Gas & Oil Tank Interior Protection
Metallic pipelines and storage and shipping tankers are often fabricated from carbon steel and low grade alloy steel that is coated with primer and epoxy for chemical resistance. However, they are still prone to be corrosion as a result of electrochemical reactions with the environment.
The type and rate of corrosion are closely dependent on material properties and environmental conditions. Corrosion can develop internally and externally, and because the mechanisms inside and outside of storage and shipping tankers are different they require different protective coating properties to prolonging useful life.
Recent studies[1] of INTERIOR corrosion in oil and gas lines have found that the mechanism of corrosion is in sour fluid, mixed with H2S and CO2 corrosive gases that can penetrate traditional epoxy coatings. When combined with the moisture and water molecules small enough to pass through these same coatings, this can result in acidic and cathodic corrosion, pitting and weakening, and eventually fracturing and leakage.
Any effective coating, whether an over-coating of an original epoxy coating or a direct coating applied to the steel surface, must have the ability to create a seal against these small corrosive elements. That's why AIT's FLUOROSEAL® coating boasts tight molecular packing of the fluoropolymers, which help block corrosion before it begins.
Block H2S, CO2, and Other Corrosive Gases from Permeating the Coating/Steel Interface INSIDE your Oil and Gas Storage Tanks and Transport Pipes:
- AIT FLUOROSEAL® coatings are engineered with the performance of highly fluorinated polymers to exceed the performance of traditional “FEVE” and PVDF coatings.
- These unique fluoropolymer coatings can be used inside of oil and gas transport pipes and storage and shipping containers because its molecular structure blocks H2S, CO2, and other corrosive gases from penetrating the metal/coating interface, causing pitting and other corrosion failures.
- Applied as a high fluoropolymer over-coating to the inside of storage and shipping tankers and piping can extend the service life and capability of traditional epoxy coatings.
- Field applicable and ambient curing to abrasion resistant fluoropolymer for high shear liquid flow.
- A VOC-free, brush or spray coating with strong adhesion to structural epoxy coatings. Its high polarity also adds to the chemical resistance of existing epoxy coatings.
Field and Factory Applicable FLUOROSEAL® SCX-7180-PTE Coating for the INSIDE of Oil and Gas Pipes:
- For most pipes, special brushing or spray coating tools are needed to apply directly to the inside of an epoxy-coated pipe. Two coats are usually recommended to ensure full coverage.
- For smaller long pipes, the following method may be applicable:
- Prepare a platform where the epoxy-coated pipe can be rolled around its diameter at least one complete round.
- Prepare a polyolefin (PE or PP) plug for both side of the pipe.
- Plug one end of the pipe. Pour enough FLUOROSEAL® SCX-7180-PTE (starting with one gallon, adding more to cover at least 1 inch above the bottom side of the pipe) inside of the pipe and plug the opposite end.
- Roll the pipe at least 2 times around its diameter.
- Empty the excess coating by slightly tilting from one side. Collect the excess and seal for use as adhesive-sealant for pipe-to-pipe assembly.
- Allow the wet inside coating to dry-to-the-touch for at least 10 minutes before moving or transporting to staging area.
- Move the coated pipes to staging area and allow coating to cure for at least 3 days under temperature above 20°C. More time will be required for lower temperatures.
- FLUOROSEAL® SCX-7180-PTE will cure (cross-linked) at ambient temperature to hard coating that is ready for use.
- For larger volume factory applications, the same heat curing process of epoxy coating may be used.
- SCX-7180-PTE curing process is similar to most other epoxy coatings and takes seconds to cure at temperatures above 150°C.
- Cured FLUOROSEAL® SCX-7180-PTE, with a thickness of just over 50µm (2-mil), is a powerful fluoropolymer coating that protects the inside of the steel pipes against H2S, CO2, and other corrosive elements that mix with water to cause pitting and other damage.
Field Applicable Sealing-Coating of the Joints between Oil and Gas Pipes:
- Brush coat the joints (inside and outside mating area) with SCX-7180-PTE and allow to dry for at least 10 minutes.
- Assemble the pipes as usual.
- Inspect with UV fluorescent light to ensure complete coverage. Patch brush with additional coating if needed (can be any time after the initial coating).
- Cured FLUOROSEAL® SCX -7180-PTE is a strong and effective fluoropolymer sealant against oil and gas leakage.
Field and Factory Applicable FLUOROSEAL® SCX-7180-PTE Coating for the INTERIOR of the Oil and Gas Storage and Shipping Tankers:
- If the INSIDE of the oil and gas tankers are being refurbished, clean off all rusted areas, loose paint and other debris and solvent clean to prepare the surface.
- For use of FLUOROSEAL® SCX-7180-PTE, user has a choice of either directly brushing or spraying over the original surface or over surfaces that have been re-coated with an epoxy coating.
- A good practice is to coat twice to ensure complete coverage and reach more than 50µm (2-mil) thickness.
- Inspect with UV fluorescent light to ensure complete coverage. Patch brush with additional coating if needed (can be any time after the initial coating).
- Allow the coating to dry to-the-touch for at least 10 minutes. For foot traffic, allow at least 3 days of ambient curing. More time is required if temperatures are lower than 20°C.
- FLUOROSEAL® SCX-7180-PTE will fully cure (cross-linked) at ambient temperature to a hard coating that is ready for use in 7 days.
- Cured FLUOROSEAL® SCX-7180-PTE with thickness of just over 50µm (2-mil) is a powerful fluoropolymer coating that protects the inside of steel oil and gas storage and shipping tankers against H2S, CO2, and other corrosive elements that combine with water to cause pitting and other damage.
Novel FLUOROSEAL® Coatings for Field Brush or Spray Applications
Almost all high fluoropolymer coatings are only available for factory coating and curing. Novel FLUOROSEAL® coatings, while containing a higher percentage of fluorination than normal PVDF and FEVE coatings, are ambient curable to an abrasion resistant hard coating. They are engineered for use as over-coating protection, as well as a direct coating over steel and concrete. Their proven fluoropolymer molecular structure seals against UV, moisture and water, salt-spray and fog, along with H2S, CO2, SO2, and other corrosive gases.
In the protection of oil and gas storage and shipping tankers and transmission pipes that have been coated with traditional epoxy coating from corrosion from INSIDE. FLUOROSEAL® coatings can dramatically prolong the useful life based on its ability in blocking the H2S and CO2 that are known to cause the damage that epoxy coating with its molecular structure and packing cannot provide such protection.
The following are some of the unique protection capabilities:
- For the INSIDE of new pipes and tankers with an epoxy coating, FLUOROSEAL® coatings can be applied as a transparent over-coating in just 50µm thick for unparalleled protection against H2S and CO2 induced corrosion. High fluorination FLUOROSEAL® coatings are now available in field applicable ease brush-spray coatings and are crosslinked for tough abrasion resistance to high shear flow.
- Outstanding adhesion to cleaned metals with or without an original primer coating. That is, it can be field brush or spray coated on rusted areas that have been prepared by removing rust, flaking paint and other debris.
- For the OUTSIDE of new pipes and tankers with existing epoxy coatings, FLUOROSEAL® coatings can be applied as heavier pigmented coating for extra protection, extending the maintenance period by 30-50 years. The high fluorination FLUOROSEAL® coatings have been proven effective for horizontal and vertical UV blocking and resistant protective coating.
- This high fluorination molecular packing structure is proven to block the penetration of moisture and corrosive gases, providing unparalleled protection for structural epoxy and/or polyurethane coatings against water immersion, salt-spray, and salt-fog for pipes and tankers near the ocean.
- With major polymer glass transition (Tg) at below -45°C and the high temperature stability of fluorinated polymers, FLUOROSEAL® coatings provide long-term protection from tropical to polar climates.
- FLUOROSEAL® coatings can be used as an over-coating or original coating and cure to a tough, abrasion resistant finish for direct foot and vehicle traffic.
- FLUOROSEAL® coatings for pipes, tankers and supporting structural applications are all VOC-free and can be used anywhere in the world.
