Severn’s engineering heritage and technical expertise have led to the OCT TOV Butterfly Valve being future-proof for changes in the process conditions to provide increased versatility for the end user.
From the outset, Severn made flexibility a key driving force in the design of the Oblique Cone Technology (OCT) Triple Offset (TOV) Butterfly Valve. Due to Severns extensive diverse engineering heritage and excellence, our expert team of engineers understand that processes and application product demands change over time, whether it is the process conditions or the overall requirements of the valve for the end user. Due to this understanding, the Oblique Cone Technology Triple Offset Butterfly Valve has been designed to incorporate multiple seal options, all fully interchangeable with each other, providing maximum application diversity and usability to ensure safe operations and minimum downtime.
The Laminate seal is the “traditional” Triple Offset Valve seal and consists of multiple metal and graphite layers providing isolation sealing.
he OCT HS seal is a hybrid polymer metallic seal, this seal benefits from a primary metal seal and secondary polymer seal, this provides a reliable and repeatable bubble tight seal time after time. This can also be paired with PTFE packings when graphite being in contact with the line media is a concern. The polymer seal is fully compliant with EN ISO 80079-36 (ATEX).
The OCT SW Valve takes the hybrid sealing to the next level with its versatile high performance. Severn utilises the OCT-HS seal and has designed a valve that ensure there is no graphite in contact with the line media to remove the risk of costly galvanic effects such as internal corrosion leading to valve failure. Whilst doing so the OCT-SW also maintains firesafe certification.
Should the sealing requirement not become as critical, and process conditions become more arduous, the Laminate and Hybrid seals can be changed for the OCT-SS solid seal. As the name suggests it is a solid metallic seal, that can be made from hard-wearing alloys to add longevity to the sealing life of the valve in arduous conditions and can offer a control valve seat leakage.
Based on Severns comprehensive history of severe service control, our team of engineering experts work closely with operators and end uses to identify the correct seal and material selection to provide the maximum reliability and productivity further ensuring minimum downtime.
All the OCT seals are interchangeable and can be upgraded without the need for main valve components being replaced, further emphasising the OCT TOV Butterfly Valves versatility. The fully in field serviceable valve can be upgraded on-site without the need for specialist tools or knowledge, this further ensures that costly unplanned downtime and site waste is kept to a minimum, along with potential loss in production for the end user. All the seal options can be changed on site within a small space of time to ensure site maintenance costs are reduced by upgrading the existing valve rather than discarding and replacing with a commodity product each time.
Each OCT valve is specially designed to be versatile and ensure it has multiple purposes for multiple conditions whilst still delivering maximum performance. With the introduction of the interchangeable seal, these can be easily swapped out to match the end users’ requirements, should they change.
The Triple Offset Butterfly Valve Cutting Edge Design Features Leads to Comprehensive Application Coverage.
Incorporating over 60 years of engineering excellence and technical expertise in valve engineering and application, Severn offers an industry leading and patented engineering technology solution(s) for Butterfly Valve requirements and applications with the Oblique Cone Technology (OCT) Triple Offset (TOV) Butterfly Valve. By utilising Severn’s ‘Repair Intelligence’ knowledge which involves providing real market feedback from extensive in-depth analysis from failed valves. Severn have designed each facet of the OCT TOV Butterfly Valve to provide the most accurate, reliable, and robust service capability and performance possible to help the end user achieve their core remit of safe operations and minimum downtime.
Severn’s OCT design uses circular sealing geometry, unlike traditional triple offset designs that use an ellipse. The benefit of circular geometry is that it provides a uniform sealing load around the circumference of the sealing diameter, providing a reliable and repeatable shut-off. By using circles rather than ellipses, it allows Severn to use proven circular sealing knowledge and incorporate this into the TOV Butterfly Valve.
In addition, to this we can also add specialised flow control trims that are traditionally found on double offset valves. These control trims include Anti Cavitation / Low noise, half baffle & full baffles. We can also add special features such as steam jacket and purge ports should they be required, onto our Triple Offset design.
Process conditions can change with time. Severn have ensured the interchangeability of the seal, should the sealing requirement not become as critical, or process conditions become more arduous. The HS seal can be changed to a laminated seal, or if conditions dictate, a solid seal. This can be done without the need for main valve components being replaced. The complete in-field serviceable valve can be upgraded on site without the need for specialist tools or knowledge ensuring possible down time and loss in production is kept to a minimum.
The interchangeability and versatility of the seal allows for Severn’s Triple Offset Valve to be used for both isolation and control applications and processes. The diversity of the OCT TOV Butterfly Valve and its functional usability for an extensive range of both isolation and control applications leads to the potential savings in stock holdings for end users who can use stock this one valve instead of stocking two. This in turn allows for potential cost savings for the end user on stock holding by reducing the need to stock multiple valves due to the extensive coverage that the OCT TOV Butterfly Valve offers.
Severn have designed all their Triple Offset Butterfly Valves with safety as paramount and therefore engineered the product with anti-blowout at both ends of the valve. This negates any chance of the shaft blowing out. The reduced shaft diameter at the drive end ensures the shaft cannot blow out through the packing follower and anti-blowout ring on the threaded shaft end ensures positive engagement without the need for additional fasteners.
The OCT range also comes with hard facing on the disc as standard with options to upgrade the standard hard facing to weld overlays such as stellite 6, ensuring and reliable seal and extended service life.
A quarter turn design ensures ease of actuation for both control and isolation purposes. Whether this be via an actuator or gearbox, the quarter turn design allows for simple operation.
As standard, Severn’s OCT TOV Butterfly Valve includes fugitive emission packing to ISO 15848 with options to change to meet customer specific requirements such as Shell 77/312 available.
The OCT valve range has been firesafe tested & certified in accordance with the strict fire test specifications set out in the standards ISO 10497, API 607 & API 6FA. Withstanding extreme temperatures of up to 1000°C whilst still sealing. Further underpinning the performance capabilities and validating the valve performance, ensuring this valve can be suitable for an extended range of applications and process requirements, leading to safe operations and reduction unplanned downtime for the end user.
Severn offer the OCT TOV Butterfly Valve in all cast materials. From basic carbon steels to specialist alloys such as Monel, Titanium & Hastelloy. Severn can provide the correct material selection for your application. Additional surface coatings such as stellite, armoloy, chrome or weld overlays are available upon application and request.
Fireproof Assurance: Severn’s OCT TOV Butterfly Valves Exceptional Fire Safety Design and Testing Credentials
As part of a safety-first approach Severn incorporates into its innovative Oblique Cone Technology (OCT) Triple Offset (TOV) Butterfly valve, fire safety is a critical part of that safety first objective. Fire testing standards state the minimum requirements the valve must achieve in order to receive fire safe certification. The standards dictate the setup & parameters required to simulate the conditions a valve may be subjected to during a fire, and test to ensure the valve can operate satisfactorily afterwards.
To summarise, the test consists of a valve being mounted in a fire test rig to flow water through the valve, and measure leakage both internally past the seal as well as externally through the packings and gaskets. The valves are then pressure tested at ambient temperature, once the valve has passed this element of the test, any leakage is recorded. The valve is then subject to a simulated fire by use of gas burners, with average temperatures of between 750°C & 1000°C recorded by thermocouples for the 30-minute burn time. Once complete, the flames are extinguished, and the valve is subjected to a forced cooldown using water to simulate the fire being extinguished on site.
The leakage during fire is measured and recorded. The valve is then subject to a re-ambient temperature and operational test, with the maximum leakage requirements being defined within the relevant standard. The tests are carried out in both the preferred and reverse directions and are witnessed by a 3rd party approval body to give added confidence that the valve will perform as required in either flow direction.
By investing in and developing their own on-site fire test facility, Severn can understand and interpret the results to re-design & develop the fire safe valve technology for the OCT TOV Butterfly Valve, to further exceed the requirements set out in the standard. By doing this, Severn have been able to achieve up to Zero seat leakage, even after fire testing, giving further confidence to the capabilities of the valves when installed and further ensuring safety first is achieved for the end user and their operations.
The key to Severn’s success lies in their patented Oblique Cone Technology (OCT), which received approval from the UK Intellectual Property Office in 2018. This innovative design uses an ‘infinite circle’ geometry that allowed the research and development team to develop the circular sealing geometry, which gives the flexibility to use the valve for both isolation and control duties with the option of interchangeable seals and control trims.
Utilising its over 60 years of engineering heritage, Severn have designed and developed the innovative OCT TOV Butterfly Valve, a valve that meets the requirements of API 6FA, API 607, and ISO 10497 fire testing standards. These bi-directional isolation & control valves offer repeatable zero leakage, providing peace of mind for operators while ensuring safety is at the forefront.
Severn’s certification for fire test covers the OCT Laminate, Hybrid (OCT-HS) and Seawater (OCT-SW) seals, achieving the required leakage rates in accordance with the relevant international standards. By designing, developing, and testing the hybrid seal (OCT-HS) Severn have been able to understand how the hybrid polymer metallic seal acts under extreme temperatures, which has enabled them to develop a graphite free, firesafe seal, that works even after being exposed to the extremes of a fire test. By using this knowledge, the OCT-SW utilises the hybrid seal technology and prevents any graphite from contacting with the line media, therefore on seawater service eliminates galvanic effects and extends the service life of the valve.
By meeting stringent fire test standards, they have provided customers with a reliable and efficient solution to fire safety. With their patented oblique cone technology, Severn have set a new benchmark for future valve designs and innovative technology and further ensure the end user achieves its core remit of safe operations and reduced downtime.
Exploring the innovative features and engineering principles of Severn’s OCT TOV Butterfly Valve that puts safety first.
At Severn, safety is paramount in the design of our products. With our background in safety-critical industries, Severn understands the importance of safety first for both our customers and employees.
As well as adhering to the strictest industry standards, Severn have identified that shaft blowout prevention was paramount to our end users and the wider industrial and process industries for improved valve performance and reduced operational downtime.
Butterfly Valve shafts are designed to connect to the disc with either dowel pins, taper pins, or keyways. The separation of the shaft and disc in service can be catastrophically dangerous. If any of these parts fail, the shaft may be ejected from the valve body. Shaft blowouts can occur when a coupling mechanism fails, therefore, disconnecting the shaft from the disc. With the pressures in the system, it may eject the unrestrained drive shaft through either end of the valve.
Not only is this projectile a huge safety concern but has the potential to compromise the pressure envelope of the valve allowing process to escape into the atmosphere.
Severn has designed all their Triple Offset Butterfly Valves as standard with anti-blowout incorporated at both ends of the valve. This negates any chance of the shaft blowing out if the pins were to fail. The reduced shaft diameter at the drive end ensures the shaft cannot blow out through the packing follower.
On the blank end of the valve, Severn have multiple features which prevents shaft blowout. The anti-blowout ring on the threaded shaft end ensures positive engagement without the need for additional fasteners. The blank end plate is locked in place and is designed to withstand full rated test pressures.
Dual anti-blowout devices are standard on the OCT TOV Butterfly Valve, meaning that even if the gland is removed, the secondary internal anti-blowout device will stop ejection of the shaft under the pressure, thus increasing both operator and plant safety.
Severn have designed their Triple Offset Valves to exceed the minimum wall thicknesses stated in ASME B16.34. Instead of just using the minimum allowance, Severn have gone above and beyond to ensure the safety of our products in the field for our customers.
Within Severn’s Triple Offset Butterfly Valve is a corrosion allowance. This means that the valve can afford to concede material to corrosion over time without affecting the pressure containing integrity or safety of the valve. The amount of corrosion may vary depending on the environment the valve is working in, but due to Severn’s engineering heritage and excellence, the OCT TOV Butterfly Valve has been designed to withstand changes in working environments and process conditions.
High MAST figures and safety factors are key when designing the Triple Offset Butterfly Valve. MAST is the Maximum Allowable Shaft Torque a quarter turn valve shaft can withstand during operation without mechanical failure. With Severn using higher MAST figures on their Triple Offset shafts, this helps maintain the structural integrity of the valve.
Sizing actuators correctly is a credit to Severn’s engineering excellence. Actuators, gearboxes, or any form of obturator that drives a quarter turn valve must be sized correctly by using the correct input and output torques. By torque testing the physical products prior to final inspection, we can compare the physical torques against our theoretical torques to maintain accuracy and consistency across the range.
Safety has always been at the forefront of Severn’s designs, and this is paramount in the 8500 Butterfly Valve range.
Severn’s engineering heritage and excellence has led to the innovative design of a product that can master both Control & Isolation applications.
Utilising Severn’s long history with Control Valve design, our team of engineering experts have been able to manufacture a Triple Offset Butterfly valve that can be used to provide superior control in both throttling and modulating service, whilst additionally providing a repeatable seal for isolation duties.
By designing a Control Valve that can isolate, rather than an isolation valve that controls (which may initially sound the same but is vastly different), Severn have designed a Butterfly Valve that maximises the Cv with streamlined internals to provide optimal flow characteristics when controlling the process.
We have also eliminated the need to have fasteners on the disc or a bolted-on seal, thus enabling us to optimise the disc profile. Additionally, by removing fasteners from the disc, we have eliminated the risk of loose fasteners falling into the line due to vibration.
By adopting a body-mounted seal we have been able to increase longevity & reliability of the product. As we have taken this out of the flow path of line media, this reduces wear on the seal allowing Severn to maximise the bore size for an increased CV.
Using our Patented Oblique Cone Technology (OCT), we can also use circular sealing geometry which provides an even seal load around the circumference of the disc. This gives us repeatable bubble-tight sealing, improving product performance, reliability, and safety, ensuring you achieve your core remit of safe operations and minimum downtime.
The OCT geometry enables Severn to add an extensive range of trims to the valve not traditionally found on Triple Offset Valves. By utilising a one-piece disc, Severn can add anti-cavitation trims, when conditions dictate, to help control the flow. This can also be paired with baffle plates when needed, enabling a Butterfly Valve to be utilised when severe service conditions may mean a standard Butterfly Valve would not be suitable or would have a significantly reduced service life.
The OCT Triple Offset Butterfly Valve can be utilised for both control and isolation valve applications, enabling the end user to significantly reduce stock inventory and overall operating costs. Parts are standardised and interchangeable, meaning end users can have a reduced spares inventory leading to further cost reductions.
It also provides the end users with the option to potentially utilise one valve that can perform both the control and isolation functions within a system, rather than two – leading to significant reductions in operating and service costs and weight saving – this can be paramount for weight critical operations such as offshore installations.
Explore the design that has been inspired by engineering heritage and excellence to create a product that master’s isolation and control applications.
From the outset, Severn wanted the Oblique Cone Technology (OCT) to be unique in the Triple Offset 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.
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 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. By looking at the traditional elliptical sealing concepts of 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 60 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. The 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 install 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.
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.
With over 60 years’ experience in the design and manufacture of Butterfly Valves, Severn launches a range built on decades of learnings and innovative engineering.
In the dynamic landscape of industrial engineering, innovation often stems from a rich heritage of expertise and an unyielding commitment to excellence. Severn Glocon, a renowned name in the world of valve design and manufacturing, have once again proven this statement true with the unveiling of the superior Oblique Cone Technology (OCT) Triple Offset (TOV) Butterfly Valve. This development represents Severn’s commitment to innovation in the realm of process and industrial energy markets, promising enhanced performance, reliability, and efficiency.
Engineering Heritage: The Foundation of Excellence
Severn’s journey to engineering eminence is woven with a tapestry of innovation and dedication stemming back over 60 years. With an engineering history extending back to 1957 and the design and manufacturing of Globe Control Valves, Severn has continuously pushed the boundaries of valve technology and design, earning a reputation for precision engineering and unmatched quality. Drawing from this extensive engineering heritage, Severn has consistently delivered solutions that exceed industry standards and address the evolving needs of diverse sectors.
Unveiling the Oblique Cone Technology (OCT)
At the heart of Severn’s latest engineering triumph lies the OCT TOV Butterfly valve, a revolutionary advancement in Butterfly valve design and performance. Unlike traditional Butterfly valves, which often suffer from limitations in sealing performance and durability, the OCT TOV Butterfly Valve introduces circular sealing geometry.
Unlike traditional triple offset designs that use an ellipse. The benefit of circular geometry is that it provides a uniform sealing load around the circumference of the sealing diameter, providing a reliable and repeatable shut-off. By using circles rather than ellipses, it allows Severn to use proven circular sealing knowledge and incorporate this into the TOV.
Incorporating Severn’s ‘Repair Intelligence’ knowledge which involves providing real market feedback from extensive in-depth analysis from failed valves. Severn have designed each facet of this valve to provide the most accurate, reliable, and robust service capability possible whether managing critical processes in Oil & Gas refineries, Chemical Plants, or Power Generation facilities, the OCT TOV Butterfly valve ensures the end user achieves their core remit of safe operations and minimum downtime.
Advantages for Process and Industrial Energy Markets
The introduction of the innovative OCT TOV Butterfly Valve designed by Severn signifies a paradigm shift in valve technology, offering a host of benefits to the Process & Industrial Energy markets
Enhanced Performance: Severn have designed each facet of this valve to provide the most accurate, reliable, and robust service capability possible to help the end user achieve their core remit of safe operations and minimum downtime.
Extended Lifecycle: Process conditions can change with time. Severn have ensured the interchangeability of the seal, should the sealing requirement not become as critical, or process conditions become more arduous.
Increased Safety: At Severn, safety is paramount to the design of our products and ensured that whilst adhering to the strictest industry standards, have incorporated shaft blowout prevention as a vital addition to the design of the valve to increase suitability for end users and the wider industry.
Versatility: Utilising Severn’s extended history of engineering excellence, the OCT TOV Butterfly valve has been designed for both superior control in both throttling and modulating services, whilst additionally providing a repeatable seal for isolation duties.
Environmental Sustainability: To further the commitment to reducing fugitive emissions and reduce the burden on end users to meet tightening specifications, all Severn’s OCT triple offset butterfly range offer the fugitive emissions packing sets as standard fitment on all standard valves in the range.
Severn’s relentless pursuit of engineering excellence has culminated in the development of the OCT Triple Offset Butterfly Valve – a testament to the company’s unwavering commitment to innovation and customer satisfaction. As industries worldwide seek ever-improving solutions to their operational challenges, Severn Glocon stands ready to lead the way, setting new benchmarks for performance, reliability, and efficiency in valve technology.