Scenario

Piping is typically sourced at 6 or 12 meters long sections completed with the usual factory pre-coat of a robust anticorrosive protective coating such as fusion bonded epoxy or a multilayer polyolefin system for along and extend pipe life. The ends of each pipe length are left unprotected referred to as a "cutback" so that when welding the pipe sections together during the construction of the pipeline, the coating is not damaged. Pipeline field welds are necessary because the piping system has to be broken into pieces for transportation and has to be in pieces of manageable size for handling into place during construction.

Offshore and onshore gathering, transmission and distribution pipelines cross a variety of environments, many of them challenging and even extreme. These pipelines are also extended to going deeper and have increasingly high operating temperatures. Cathodic protection in the form of sacrificial anodes is also normally installed to help provide corrosion control. Since, these offshore pipelines are welded together in either single of double joint segments; there is a need to apply a coating at the weld locations to reinforce the intactness of the joining.

Shaic also provide Heat-shrinkable sleeves (HS 340, HS 3401, HS 3401 HT80, HS 3402) and PE backing butyl rubber wrappig tape (AC 700) as option to protect the entire pipeline include girth welds.

Remedy

The field joint is the area where two pipe joints meet and are welded together to extend the pipeline length. The welding joint area (cutback section) remains as bare steel and must be protected against corrosion and thermally insulated in order to avoid creating corrosion-prone areas or cold spots in the pipeline or the complete subsea production structure.

Heat-shrinkable sleeves HSS or butyl rubber wrapping tape AC 700 series are applied onto the cutback at the field weld or "field joint" during the construction of a pipeline. Heat-shrinkable sleeves have an adhesive that sticks the sleeve to the cutback and to the original factory applied mainline coating. The sleeve also acts as a corrosion protective layer. The backing provides mechanical protection against abrasion and soil stress forces after the pipeline is buried. Heat wrap tape may also be used in addition for pipe bends, or as an alternative method for wrapping the whole pipe.

SHAIC – Anti Corrosion Tape (AC 700 Series)

Solutions

SHAIC  - the international coating systems brand offers a complete range of cold applied & heat shrinkable field-applied specialty coatings such as heat shrink wraparound sleeves (Heat Shrink Sleeve (HSS), Butyl Rubber Wrapping Tape (AC700) and Horizontal Directional Drilling (HDD) which provide unbeatable on-shore, offshore corrosion protection solutions for oil, gas and water transmission pipelines joints and other substrates.

Born of the atomic age armoured with optimal resistance as 3-layer and 2-layer systems with epoxy primer and hot melt polymer they are both impressively meet international standard especially cathodic disbondment and hot water immersion test even at maximum rated operating temperature with their ability to perform safely and efficiently.

Further in catering to demanding applications to protecting metal pipes structures in contact with an electrolyte (soil, water) SHAIC coatings come with high electrical resistance and low permeability to hydrogen and oxygen. They are also physically strong and chemically stable. Additionally, for requirements of applications, e.g. high operating temperature which necessitates specific tailoring of coatings is also achievable with SHAIC. SHAIC is also renowned for line of anti-corrosion coating tapes for water pipeline reliably ideal for metal pipes, underground steel pipes and bare bends and girth-weld joints of PE, epoxy & PP coated pipes by hand or machine applications.

Typical applications for SHAIC can include:

• Bend, Elbows, Fittings, T's
• Horizontal Directional Drilling (HDD)
• Field Applied
• Girth Weld
• Heat Shrinkable Sleeve
• Pipeline Coating Rehabilitation
• Pipeline Rehab
• Repair Sealing
• Water Pipe

Products

Cold Applied Tapes (AC 700)
AC700 wrapping tapes for corrosion protection safeguard against acids, alkalis and other corrosive materials - with polyethylene backing and butyl rubber-based adhesive.

Epoxy Primers -  Waterproof, non-porous materials that protect the bare metal from oxidation.

Corrosion protection of field welded joints for pipelines 3-layer system with epoxy primer up to 85°C.Water resistance, corrosion inhibiting, excellent adhesion.

Heat Shrinkable Sleeves -Corrosion protection of field welded joints of pipelines. Long term protection, strong backing, outstanding water proofing with high chemical resistance for use on carbon steel, cast iron and  ductile iron pipe joints.

Various Features and Benefits of SHAIC Products

• Long term corrosion protection
• High strength
• Compatible with factory coating
• Simple application to complex problem
• High chemical resistance
• Cost Saving
• Not dangerous
• 2 layers/3 layers Systems

Situational Context

As most pipelines are a network and extend for long distances there will be many field joints where the pipeline sections are joined and welded together. Proper field joint anti-corrosive liquid coatings such as epoxies, urethanes, heat shrinkable sleeves and sometimes fusion-bonded epoxy are required for the field joints, as a result, it is imperative that the protective coatings applied to pipelines be seamless for the whole length, with no disparities between the systems on the pipe lengths and the weld joints.