The splash zone, the area immediately above and below the mean water level, has long been a major concern to both design and corrosion engineers of offshore installations.
Tides cause the water level to rise and fall, alternately wetting and drying exposed metal surfaces, such as offshore oil and gas platform legs and risers.
The brackish water and exposure to oxygen is corrosive, the wave action is constantly eroding the metal members and debris and boats come in contact with the metal to cause damage. Most common areas affected are risers, J-Tubes, bends, spools, and pipe field joint.
The metal, which is constantly submerged, can usually be protected by cathodic means, but that won’t work in the splash zone because the water level is constantly changing. The areas well above the splash zone, which are exposed only to atmosphere, can be protected with various paints and zinc coatings, but they must be reapplied when necessary.
Oil platform rise splash zone coated with Mark Tool's SplashTRON® pipeline coating
Protecting this zone with traditional above and below solutions have proven unsatisfactory. Monel jackets welded to the metal surface; special coatings and sprayed-on paint; and even making the metal components thicker, of course, are not effective in the splash zone.
Protection of the Splash Zone
The criteria for successful splash zone protection consists of the following requirements:
- Metal surface isolation – metal must be isolated and separated from the environment, such as with materials with properties similar to rubber or polyurethane
- High electrical resistance – coating should inhibit electrolytic corrosion and resist electrical current flow
- High impact resistance – protects against and resists buffeting from boats and floating debris
- Flexible – won't crack under the distortion of pipe bends or twists
- Bio-fouling resistant– isolate metal from sea life, fungus, and scale attack
- Good thermal insulation – important in the case of flow lines
- Guaranteed for life – should last virtually the life of the installation
The tough, yet flexible, SplashTRON® is uniformly bonded to the metal surface that will be exposed in the splash zone in thicknesses of 1/4", 1/2", 3/4", and 1". It resists impact damage, features exceptional weatherability, requires no routine maintenance, has excellent insulating properties (thermal and electrical), and can be used at temperatures from -45°F to 200°F.
Common applications of SplashTRON® include platform structural members (legs and diagonals), conventional risers, pipelines pulled through J-tubes, conductors, and the lining of riser clamps. Mark Tool has coated offshore platforms with SplashTRON® for two decades.
The tough, long-lasting elastomer is applied to structural members exposed to the splash zone during fabrication. It provides complete protection against the erosive action of abrasive-laden seawater, the harsh attack of ozone and ultraviolet rays, incidental impact from boats and floating debris, and the effect of sea life which builds upon all offshore installations.
An important feature of SplashTRON® in platform coating application is the fact that it is completely and permanently bonded to the metal surface, and because it is flexible, it won't crack or disbond as the members bend, expand, and contract. SplashTRON® can be expected to protect against corrosion for the life of the platform. SplashTRON® has proven its effectiveness in the Gulf of Mexico and other offshore areas around the world for more than 30 years. It is used by the leading producers of oil and gas, and most transmission companies.
SplashTRON® is a high density elastomer splash zone coating for splash zone protection featuring excellent resistance to weathering, fungus, marine life, and most oils. SplashTRON® is applied in our plant in Garden City, Louisiana (near Franklin), in California, as well as Japan, to pipe of practically any length and diameter. We also manufacture SplashTRON® sleeves which can be applied in the field and used where more than one joint of pipe is needed for splash zone protection, as in J-tube pulls. The sleeves fit over welded areas of the pipe and are bonded to the pipe with a two-part structural adhesive that we supply. SplashTRON® is also an excellent material for use in J-tube plugs and lining for riser clamps.
More on the splash zone and SplashTRON®: SplashTRON® Review