Canada's Transportation Safety Board has reported significant corrosion problems in sections of the TransCanada PipeLines Ltd. system.
TransCanada is the main system for delivery of natural gas from Alberta to Canadian and U.S. markets.
The board released a report on three line breaks that occurred in 1991 and 1992, all attributed to stress corrosion cracking.
Another break occurred Oct. 7 near Cornwall, Ont., the day the board released its report on problems in the system. Cause of that break has not been determined.
Larry Gales, head of commodity pipelines investigations for the board, said the problem is serious and breaks will continue. He does not believe stress corrosion cracking caused the latest break.
TransCanada spokesman David Annesley said the company is spending about 75% of its $20-40 million (Canadian)/year maintenance budget to deal with stress corrosion cracking. The problem exists in older sections of line that were installed as long ago as the 1950s.
