Plant Pipe Coating

Today it is difficult to find a large diameter pipeline that has not been built with plant–coated pipe.

Pipe coating plants are capable of applying various types of external as well as internal pipe coating. The plant must be configured to apply the type of pipeline coating specified.

Plants may be fixed or movable.

pipe coating plant

The choice of coating type depends on a number of factors, including:

• climatic conditions in the pipeline's area of operation,
• distance from the point of pipe coating location to the right–of–way,
• pipe transportation conditions,
• terrain conditions,
• type of product to be transported by the pipe,
• pipeline operating conditions.

Using automated design and production control systems, it is possible to establish a plant with equipment flexible enough to apply a variety of coatings.

plant application
of two–component liquid coating

Depending on the plant configuration, the following types of external coatings may be applied:

• Fusion–bonded powder coatings (FBE)

• Multi–layer extruded polyolefin such as polyethylene (PE)
  or polypropylene (PP) coatings — the latter has found substantial use in high–temperature and offshore applications.
  An epoxy anti–corrosion primer is applied to the pipe.
  It adheres to a normally non–compatible mechanical outer layer of polyethylene or polypropylene by means of
  an adhesive layer.
  
  This system arose in response to the perceived vulnerability
  of strictly epoxy coated systems.

plant application of multi–layer coating

• Multi–component epoxy and polyurethane coatings
  — epoxy coating is available in either “thin film” or double layer. The epoxy is the anti–corrosion agent.
• Hot tape coatings — iInclude the use of heat shrink tape
  as well as the Vanguard^® three–layer tape system and
  the Synergy^® hot tape system. Vanguard, sometimes called “three–layer in a tape”, produces a DIN compliant three layer coating when the tape is fused onto the pipe surface.
  
  Factory–applied tape systems allow the pipe coater to avoid expensive purchases of extrusion and other equipment normally associated with three–layer PE or PP coatings.

plant application
of multi–component coating

• Hot enamel coatings — coal tar or bitumen/asphalt coatings are applied in molten form with wraps of fiberglass and other felt tapes. While the coating life is excellent, HSE (health, safety and environment) concerns have diminished their use over time.
• Concrete heavy weight coatings

Pipe, which has been decommissioned from pipelines, may be taken to a plant for removal of the old coating and application of a new coating.

weight coating machine in action

In addition, internal coating materials may be applied including:

• Fusion–bonded powder coatings
• Multi–layer epoxy and polyurethane coatings
• Cement–mortar lining
• Coal tar and modified coal tar coatings

plant application of internal coating