Use of hot taps for gas pipelines can be expanded

TransCanada PipeLines Ltd., Calgary, has relied on hot tapping to complete more than 700 large diameter (12--30 in.), horizontal, high-pressure hot taps without incident since 1960. A hot tap is a method of joining a new tie-over pipe to an existing and loaded facility such as a pipeline or tank. The objective of the procedure is to cut an interconnection hole in the facility through a valved hot-tapping assembly without the need to evacuate the contents. A successful hot tap will minimize operational effects and result in no spills or emissions. In this discussion, the generic term hot tap will include all of the technical operations necessary to prepare for and complete the interconnection of a new pipeline with an operating pipeline. The design, installation, and quality-control operations of a hot tap are described.