Severn’s engineering heritage and excellence in valve manufacturing has led to the innovative design of a product that can master both Control & Isolation applications within critical flow control systems.

Utilising Severn’s long history with Control Valve design, our team of valve engineering experts have been able to manufacture a Triple Offset Butterfly Valve that can be used to provide superior flow control performance in both throttling and modulating service, whilst additionally providing a repeatable, bubble‑tight seal for isolation valve duties.

By designing a Control Valve that can isolate, rather than an isolation valve that attempts to control (which may initially sound similar but is fundamentally different in performance outcome), Severn has developed a high‑performance butterfly valve that maximises Cv through streamlined internal geometry. This delivers optimal flow characteristics, improved process controllability, and stable valve performance under variable operating conditions.

This distinction is critical for industries requiring precise process control, reliable shut‑off, and long‑term operational safety, particularly within oil & gas, energy, offshore, chemical processing, and industrial fluid handling systems.

Designing for Reliability, Safety, and Performance

Severn has eliminated the need for disc fasteners or bolted‑on seals, allowing further optimisation of the disc profile. By removing fasteners from the disc:

• Flow efficiency is improved
• Pressure drop is reduced
  Risk of loose components entering the pipeline due to vibration is eliminated

This approach significantly enhances operational reliability, particularly in high‑vibration and severe service environments.

By adopting a body‑mounted sealing arrangement, Severn has increased both the longevity and reliability of the valve. Removing the seal from the direct flow path of the process media reduces wear, enabling Severn to:

• Increase effective bore size
• Maximise Cv
• Extend service life in demanding applications

Patented Oblique Cone Technology (OCT)

Using Severn’s Patented Oblique Cone Technology (OCT), the valve utilises circular sealing geometry that ensures an even seal load distribution around the circumference of the disc.

This technology provides:

• Repeatable bubble‑tight shut‑off
• Improved operational safety
• Enhanced process reliability
• Reduced downtime and maintenance intervention

Ensuring customers consistently meet their core remit of safe operations and minimum downtime.

Advanced Trims for Severe Service Conditions

The OCT geometry enables Severn to offer an extensive range of control valve trims not traditionally associated with Triple Offset Butterfly Valves.

• By utilising a one‑piece disc design, Severn can incorporate:
• Anti‑cavitation trims
• Noise‑reduction solutions
• Flow conditioning elements
• Baffle plates for severe service control

This allows the valve to operate effectively in high‑pressure drop, high‑velocity, and erosive flow conditions, where a conventional butterfly valve would typically suffer reduced service life or performance limitations.

Reduced Inventory, Lower Costs, Greater Efficiency

• The OCT Triple Offset Butterfly Valve can be utilised for both control and isolation valve applications, enabling end users to:
• Reduce valve stock inventory
• Standardise spare parts
• Lower overall operating costs
• Simplify maintenance strategies

Standardised and interchangeable components further reduce spares holding requirements, delivering measurable lifecycle cost savings.

It also provides end users with the option to utilise a single valve to perform both control and isolation functions within a system, rather than two separate valves. This results in:

• Reduced CAPEX and OPEX
• Lower system weight
• Simplified piping design

These benefits are particularly critical for weight‑sensitive applications such as offshore installations, FPSOs, and platform‑based processing facilities.

Discover how Severn’s high‑performance control and isolation valve solutions can enhance your operation.

Explore Severn’s design that has been inspired by engineering heritage and excellence to create a product that Mastering Isolation Control Applications.

From the outset, Severn wanted the Oblique Cone Technology (OCT) to be unique in the Triple Offset Butterfly valve market. Severn wanted to develop a product that not only solves an extensive range of issues for the customer with our “standard” product range, but to break tradition, and to design and manufacture a technically superior Butterfly Valve Mastering Isolation Control Applications.  

By utilising their comprehensive history with specialist butterfly valve design and manufacture, Severn have been able to develop a Triple Offset Butterfly Valve that performs both control and isolation duty in a single package. A valve designed from the outset to be re-used, upgraded, and provide an increased level of safety to the end user. 

Severn Valves have utilised its years of experience in manufacturing both the concentric and double offset Butterfly Valves to create innovative technology that pushes the boundaries of Triple Offset Butterfly Valve design Mastering Isolation Control Applications. By looking at the traditional elliptical sealing concepts of Severn’s Triple offset valves and combining this with circular sealing principals, Severn created its patented Oblique Cone Technology (OCT). In its most simplistic form, the geometry can be compared to a circular cone, by moving the point of the cone along one axis, this creates two different angles to the cone sides (forming an oblique cone); by taking a slice of this cone, it forms the sealing geometry of the OCT valve.  

The benefit of this method means we maintain the principals of circular seals, thus providing an even seat load all-round the disc, therefore providing increased flexibility within the design to allow Severn to add different sealing options to the valve as well as specialist control trims such as anti-cavitation / low noise trims.  

By understanding the foundational principals of Butterfly Valve design, Severn have a detailed knowledge of the interaction between each and every Butterfly Valve component. This combined with Severn’s Repair Intelligence philosophy and over 65 years of engineering excellence, customer solutions and end user feedback, problems can be anticipated and resolved before they occur and therefore increasing the lifecycle of the product and reducing costly unplanned downtime.  

Severn additionally want to break the cycle of Butterfly Valves being a “throw away’’ commodity items. Severn’s OCT TOV Butterfly Valve is designed to be re-used, repaired, or upgraded on site with only basic tools. The robustness of the design means that the main components can be cleaned, soft goods replaced, and the valve can be reinstalled to provide extended years of reliable service. This not only reduces long term cost of ownership for the end user, but also reduces the environmental impact of the plant operations. Severn also installs Fugitive Emission certified packing as standard in the OCT to further reduce the plant emission. 

Flexibility and reliability come as standard in the OCT TOV Butterfly Valve. By using the principals of a Control Valve, Severn have streamlined and reduced the disc thickness to impede the flow as little as possible and maximise valve Cv. Fasteners have been removed from the disc, to eliminate the risk of them coming loose due to vibration and falling into the pipeline. The seal has also been mounted in the body rather than on the disc. This not only protects the seal by removing it from the direct flow path, but means the disc is thinner as well as giving Severn the option to add anti cavitation / low noise trims onto the disc when process conditions dictate mastering isolation and control application. 

The OCT principle has been installed and operating in the field for over 10 years without issues, this coupled with countless amounts of testing and validation including fire testing, pressure testing, temperature testing and cycle testing, provide the end user with confidence in the robustness and reliability of the OCT Triple Offset Butterfly valve range and ultimately minimise down time and plant costs.