In Situ Coating

An in situ coating should be pre-selected and tested to operate sufficiently in its operating environment. It must have an adequate pot-life to allow for enough time to load the batch into the pipeline, run the length of the line and recover the excess coating at the receiver. In long lines of 20 miles or more, a 6- 8 hours pot-life is needed. Pipeline Coatings used in the in-situ coating process used by IPS normally has a solid content in the range of 70-85%, with a typical viscosity of between 95-120 kreb units.

Most coating projects are designed to apply approximately 2 to 3 mils of coating per coating run, and normally require 3 to 4 coats to achieve the typical contracted dry film thickness (DFT). The drying time between coating runs is typically 16 to 24 hours.

The coating pigs will be modified, just before pipeline coating, to allow for the wall thickness of the pipeline and to allow for the type of coating to be used. Each pipeline has its own unique characteristics, which create some ambiguities with the first coating run. Normally, the first coating run will target a mil thickness just thick enough to fill the surface profile.

When the excess coating arrives at the receiver, it is removed and is normally placed back into its original container. The amount of coating received is recorded, with the difference between the amounts loaded and received, indicating the applied mil thickness for the in situ coating, as based on the manufacturer’s theoretical spreading rate.

In Situ & Corrosion Protection

If you are concerned about pipeline corrosion, call IPS to learn aout our internal pipeline coating process or pipeline rehabilitation. Our pipe coatings, sometimes called in-situ coating are performed with your pipeline in place.