Approximately 400M of tank supply and discharge lines were experiencing aggressive internal corrosion. In several areas there were 100% through wall anomalies that had already been repaired with clamps and welded sleeves. Ongoing NDE had detected many remaining areas that had wall loss in excess of 90%. A plan was needed to solve the problem without continuing to spot patch over the coming months and years.

It was decided that encapsulation of the entire system would be the best solution. Composite materials would be used to essentially construct a pipe on the outside of the existing pipe.

PRT Aquawrap® 400MSince the corrosion was internal, a barrier needed to be in place for the expected future through wall conditions. For this barrier component, PRT PowerSleeve® was chosen because of its 100% solids, impermeable epoxy matrix. It is impervious to the product contained in the line and provided the base layer for the repair design.

Because the project was on a tight schedule, it was decided to use PRT Aquawrap® pre-preg composite for the hoop strength replacement component of the project. Large coverage areas can be applied faster than the field-wetted PRT PowerSleeve® material. Since they are fully compatible systems, they were used together in order to capitalize on the advantages of each product.

The project began right on schedule from upper level scaffolding to surface preparation and onto each stage of the composite installation. It was a highly technical application that included many elbows, reducing tees, concentric and eccentric reducers and limited access work.

The client is a major Middle East oil producer and continually monitored and inspected the progress. Because of the right combination of the impermeable PRT PowerSleeve® and the speed of the PRT Aquawrap® the work progressed quickly. The project was finalized to the client’s complete satisfaction and closed out ahead of schedule in just 26 days.