper.
- They have an easy installation process.
Disadvantages:
- They are not suitable as end valves as their entire functioning is dependent.
- They are difficult to position.
- Pipe flanges are separately required, unlike the lugged type where they are inbuilt.
Industrial Applications:
Despite the differences in structure, composition, and functioning, both lugged and wafer-style butterfly valves have been utilized in numerous industries. The significant difference is that in the case of the wafer-style valves, the body is annular, unlike the lugged valves. They can be shaped into their commonly defined structure using processes such as medical molding or PTFE molds.
These are some industries where you can efficiently use these valves:
- Aftermarket Custom Auto Parts Manufacturing
- Oil and Gas industry
- Pharmaceutical industry
- Food processing units
- Chemical processing
- Shipbuilding, etc.
Bottomline:
Choosing between the two types of valves depends on various factors such as your project needs, budget, time constraints, complications involved in projects, and other definitive components. Understanding that both categories of butterfly valves are necessary components in the functioning but cannot be used interchangeably is an essential step before selecting the valve. These categories have mostly replaced the ball valves in most industries, especially in the case of the petroleum industry, as they are cheaper and easy to use.