Metal-to-metal sealing. Meeting a precision engineering challenge
RED Engineering has always specialised in solving difficult problems, particularly in relation to more challenging installation, maintenance and decommissioning operations. But a recently completed project to design and test a gas-tight metal-to-metal seal for subsea operations called upon all the company’s creativity, skill, experience and commitment.
The Challenge:
RED was approached by Glacier Energy Services (Glacier), a specialist provider of engineered onsite machining solutions, to develop a metal to metal seal. With a proven range of onsite and remote machining products, the development of a bespoke seal arrangement would further enhance Glaciers capabilities to provide a turnkey pipeline machining service to global clients.
‘I think it’s fair to say that we have proved over the past ten years that we can deliver under pressure,’ says founding partner and Engineering Director, Richard Kent. ‘But this was a unique opportunity to prove ourselves in a difficult area of precision engineering, within an extremely tight timeframe.’
RED has established a global reputation for delivering excellence in the oil & gas sector, but although this project was for a subsea oil & gas application, it has also demonstrated the company’s ability to develop custom metal-to-metal (m2m) seals for the most demanding applications in other high-risk sectors.
‘Creating the perfect m2m seal is something of a Holy Grail for engineers,’ explains Richard Kent. ‘Existing sealing technology in the oil & gas sector is being pushed to the limits as operating pressures and temperatures of subsea wells continue to increase, and this is driving a demand for new, high-performance solutions. But m2m sealing is also of great interest for other sectors of the energy industries, including nuclear decommissioning.’
Critical applications
The two industries are both known to work at extremes of performance, and where engineering design must provide the highest standards of ‘risk management’.
‘In the subsea oil and gas industry, we’re designing complex m2m seals for critical applications to be utilised in dangerous, inaccessible, and hostile environments, where the negative consequences of a failure are well documented.
‘The parallels with the nuclear decommissioning industry are clear – an equally, if not more challenging environment where failure is not an option – this is why clients in both industries have to be certain they are getting the right solution.’
In many instances, the seals RED are designing and the applications they are designing them for are unique, so the solutions are unique and so are the tests.
Testing to new limits
That requires a rigorous approach to engineering design and development, with a practical approach to bespoke testing. RED has a 10-year track record of delivering both.
‘Even working to the tightest schedule, we have to be able to test our designs for these critical applications to find any faults or weaknesses, improve the design, test again and finally assure our clients that they are going to work. Any potential failure has to be exposed by the test programme so it can be rectified. This is an absolutely essential part of the process, and developing the test regime has required as much creativity and engineering expertise as designing the seals themselves.’
In many instances, the seals RED are designing and the applications they are designing them for are unique, so the solutions are unique and so are the tests, says Richard Kent. ‘Not only that, but for critical applications we need to test performance far beyond the specification in order to find out where the limits actually lie.’
‘We don’t just test our seals by over-pressurising or adjusting environmental factors,’ says the RED Engineering Director. ‘We also assess the impact of real world factors on the integrity of the seal. So for this project we developed a range of tests to assess the sensitivity of the seal integrity given varying operational factors – for example, incorrect torque settings, scratched and damaged sealing surfaces and incorrect threading.’
Understanding the application
One of the key benefits of the RED approach to designing unique solutions to unique challenges is their understanding of the practicalities of the industries, the environments and the applications they are designing for.
‘You have to fully understand the practical operational factors that affect not only how a design is going to perform, but also how the people using it are going to relate to it,’ agrees Richard Kent. ‘Good design is a marriage of form and function, so when we’re designing and testing an m2m seal, as we do in all our design work, we’re always conscious that it has to be as easy and safe to install and maintain as possible, as well as meeting the highest performance standards.’
This project has clearly demonstrated the benefits of the RED way – the design, rapid prototyping, testing and qualification of a custom m2m seal for a subsea application in just 20 weeks. But as far as the RED team is concerned, it was just another in a series of extreme engineering challenges to be solved with the skills, systems and process refined by RED over the past 10 years.
