The connection of a new pipeline lateral or loop to an existing high pressure pipeline system has always been fraught with high costs and the potential for major system impacts. Pipeline owners and operators have historically had to choose between a traditional cold connection with its high associated costs and a less expensive but more mysterious hot tap.
Although the cost savings of a hot tap have always been considerable, they were not always sufficient to justify the risk of complications during the branch weld or hot tap or during the subsequent operation of the system. Despite their extraordinary costs and throughput impacts, the perceived certainties of cold connections were often sufficient to justify their regular use.
The recent Kyoto Protocol on Climate Change has resulted in new commitments by the world’s governments to reduce greenhouse gas emissions. For the North American gas industry, these initiatives could result in voluntary compliance objectives, incentive based programs or legislated reforms — any of which will have significant impacts on current practices.
TransCanada PipeLines Limited (TransCanada) has successfully managed the risk/reward conundrum and completed more than 700 large diameter (NPS 12 to NPS 30) horizontal high pressure hot taps without incident since 1960. TCPL’s research and development work has enabled it to refine its procedures to the point where it can now complete branch welding and hot tapping work with minimal effects on throughput, negligible emissions and no system integrity impacts. For TransCanada, the direct advantages of a hot tap over a cold connection have resulted in the avoidance of gross revenue losses of $1 million or more per hot tap, no environmental emissions, seamless service and no impacts whatsoever to shippers. TransCanada PipeLines Services Ltd. (TPSL) has further streamlined the supporting field procedures and now provides a complete turn key service to industry.