Introduction of a new field-applied corrosion system designed for pipelines
Proceedings Publication Date
One of the biggest challenges for field coating systems are pipelines which show a condensate film on the metal substrate. Such moist surfaces can be found on gas pipelines or coolant lines that are under load or when there is a high humidity in the environment (e.g. tropical climate etc.). Standard anti-corrosion coatings as PE/Butyl tapes, heat shrinkable sleeves or liquid coatings cannot be used under these conditions. Many operators try to cope with the situation by regulating the pressure of the pipeline, but there are numerous cases where this emergency measurement cannot be applied successfully. If existing coating systems were used the results were very often questionable. In the last years a few liquid epoxy systems were launched onto the market which could be applied on damp or even wet surfaces, however they all need mandatory grit blasting according to SA 2 ½ as surface preparation. This kind of surface preparation cannot be executed at all construction sites due to different limitations e.g. in refineries where this procedure is often not allowed while pipes are in operation. In this presentation we will introduce a new corrosion prevention system, which is best suited for damp and wet surfaces, needs only little pre-surface treatment and which can be executed under nearly all conditions on site. It is the combination of a water repellent petrolatum system and a self-amalgamating 3-ply PE-Butyl tape which provides a long lasting coorosion prevention and an excellent mechanical protection,too. High costs for line disconnections or long waiting times for rehabilitation measurements can be avoided. This corrosion protection system can be used for permanent operating temperatures up to + 60°C (+140°F). The problem how to cope with damp metal surfaces has been successfully solved. In the last months numerous field tests have been succesfully executed with operators in France and Germany.