Pressure testing of safety critical subsea equipment is a crucial step to ensure that vehicles, and their supporting technology, can withstand the high pressures and extended submersions of the subsea environment.
Forum Energy Technologies (FET) provides essential pressure testing of subsea equipment, boasting one of Europe’s largest horizontal hyperbaric testing facilities in Kirkbymoorside, UK. With the ability to cater for all types of testing, whether it is hyperbaric or hydrostatic, the company has the in-house capabilities and equipment to accommodate clients’ needs.
The testing facility is utilised by a variety of different sectors including oil and gas, defence, the scientific community, and telecommunications, facilitating equipment security and ensuring the safety of future operators.
Most recently, the facility has been used to test Triton’s 3300/3 submarine which supported the filming of aquatic-based nature documentaries, including the award-winning Blue Planet II hosted by Sir David Attenborough, and enabled man’s first underwater encounter with the giant squid.
Independent testing capabilities
FET’s testing facility operates eight pressure vessels of different sizes and specifications available that can be used for various types of testing with water, oil, or gas. The company can also provide live testing of the electrical or hydraulic functions within the pressure vessels.
Upgraded testing tanks, 20 tonnes safe working load lifting cranes, experienced personnel and detailed procedures are in place offering independent testing for all types of subsea, defence and oceanography equipment, following the client’s test specification.
The largest testing vessel measures 2.3 metres diameter by 8.1 metres length and is rated to 3,500 psi (241 bar), allowing operators to assess equipment at the high pressures encountered during subsea operations. It has a maximum load capacity of 70-tonnes, including the weight of water, and holds approximately 43 m3 of water. Installed with a HMG300 Hydac system, the vessel can also accurately and efficiently capture data, including pressure, temperature, and flow throughout assessment to provide precise operational updates.
For assessments, the large chamber is pressurised using an electrically driven water pump which can pressurise to a maximum rate of 58 psi per minute. There are a maximum of 22 penetrations for electrical, hydraulic, pneumatic, and instrumentation.
The horizontal loading system simplifies the installation and hook-up of test equipment, and a 20-tonne overhead crane is also on-site to assist with heavy equipment testing. The hydrostatic pressure test vessel is fitted with a detachable semi-ellipsoidal end cap for easy loading of components. All testing is carried out to the highest standards and in compliance with Health and Safety Executive Guidance GS4 Standard.
For hydrostatic testing, the vessel features a secure area in which internal assessing can be carried out for various items such as electrical cables and boards, manifolds, function of manipulators, torque tools, submarine hulls, camera and light encased equipment, hot stabs and receptacle, gas cylinders and emergency life support store pods, amongst others. This also allows for pressure testing up to 30,000 psi.
In addition to the hydrostatic pressure test centre, FET’s facility hosts a 6-metre-deep tank available for wet commissioning or full-scale interface tests. Measuring 9 metres wide by 11 metres length, the tank is ideally suited to enable ROV and ancillary testing.
FET has a dedicated engineering team and skilled technicians based at the premises to assist in testing operations. Recent upgrades mean that tests can be done 35% faster than previously, delivering greater efficiencies.
Improvements include enhanced pumps, which can reduce tank filling by 45 minutes. The tank’s door, which is fitted on train tracks and is pulled in using a winch, has also been upgraded with the latest technology, allowing it to be opened and closed 1.5 hours quicker than before, creating significant time and cost savings.
Wide range of expertise
FET’s in house welding and fabrication capabilities, as well as its state-of-the-art electronics lab, mean that the company can be a one-stop-shop for equipment testing, handling the procedure from start to finish. The company’s teams have the skills, expertise, and equipment to help clients with atypical, bespoke jobs.
The firm’s testing capabilities also proved crucial for the testing of Triton’s 3300/3 submarine, which was famously utilised in Blue Planet II, Sir David Attenborough’s Great Barrier Reef, and the BBC’s Galapagos to film remarkable natural footage for the documentaries.
Triton’s submarine is 13.1 feet (4 metres) in length and 9.8 feet (3 metres) in width and is capable of carrying both the submarine pilot and two passengers. The vessel can also reach an impressive depth of 3,280 feet (1,000 metres) and can travel at a maximum speed of 3 knots, whilst being able to maintain this activity for 12 hours.
The submersible’s pressure boundaries were subjected to an over-pressure test prior to the vessel being launched commercially, to demonstrate compliance with the DNV rules for classification.
For example, whilst the submarine typically reaches depths of 1,000 metres, equivalent to 101 bar, Triton’s acrylic sphere assembly was subjected to an external pressure of 121 bar for over an hour before it was released. After this initial test pressure was again built up for a second cycle, further confirming the dependability of the vessel in highly pressurised environments.
After the acrylic pressure sphere assembly is hydrostatically tested, it gets installed, and forms the key part of the Triton 3300/3 submersible.
The purpose of the hydrostatic testing was to prove that the submarine has the strength to withstand a nominal test pressure 20% greater than the nominal design pressure.
“It was a Triton 3300/3 that allowed man’s first ever encounter with the giant squid underwater and it is the submersible of choice for researchers, filmmakers, and adventurers due to its large interior, generous payload, and modular expandability,” comments Jarl Stromer, class and regulatory compliance manager at Triton.
“We are grateful for FET’s support in testing the submarine and ensuring it complies with all relevant safety regulations. The extensive testing the company provided provide us with peace of mind and confirmed that the design, materials, and workmanship of this unique piece of technology are up to the higher standards.”
Bespoke testing scenarios to high standards
With its advanced systems and specialised services, FET testing facility is well-placed to support a variety of different sectors. In the testing of Triton’s 3300/3 submersible, the company showcased its capabilities to provide bespoke testing scenarios whilst maintaining the high standards that customers have grown to expect.
The support FET provides in product testing through its hyperbaric testing facility is imperative for the global subsea industry and it’s vital that service companies continue to invest in these premises to ensure they can meet the every-changing demands of the industry.