Contour Achieves Pressure Containment, Reinforcement on 6-inch Kickback Line

A Saudi Arabia-based affiliate of SABIC discovered significant internal corrosion on a 6-inch (152-mm) diameter pipe carrying ethylene during an inspection of its facility. The area requiring repair included complex geometries and previously installed repair clamps for a 14 m (46 ft) length as well as multiple valve bodies up to the valve stem in a high-temperature line where the content reached 148° C (298° F).

CSNRI experts designed a solution rated as a Class 3 repair, which is intended for produced water and hydrocarbons, flammable fluids, gas systems with pressures and temperatures more exacting than were present in this facility. Using a Class 3 repair in effect increased the thickness of the repair beyond the minimum requirement, providing an additional margin of safety.

A team of CSNRI trained and certified technicians grit blasted the area of the pipe to be repaired as well as the axial overlap to an SA 2.5 surface preparation, cleaning the damaged area to remove rust, coating, and mill scale to produce a near-white surface prior to the application of the Contour repair. The overlap section allowed a more secure bond between the metal pipe and the wrap outside the corrosion area. With the grit blasting completed, the line was flood washed with acetone to remove grease and dust before the installation began.

The installation team applied 4 plies of Contour wrap following precise instructions to ensure proper and safe application. With the initial wrapping completed for the first 4-m (13-ft) section, the team proceeded with the next section of the line, which covered an additional 6 m (19 ft) and included a long pipe clamp. Complex geometry and an uneven surface made the section of pipe with the elbow clamp more challenging. To add to the complexity, the repair had to be applied to injection nozzles over clamps. When this segment of the repair was completed, the team had arrested the original pinhole leak and completely wrapped the elbow clamp. The final segments of the repair were for a 2-m (6.5-ft) vertical pipe spool and a 2 m (6.5-ft) horizontal pipe spool up to its connection with a 12-inch (305-mm) diameter pipe.

This application of the Contour product required wrapping both bolted repair clamps, complex geometries and valve bodies, making it one of the more complicated Contour installations to date. Because the installation required no hot work, it was possible to keep the line in service under lower pressure for the entire repair. With the repair completed, the line was safe for another five years of service.