Session: MF-24-01 Materials and Fabrication for Refining-1

Paper Number: 154748

154748 - Automatic Submerged Arc Welding System in Heavy-Wall Pressure Vessel Fabrication 

Abstract: 

An operator of Submerged Arc Welding (SAW), which is used for welding the longitudinal and circumferential joints on cylindrical shells of heavy-wall pressure vessels, is required to perform highly skilled tasks. These tasks include setting welding conditions, determining the number of welding pass distributions, and adjusting wire targeting positions and welding conditions depending on the groove shape. After welding, the SAW operator needs to do supplementary works, removing slag, supplying flux, and cutting wire for subsequent welding. From the above, one SAW operator cannot handle multi joints at once and the SAW operator handles only one joint currently. Furthermore, for welding an outside groove on circumferential joints, the SAW operator needs to climb to top of cylindrical shells. This process imposes a physical burden on him and requires careful attention to safety. To solve these issues, an automatic SAW system was developed. This system enables even a less experienced SAW operator to handle two joints and improves productivity. Moreover, by enabling remote operation, this system reduces a physical burden and ensures safety.

The components of this system include an automatic sensing unit for detecting the groove shape, an automatic welding algorithm for setting the wire targeting positions and welding conditions depending on the groove shape, automatic supplementary work units, and a remote-control unit that combines cameras and welding monitoring devices. By integrating these components, the automatic SAW system was composed.

This system was applied to longitudinal and circumferential joints on cylindrical shells of heavy-wall pressure vessels. This system proved that one SAW operator can handle two joints, regardless of his skill. Furthermore, for circumferential joints, it was proved that this system enabled the SAW operator on the ground to weld the joint of cylindrical shells remotely. By applying this system, it has been expected to improve the quality of longitudinal and circumferential joint welds on cylindrical shells of heavy-wall pressure vessels and shorten the fabrication schedule.

Presenting Author: Masakatsu Nakano Kanadevia Corporation

Presenting Author Biography: I graduated from the Department of Materials Engineering at the University of Tokyo with a master's Degree
in 2014.
I Joined Hitachi Zosen Corporation (now Kanadevia Corporation) in the same year.
Since joining the company, I have been engaged in research and development work, including
the development of 9%Cr steel pressure vessels and automated welding technology.
I participated in PVP in 2019, and my presentation was titled "IMPROVEMENT OF LOWTEMPERATURE TOUGHNESS IN WELD METAL MADE OF 9CR-1MO-V STEEL BY GTAW METHOD".

Authors:

Masakatsu Nakano Kanadevia Corporation
Kenji Kamikawa Kanadevia Corporation
Yuichi Kobayashi Kanadevia Corporation
Takahiro Fujimoto Kanadevia Corporation
Masamitsu Abe Kanadevia Corporation
Mitsuyoshi Nakatani Kanadevia corporation