12inch (323mm) DR17 PE100 / PE4710 pipe installation in calgary, alberta [PE]

In late 2008, ATCO Gas completed installation of 3 km (2 miles) of 323 mm (12 in.) DR 17 PE 100 / PE 4710 gas main in Calgary, Alberta, Canada. This was the first DR 17 pipe used by ATCO Gas. This was also one of the Company’s first HDPE projects. MDPE is more commonly selected for natural gas distribution applications in Canada. ATCO Gas plans to install more HDPE pipe to address potential concerns related to RCP for large diameter pipe. The Company has selected compounds that are expected to improve the long term performance of the pipe while reducing cost. The first installations presented many challenges as the Company wished to install yellow DR 17 HDPE pipe. DR 17 is not a commonly used size, but offered an opportunity for cost savings. The PE 100 / PE 4710 compound also offered better performance characteristics. New fusion procedures were developed and some issues around fusibility were identified and resolved. Squeeze off performance of the pipe is still under investigation. In addition to introducing this new material into its system, ATCO Gas has also been working closely to revise Canadian standards to recognize newer PE material. The goal is to gain regulatory acceptance as well as internal acceptance of the HDPE material.