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Butterfly Valves

A butterfly valve is a valve that is used to regulate or shut off the flow of a fluid through a pipe. It is called a butterfly valve because its disk or plate that controls the flow of fluid through the valve resembles the shape of a butterfly wing. The valve uses a disc that rotates 90 degrees from open to close to block or control the flow in a piping system.

Norriseal-Wellmark’s Norris Butterfly valves are used in a variety of industries and applications from Oil and Gas to Food and Beverage. They are available in a variety of sizes and materials to suit different applications. We pride ourselves in offering high-quality valves in applications requiring reliable and repairable valves. Contact us today for a quote!

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Butterfly Valves

The Norris Advantage

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.

Industries we serve

Food & Beverage

The versatility and compact design of butterfly valves make them a popular choice in the food and beverage industry. 


High-performance butterfly valves are economic and easy to install with less maintenance required that is why they are used in a vast number of industrial processes.


Butterfly valves are durable and reliable and are best suited for the extreme environments and conditions of marine applications.

Navy & Coast Guard

On Navy ships butterfly valves are used for large capacity lines, such as forward and aft sea water suction lines, or lines from various tanks to their respective pumps.

Oil & Gas

Butterfly valves are widely used in the oil and gas industry due to their capability to deliver a high degree of durability and reliability to ensure long service and low maintenance needs of pipelines in oil and gas applications.


Butterfly valves are commonly used in HVAC systems to regulate airflow in ducts and dampers. They are also used in heating and cooling systems to control the flow of water or glycol.


Resilient Seated Wafer Style

Resilient Seated Wafer Style

• Available working pressure of 200 psi, 285 psi (ANSI 150) • Size ranges: 2” – 24” • Body materials:…

Resilient Seated Lug Style

Resilient Seated Lug Style

• Available working pressure of 200 psi, 285 psi (ANSI 150) • Size ranges: 2” – 36” • Body materials:…

Metal Seated Wafer Style

Metal Seated Wafer Style

• Available working pressure of 200 psi, 285 psi (ANSI 150) • Size ranges: 2” – 24” • Body materials:…

Metal Seated Lug Style

Metal Seated Lug Style

• Available working pressure of 200, 285 (ANSI 150) • Size ranges: 2” – 36” • Body materials: Ductile…

Operator Options

Operator Options

• Bare stem top works, or hold plates for mounting • On-off and throttling manual handles • Worm gear operators •…


    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.


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