Composite Reinforced Line Pipe (CRLP) for Onshore Gas Pipelines

There has been a general trend in the natural gas pipeline transmission industry towards high-pressure pipelines using higher strength steels. However, as the strength has been increased, so have issues of weldability and fracture control. TransCanada PipeLines has been developing and testing a hybrid product since 1996 called Composite Reinforced Line Pipe (CRLP^®) to address these issues. This is a patented technology developed by NCF Industries and licensed on a worldwide basis to TransCanada PipeLines. CRLP^® is composed of high performance, composite material reinforcing a proven high-strength, low alloy steel pipe. The composite reinforces the steel pipe in the hoop direction, thereby increasing its pressure carrying capacity, while providing a tough, corrosion-resistant coating. This paper discusses recent research work concerning the use of CRLP^® for large-diameter gas pipeline systems. Aspects discussed include analysis and design methodologies, full-scale testing, and field trials.