An alternative to shot down by using hot tapping and plugging method / Mohd Nazri Salleh and Amran Sa'ri

Hot taps (or pressure taps) provide a means to add connections to piping, pressure vessels and other process equipment and tankage without disrupting normal process operations. Hot taps can also be used to make connections into equipment where it would be impractical to prepare the equipment for hot work such as internally loose lined vessels or long runs of piping. Connections attached by hot tapping can also be used for plugging or stoppling to isolate sections of piping. Hot taps should, however, be used only where it is impractical to take the equipment out of service. Each hot tap must be evaluated individually by using sound engineering judgement and by considering all potentially adverse conditions. Design of the hot tap connection and reinforcing pad, if necessary) should be in accordance with the proper code (e.g. ASME Pressure Vessel Code, API 650 Specification for Welded Storage Tanks, ANSI B31.3 Code for Pressure Piping). Fittings and valves should be evaluated to be sure they would accommodate the process conditions and the hot tap machine.