Butterfly Valves

Compared to other valve types, butterfly valves feature a low profile, low torque requirements, bubble tight shut off, the ability to handle different media types, and can be paired with various actuators. Due to low torque requirements, butterfly valves are offered in large sizes with a smaller actuation solution.

• Angled disc design: Our competitors use a vertical disc design which compresses the seat at the 12 and 6 o’clock positions, causing frictional wear which will require more torque to operate the valve.  Norris’ differentiated design requires less torque and causes less wear on the seat.
• Three-year warranty: The only butterfly valve on the market with a three-year warranty.
• Sealing principal design: Independent body seals are used for flange sealing, which avoids the need to use a gasket during installation.
• Double shaft seal: The double shaft seals provide redundant protection against outside contamination of bearing areas and fluid leakage into the shaft area.

Butterfly Valve Parts

A butterfly valve typically consists of the following parts:

• Valve Body – The body of the valve installed between two flanges. Types of bodies are Span Wafer, Double Rib Span Wafer, or Lugged, and is a non-wetted component.
• Valve Disc – The disc is mounted inside the body and rotates 90 degrees against the seat to open or close the valve. Norriseal’s angle disc is designed to eliminate contact seat compression and allows for less torque to operate.
• Stems or Shafts – This part connects the disc to the actuation of the valve. It can be offered in different materials compatible with the media.
• Seat – Internal lining of the valve. The design of the seat matches the angle design of the disc to achieve complete shutoff at the closed position. Available as a resilient seat or metal seat in different materials.
• Seals – Multiple seals are present in the valve suited to the media and application. Extra shaft seals help prevent leaks to the outside of the valve from the inside. A disc seal is used for creating the positive shutoff with metal seated valves. Body seals allow the valve to be installed between the flanges without the use of gaskets and eliminate the pressure on the resilient seat.
• Actuation – Operation of the valve. Wide range of options such as manual handles, gear operators, pneumatic, or electric actuators. 

There can be slight variations in the design of butterfly valves depending on their application and type, but these are the most common parts found in a standard butterfly valve. If you have any questions, please contact us today for assistance in selecting the best option based on your specific requirements.