DEVICE FOR PIPE BACK SHIELDING

摘要

PURPOSE: A device for the back shielding of a pipe is provided to prevent an outlet of protective gas from blocking due to the melt down of deposited metal. CONSTITUTION: A device for the back shielding of a pipe comprises a pair of protective gas bodies. The protective gas bodies are formed in the inner bottom of a welded part of a rolled steel plate(10) to be separated from each other. Protective gas is supplied from the outside the steel plate to the inside the protective gas bodies. The protective gas bodies has a gas injection pipe(250).