Trelleborg and Schoolhill in pioneering Shah Deniz project

Trelleborg Sealing Solutions has “pushed the barriers of science” to produce a “highly innovative” seal for a ground-breaking valve designed by Schoolhill Hydraulic Engineering for BP’s Shah Deniz field.

The pioneering high flow, high integrity, safety critical subsea QEV (quick exhaust valve), believed to be the first of its kind, has been created for a subsea HIPPS (high integrity pressure protection system) at the South Caspian Sea site.

Trelleborg created a bespoke version of its Captive Glyd Ring® in its low friction Zurcon® Z43 high modulus thermoplastic to feature in the QEV, which was selected as the seal was required to slide across mating surfaces that had dimensional changes. The seal is retained in a split groove, which prevents the sealing surface from getting damaged by a counter part with variable diameter or when passing holes.



The QEV has a 30-year design life with a valve qualification water depth range of 3,000 meters and a safety integrity level (SIL) rating of SIL3 with 23,000 accumulated cycles.

With a volume flow rate of 22 liters in five seconds (260 liters per minute), the device has been designed to ensure quick and safe emergency shutdowns on the ocean bed.

It is the culmination of a five-year project by Aberdeen-based Schoolhill Hydraulic Engineering. Trelleborg Sealing Solutions was commissioned to develop the seal.

David Brown, Global Lead Group Director Oil and Gas for Trelleborg Sealing Solutions, said: “Oil and gas exploration in hostile deepwater environments is demanding industry partners to continuously push the barriers of science in the pursuit of reliable and robust equipment.

“At Trelleborg, we pride ourselves on innovation and relished this opportunity to help create a high-pressure gas production valve for a HIPPS providing an extremely efficient shutdown. With huge volumes of fluid needing to rapidly exit via the system, we designed a unique sealing solution to maximize the performance of an already highly innovative product. We don’t believe another QEV of this type and performance is available anywhere else – it’s truly pioneering.”

Schoolhill Hydraulic Engineering Director Ronald Whyte said: “It seems a long time ago since we started this project. At the onset we knew we were taking on a lot, with the specifications we had to satisfy, notwithstanding the documentation and reporting required when working with a major oil and gas operator. It’s been a huge learning curve for Schoolhill, a small company with very limited financial resources.

“However, we are forward looking and believe that the step change provided by HIPPS for the oil and gas industry, will see many more operators going along this road. We believe this valve has a great future, which would not have been possible without the technical support provided by Trelleborg.”

Location: Shah Deniz Project, Caspian Sea