Butterfly valves are widely used in industrial pipelines for regulating and stopping the flow of liquids and gases. They feature a circular disc (called a ‘butterfly’) that rotates within the valve body to open or close the flow path. Butterfly valves offer simple design, low cost, easyoperation and quick opening/ closing action. As reputy valves manufacturer and supplier in China, today, we will comment about butterfly valves in various types:
The Three Main Types Of Butterfly Valves Based On Body Construction Are:
Lug Type (Flanged Valves)
Lug type butterfly valves feature a body with integral flanges or lugs. The butterfly disc is fitted between two ‘lugs’ extending from the body.The disc seals against the face of the lugs or flanges. Normally, we call it double flange butterfly valve.
These valves are suitable for larger NPS sizes, higher pressures and severe services. The double-flanged construction allows easy installation between adjacent flanges of the pipeline.
Lug type butterfly valves are available in a wide range of dimensions as per international standards such ANSI, DIN,JIS and BS. Large size double flange butterfly valve with discs up to 120 inches in diameter are used for high-flow industrial applications.
Wafer butterfly valves have a body designed to be sandwiched between flanges of the adjacent pipeline. The body has Wafer-style ports that match the flange drilling of adjoining pipes.
Since wafer butterfly valve does not have integral flanges, they offer compact design and lower cost compared to lug type valves. They are mainly used for smaller NPS sizes and light-medium duty applications.
The wafer body is compressed between two ANSI/ASME or other standard flanges to complete the pipeline connection. Special gaskets are used to seal the body between the flanges.
Lugged Wafer Type
Lugged wafer butterfly valves combine features of lug and wafer type bodies. They have integral lugs with drilled holes to facilitate bolted installation between flanges.
The lugged wafer design offers advantages of bolted connections as well as compact size. As the body sits between the adjoining flanges, shorter length of pipe is required compared to lug type valves.
These valves are commonly used for medium-heavy duty industrial applications having NPS sizes between 2 to 40 inch and ANSI pressureclass ratings up to 2500.
Key Factors To Consider For Selecting Butterfly Valves
• Valve Duty – Indicating required flowrate, pressure rating and close-off class for proper valve sizing.
• Temperature and Media – Type of fluid and operating temperature range for suitable material selection.
• Pipe Connection – ANSI, DIN or JIS flanges; threaded or grooved ends as perspecific piping system.
• Actuator Type – Manual,pneumatic or electric actuators based on requirements for automated or remote operation.
• Sealing – Suitable sealing for prevention ofcasing leakage in high-pressure applications.
• Other Factors – Space requirements, maintenance access, vacuum compatibility, double shut-off capability and more.
Leading butterfly valve manufacturers offer standard as well as custom designed valves with various options to meet project-specific needs. They provide valve materials, pressure ratings and sizes as per different international standards for global applicability.