Hot Tap Welding With Focus on Downstream and Chemical Applications

Abstract Hot tapping is a method of making connection to piping (or other equipment) by attaching a fitting to the system, usually by welding, followed by cutting through the pipe wall at the point of attachment utilizing an appropriate (hot-tapping) machine. This operation is generally carried out on a live (hot) system without decommissioning or interrupting flow. Focus of this paper is to discuss welding requirements for hot tapping for downstream and chemicals applications. This includes recommendations to improved requirements within ASME Section IX and API 2201 for in-service welding (welding on a piping system or pressure vessel or storage tank that is flowing or under pressure). Some requirements are covered in ASME PCC-2. Topics discussed in further details in this paper are; concentrations and operational limits based on services, commercial software capabilities and gaps, qualification requirements in ASME Section IX, ASME B31.3, ASME B31.1, API 2201 and ASME PCC-2 and comparison with API 1104, case histories on special services and recommendations for ASME Section IX, ASME B31.3, ASME B31.1, API 2201, ASME PCC-2 & API RP 582.