Advanced Welding Repair and Remediation Methods for In-service Pipelines

Overview

Main Objective

Develop low-hydrogen gas-metal arc-welding (GMAW) and flux-core arc-welding (FCAW) processes. Mechanize welding with multi-axis welding carriage and adaptive control/tracking for higher quality repair welds. This will allow in-service repair welding on future high strength/pressure pipelines where manual repair welding is not suitable. The overall objectives of the research are as follows:

• Develop an automated welding system for use on in-service pipelines;
• Implement a real-time adaptive control system to ensure reliable welding conditions;
• Evaluate system performance by performing laboratory trials; and
• Validate the system and gain regulatory approval by qualification of procedures, complying with recognized industry standards, and performing field trials.

Public Abstract

This project developed a prototype multi-axis automatic welding system with adaptive control and tracking for use on in-service welding repairs on liquid and gas transmission pipelines. The system is capable of deploying either gas metal arc welding (GMAW) or flux cored arc welding (FCAW) to weld pressure-containing sleeves (Type B), to weld reinforcement sleeves (Type A), or to directly deposit a layer of weld over an area to replace metal loss due to corrosion. The welding system was field tested at TransCanada in North Bay, Ontario and was demonstrated during a workshop at Edison Welding Institute in Columbus, Ohio. In addition, preliminary in-service welding trials with GMAW and FCAW were performed on high strength pipeline steels (X80, X100 and X120) to determine the susceptibility of hydrogen cracking, under simulated in-service welding conditions.

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