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 3^rd 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.