The internal and external coatings of the pipe protect it from corrosion and prevent chemical and mechanical interactions with the pipeline walls. The effectiveness and quality of the coating determines the quality and reliability of the pipe over time.
Corrosion can be defined as the degradation of a material caused by a chemical reaction with the environment and it is typical of metallic materials such as carbon steel pipes.
The most frequent causes of corrosion on the external surface of carbon steel pipes depend on different factors present in the site ground such as: resistance and aggressiveness of soil, local galvanic currents, stray currents ( i.e. near railways and undergrounds).
The most common causes of corrosion of internal surface depend on: deposit of condensation in case of aggressive fluids, chemical composition and suspended particles in conveyed fluids.
Corrosion cannot be totally avoided but drastically reduced by Passive or Active protection.
Passive protection is achieved with isolating coatings applied on the external surface of carbon steel pipes, able to reduce the exchange of current between external pipe surface and soil.
The external coatings are adherent to metal, resistant to impacts, abrasions, atmospheric aggressions and to all those factors mentioned here above.
They are made by bitumen, fiberglass, polyurethane, epoxy and polyester.
On the internal carbon steel pipe surface protective linings are made especially by bi-component epoxy paint, with different characteristics depending on the type of conveyed fluid.
These kind of coatings and linings fall within our plants capabilities. Active protection is made on site by anodes or impressed current.