Severn eliminates corrosion risk in firesafe valves

18 July 2019

Severn Glocon Group is extending its range of triple offset butterfly valves with a new solution that avoids galvanic corrosion in saline applications, without compromising firesafe capability.

The OCT®SW innovation was driven by market feedback from offshore oil and gas operators in relation to seawater service valves used for fire safety. It ensures graphite parts which can increase the susceptibility of neighbouring metals to corrosion when exposed to seawater do not contact line media.

Seawater service valves play an integral role feeding water in the event of fire on an offshore platform or vessel. Their ability to either supply or isolate sections of the water line is a critical safety feature. Eliminating galvanic corrosion while maintaining firesafe credentials has been an enduring challenge for the industry. Severn’s new valve design overcomes this limiting factor and recently passed fire testing in accordance with the latest editions of API 6FA, API 607 and ISO 10497.

Granted a patent by the UK Intellectual Property Office in 2018, Severn’s oblique cone technology (OCT®) is central to this new solution. The ‘infinite circle’ geometry of the design enabled the R&D team to develop a hybrid seal technology that eradicates the need for graphite.

To validate integrity, OCT®SW valves are exposed to a stringent fire testing procedure, involving a 30-minute burn where they are bathed in flames. Valves are monitored for leakage throughout the process. After a forced cooldown period, they undergo further seat and external leakage testing, and operational capability is also verified. The process is designed to simulate the time required to extinguish a fire, ensuring the valves can perform during and after an incident.