The Severn Glocon Group has announced a High Integrity Pressure Protection Systems (HIPPS) for oil and gas topside and subsea applications. The subsea HIPPS will be the first to combine independent electronic and mechanical systems to provide a dual redundancy, pipeline pressure protection system.
Until now subsea HIPPS has been exclusively electronic, relying on pressure transducers and logic analyser voting logic to activate the two final elements, arranged in series within the pipeline, with each valve capable of independently isolating the flow when closed. However, concerns over wax deposition and hydrate formation desensitising the transducers have limited the take up of the pipeline pressure protection system.
The Severn Glocon subsea HIPPS adds a mechanical HIPPS alongside the electronic HIPPS, providing a second, independent, pressure protection system. The mechanical HIPPS system is more resistant to hydrate and heavy wax build-up, and significantly less likely to be impaired by such deposits. Using the mechanical HIPPS valves in a parallel, ‘layered’ arrangement provides a second line of protection in the event of a fault with the electronic system.
Rated SIL 1 – 4, the electronic and mechanical HIPPS systems are designed and built in accordance with IEC 61508 and IEC 61511 safety instrumented systems (SIS) standards. Severn Glocon’s mechanical HIPPS comprises two pairs of pressure sensors linked to two final elements, each controlled by two independent hydraulic control sub-systems.
“Adopting the layered approach to subsea HIPPS using a mechanical HIPPS system is an elegant and simple solution to eliminating the potential risks associated with electronic HIPPS,” says Robert Walker, director, Severn Subsea Technologies. “It allows subsea HIPPS to be deployed more widely as operators seek to tie-back high pressure marginal fields to existing pipeline infrastructure and topsides.”
Severn Glocon’s topside electronic HIPPS system features isolation valves that can be maintained in-line, avoiding the cost and disruption of removing the valve during process maintenance. In addition, the valve design permits the pipeline to be pig inspected.
Severn Glocon takes an integrated approach to HIPPS system design, assembly and test. The Group’s HIPPS facility enables Integrated Factory Acceptance Test (IFAT) bringing together the HIPPS components and customer and Classification Society in a single space for validation and testing of the HIPPS.
“Severn Glocon’s HIPPS systems represent a new generation of HIPPS systems offering levels of customisation at every stage of the process from design, assembly, testing and implementation, no other company offers the complete HIPPS system service,” notes Mr Walker.
For example, Severn Glocon offers HIPPS closure time customised to reflect actual rather than theoretical requirements – the industry references a 2 second closure, however, this may jeopardies other parts of the process, creating a pressure surge that compounds the initial problem.
The Severn Glocon Group is able to offer a full ‘Functional Safety Management’ service. It has a dedicated HIPPS design, assembly and test facility. All HIPPS projects are performed using a standard design methodology, ensuring consistency of interpretation of IEC 61508 and IEC 61511, and HAZOP Study; under the responsibility of Certified Functional Safety Professionals.