Plastic for lightweight and corrosion resistant Subsea Equipment
Subsea environments lead to a number of significant demands placed on equipment, whether it is shallow or deep water environments. Two key issues to consider with all subsea equipment are weight and resistance to corrosive sea water. Our thermoplastics and composites offer significant weight savings over conventional materials like steel and aluminium: Our Polystone® grades (PE/PP) are naturally buoyant while engineering & high temperature grades plastics such as PEEK, PEI, POM, PK, nylon and PET are approximately 50% the weight of aluminium. Durostone® composites offering increased mechanical properties whilst only weighing approx. 25% the weight of steel. This coupled with polymers natural corrosion resistance, offers the potential for future subsea components to be smaller, lighter and free of cathodic protection – leading to efficiency and economic advantages in future equipment designs.
- Naturally corrosion resistant materials
- Weight reduction (reduced need for costly buoyancy)
- Long-lasting and low maintenance: resistant to corrosive salt water and hydrocarbons
- Economic advantages: Possibility for cathodic protection free equipment
Typical areas of application
- ROV components and equipment.
- Connectors (electronic and communication).
- Support structures (e.g. pipeline repair equipment, tee sleds, subsea tree frames).
- Subsea tree & wellhead components (protection/insulation)
Remote Offshore Vehicles (ROVs) are continuous being designed to operate in ever increasing depths. To aid this, we supply numerous corrosion resistant, key components used to assemble an ROV. This includes the naturally buoyant Polystone® P (PP) and Polystone® D (PE-HMW) used for the side frames. While electronics boxes made from SUSTARIN C (POM-C) have replaced metallic components, thanks to the materials lower weight and corrosion resistance. With the same corrosion resistance, low weight and excellent impact resistance leading to the use of SUSTAMID 6G for thruster nozzles and ROV buckets. More information about SUSTAMID 6G, SUSTARIN C, Polystone® P and Polystone® D
In offshore environments, oxidation of fasteners can rapidly happen, unless costly titanium or super duplex grades are used. An alternative to these are our Durostone® fasteners, which are not affected by oxidative degradation like steel. Durostone® fasteners offer high strength and are naturally corrosion resistant, as well as highly weather and chemical resistant, but also only weight approximately 75% less than an equivalent sized steel fastener. More information about Durostone® fasteners
Subsea (Christmas) tree end caps
During drilling the delicate wellhead is covered by a removal cap prior to installation/after removal of the subsea tree. As these are installed by ROV, weight is of a key concern. With thermoplastics like SUSTARIN C (POM-C), SUSTAPVDF and SUSTAPEEK offering significant weight reduction over traditional metallic components. Further benefits include the natural corrosion resistance of the material, as well as the thermal insulation properties and chemical resistance to the anti-fouling fluid. More information about SUSTARIN C (POM-C), SUSTAPVDF and SUSTAPEEK
As subsea equipment becomes more complicated, it is imperative that connectors both electrical & communication are machined and produced using material of the highest quality. SUSTAPEEK, SUSTAPEI and SUSTARIN C (POM-C) are the optimum solution with good electrical resistance, low moisture absorption, dimensional stability and impact resistance for Dry-Mate and Wet-Met systems. More information about SUSTARIN C (POM-C), SUSTAPEI and SUSTAPEEK
Subsea support structures
With our expertise and wide range of materials, we are able to offer the optimum material for metal replacement projects. This has included the replacement of metallic flanges/adaptor rings with thermoplastic alternatives, for which SUSTAPEEK has been selected. The combination of excellent load bearing properties, chemical resistance and dimensional stability resulted in the material selection. This was in addition to thermoplastics and composites natural corrosion resistance. More information about SUSTAPEEK
Arrange technical advice
The performance and reliability of materials used in the design of machines and systems in subsea applications are influenced by a variety of factors. These criteria need to be considered in order to make the right choice. Examples:
- Contact with corrosive seawater
- Extreme weather conditions (UV) and abrasion (sand/waves)
- Exposure to demanding hydrocarbon fluids, (H2S, production fluids, greases)
- Thermal cycling/exposure to both high and low temperatures
- Mechanical demands
- Tribological requirements (friction and wear)
We are happy to advise you on the selection of suitable materials for your particular application. Just use our contact form at the bottom of the page and write to us.