A Triple Offset Butterfly Valves, also known as triple eccentric valves, are a versatile valve often used when in the harshest conditions of critical process environments. They are cost efficient, and alower torque option (easier to automate), than alternative style metal seated valves.

Standard TOSV design features include zero leakage with bi-directional shut off to API 598, a field replaceable seat and seal ring for reduced maintenance costs, non-galling design to enable a wide variety of marterial options, with options for live loaded packing and arduous duty bearing protectors.


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 include:

  • High pressure steam (over 150 PSI)
  • Superheated- steam
  • High temperature gases and oils

Patented Two direction valve geometry

The Solent & Pratt Triple Offset Segment Valve utilizes the well established valve geometry where the shaft is offset from the body in two directions (1) and (2), whilst the disc is a segment taken from a cone where the apex is offset from the center line of the valve (3). The disc (segment) of the valve houses a field replaceable metal laminate seal whilst the field replaceable seat ring is housed in the body of the valve.

Due to the valve geometry there is no interference or rubbing between seat and seal as the valve strokes through it’s full 90°.


  • Firesafe Certified to API 607 4th edition BS6755 Part 2 and API 6FA Sizes 3” (750mm) to 84” (2100mm) 
  • Anti-blowout stem Internal is standard External to API 609 optional 
  • Triple Offset Geometry Provides non-rubbing motion throughout full 90˚ rotation eliminating unnecessary wear and prolongs life of seat and seal.
  • Pressure ratings ANSI 150 through 300 Ib.Zero leakage Bi-directional shut-off to API 598, Zero Leakage Capability.
  • Ease of maintenance Field replaceable seat and seal ring reduces maintenance costs.Ease of material selection Non-galling design enables a wide variety of material options.
  • Bearing protectors Bearing protectors are available for the more arduous duties.
  • Live loaded packing Is available as an option.
  • Quality assurance system Approved by Lloyds to ISO 9001.
  • Operators Valves can be supplied with manual, electric, pneumatic or hydraulic actuators.
  • Fail-safe systems for emergency operation are also available.

What is the difference between double offset and triple offseat butterfly valves?Arrow

The main difference between a double and triple offset valve is the number of offset shafts; a triple offset valve has three. 

Two of the offsets 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.

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

What is the difference between Gates Valves & Butterfly Valves? Arrow
  • A gate valve uses a simple open/close movement, with the disc perpendicular to the flow direction. Gate valves are used in various applications, including large-scale systems that require an uninterrupted bi-directional flow of liquids and gases or uni-directional discharges at specific time intervals.
  • A butterfly valve uses a disc or offsets shafts that operate perpendicular to the flow direction. Butterfly valves are widely used in applications for regulating large volumes of liquid and gases. 
Why use a triple offset butterfly valve?Arrow
A triple offset butterfly valve is used in applications where a metal seat is required. A tight shut-off/on or a quarter turn actuation is desired, including high temperature and high-pressure applications.


At Curtiss Wright Valve Division, you’ll find various products suited to a wide range of industrial applications. Our range of valves includes Butterfly Valves, Changeover Valves, Check Valves, Control Valves, Directional Control Valves, Engineering Services, Engineering Software, Gate Valves, Globe Valves, Plug Valves, Pressure Relief Valves, Strainers and Instrumentation Equipment.

If you require any further information on any product, such as specification sheets, you can find them in the related documents or in the library


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