What's Different About Zero, Double and Triple Offset Butterfly Valves?

Jul. 07, 2025

What's Different About Zero, Double and Triple Offset Butterfly Valves?

Choosing the wrong type of valve can be detrimental to your operation. There are a few different types of butterfly valves on the market, including the zero offset, double offset, and triple offset. I enlisted the help of Scott Telin, one of Crane’s application engineers and a member of our valves team, to help differentiate between the three offsets. If you aren’t familiar with all the terms mentioned below, be sure to download “The Ultimate Glossary of Valve Terminology”.

Link to LEFLOW

Zero Offset

Also known as a concentric design, this is common in general service ‘resilient seated’ or ‘rubber seated’ butterfly valves. The stem and disc are centered in the seat of the valve, all of which are centered in the body of the valve. The disc is in constant contact with the seat.

An advantage of this valve is the media going through the valve will not contact the body, since the seat is constructed as a sleeve or cartridge inside of the body.

Zero offset butterfly valves are used in basic and specialty liquid and gas applications up to 200 PSI and up to 400 deg F. The zero offset butterfly valve can handle chemicals, coatings, food, some solids, and abrasive applications.

The zero offset butterfly valve is available in epoxy coated cast iron and stainless steel with multiple seat materials such as Buna, EPDM, VITON, Teflon, Natural rubber and others.

Double Offset Butterfly Valve

This popular valve is also known as a high performance butterfly valve. This valve has two stems offset from the center. This creates a cam action during the application's process.

1st offset: The axis of the shaft is behind the centerline of the sealing point of the disc to seat.
2nd offset: The axis of the shaft is eccentric to the center of the valve/pipe line.

The double offset butterfly valve is generally used in:

Power generation
Pulp and paper
HVAC
Chemical
Oil and gas
Water and wastewater treatment
Shipbuilding

Double offset butterfly valves are available in higher pressures than the zero offset style. The double offset is up to ANSI Class 600 rating in carbon steel, stainless steel, Hastelloy and other body material, with variations of Teflon seats and also Fire Safe design with metal back up seats.

Triple Offset Butterfly Valve

With the triple offset butterfly valve there are three offsets. Two are placed in a similar position to the double offset butterfly valve, while the third offset is the geometry of the seating surface, creating a type of cone shape of the disc and seat. This cone angle, along with the two eccentric shaft offsets, allows the disc to seal against the seat with no friction.

This seat design also allows for uniform sealing, and thus a tight shutoff in a metal seat design. This design is a lower cost, lower torque option (easier to automate), than alternative style metal seated valves.

Triple offsets are generally used in applications similar to gate valves, where a metal seat is required, and tight shutoff and/or quarter turn actuation is desired. Applications like high pressure steam (over 150 PSI), superheated- steam, high temperature gases and oils, high temperature applications are good for this type of valve because a metal seat is required over a soft seat.

The triple offset valve is used in similar industries as the double offset butterfly valve, but in more demanding applications.

Bray Double Offset Butterfly Valves

What is a Bray Bronze Double Offset Butterfly Valve?
What are the key benefits of the double offset design?
What materials are used in the construction of this valve?
Where can the Bray Bronze Double Offset Butterfly Valve be used?
What sizes are available for the Bray Bronze Double Offset Butterfly Valve?
What type of actuation is compatible with this valve?
Is the Bray Bronze Double Offset Butterfly Valve fire-safe?
What are the pressure ratings for this valve?
What is the temperature range of this valve?
How does it compare to a triple offset butterfly valve?
Does the Bray Bronze Double Offset Butterfly Valve require regular maintenance?
Where can I buy a Bray Bronze Double Offset Butterfly Valve?

A Bray Bronze Double Offset Butterfly Valve is a high-performance valve designed for industrial applications requiring tight shutoff, reduced wear, and durability. The double offset design minimises friction between the disc and seat, extending its lifespan.

The double offset design reduces seat wear, improves sealing performance, and provides lower torque operation, making it ideal for demanding applications like marine, oil & gas, and chemical processing.

These valves typically feature a bronze body with options for a variety of disc and seat materials, ensuring excellent corrosion resistance and durability in harsh environments.

This valve is commonly used in marine applications, oil & gas, power generation, chemical processing, and water treatment plants due to its high resistance to corrosion and extreme temperatures.

Bray offers a wide range of sizes, typically from 2” to 48” (DN50 to DN), catering to different flow control requirements in various industries.

It can be operated manually using a lever or gearbox and is also compatible with pneumatic, electric, or hydraulic actuators for automated control.

Yes, many models comply with API 607 and ISO fire-safe standards, ensuring continued operation and tight shutoff in high-temperature conditions.

Typical pressure ratings range from 150 to 600 PSI (PN10 to PN40), depending on the model and application requirements.

Additional reading:
What cert for wellheads? - American Welding Society

If you want to learn more, please visit our website 2-Offset Butterfly Valve.

With the right seat material, this valve can handle temperatures ranging from -50°C to +250°C (-58°F to 482°F), making it suitable for extreme conditions.

While double offset valves reduce seat wear and improve sealing, triple offset valves take it a step further by using a conical sealing surface, which eliminates friction completely and is ideal for ultra-high-performance applications. These valves are designed for low maintenance operation, but periodic checks on the seat, disc, and actuator are recommended to ensure optimal performance and longevity. These valves are available through authorised distributors, industrial valve suppliers, and Bray’s official sales channels, ensuring genuine products and support.

Integrated into the top flange, this design maintains an uninterrupted bore, improving flow efficiency while minimising turbulence. Its reinforced structure offers greater resistance to shear forces, outperforming conventional pinned designs.

The high-strength, one-piece stem prevents blowout, ensuring maximum safety and extending the operational lifespan of the valve.

A fully adjustable, live-loaded sealing system meets international fugitive emission standards, offering a reliable and environmentally compliant sealing solution.

O-ring seals positioned within the top flange and travel stop act as a barrier against external contaminants, preserving the integrity of the packing area.

The energised resilient seat delivers zero-leakage bidirectional sealing while remaining isolated from the line media, enhancing durability and efficiency.

Designed for optimal bidirectional sealing, this feature ensures reliable performance across a broad range of pressures, from low to high.

The double offset stem and disc reduce seat wear, lower torque demands, and contribute to a longer service life, making operation more efficient

A continuous sealing surface between mating flanges ensures a secure, high-integrity seal, improving overall system reliability.

Top and bottom bearings provide firm stem support, minimise deflection, and resist corrosion, ensuring smooth and stable valve operation.

What is a double offset butterfly valve?
What makes Bray Double Offset Butterfly Valves unique?
What are the benefits of using a double offset butterfly valve?
Where are double offset butterfly valves commonly used?
How does a double offset design improve valve performance?
Where can I buy Bray Double Offset Butterfly Valves?
What materials are available for double offset butterfly valves?
Are Bray Double Offset Butterfly Valves compatible with various automation systems?
What kind of actuation options are available for double offset butterfly valves?
What seat designs are available for Bray Double Offset Butterfly Valves?
How do double offset butterfly valves compare to triple offset valves?
What is the pressure rating range for double offset butterfly valves?

A double offset butterfly valve has two offsets from the centerline of the disc and seat. This design reduces friction, increases durability, and improves sealing performance compared to a concentric butterfly valve.

Bray’s double offset butterfly valves feature high-performance seating technology, precision engineering, and low-friction operation, ensuring a longer lifespan and superior performance in demanding applications.

Double offset butterfly valves offer low operating torque, bubble-tight sealing, and longer service life due to reduced wear on the seat. They are also lightweight compared to other industrial valve types, making them easier to install.

These valves are widely used in industries such as water treatment, power plants, oil and gas, chemical processing, and marine applications due to their high-performance sealing and ability to handle high-pressure systems.

The dual-offset design moves the disc away from the seat during operation, minimising seat wear and providing a tighter, more reliable seal even in demanding applications.

Bray valves are available through authorized distributors and suppliers, including specialised valve and automation companies that offer expert selection and support for your application needs.

Common materials include stainless steel, carbon steel, ductile iron, and exotic alloys such as super duplex and bronze, depending on the application and media being controlled.

Yes! Bray’s valves are designed for seamless integration with Bray pneumatic and electric actuators, making them ideal for automated flow control systems.

They can be operated manually via a gearbox, or automated using pneumatic, electric, or hydraulic actuators for remote control and process automation.

If you are looking for more details, kindly visit Cast Steel Globe Valve-DIN.

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