Root cleaning of I-groove welds
Thread Content
For the welding of the cylinder of pressure equipment with a wall thickness of 6 mm, I-shaped joints are used (without groove preparation), and the joint gap is 1 mm. The welding process involves first applying the first layer of weld manually from the inside of the cylinder, and then applying the second layer of weld using submerged arc welding from the outside. After the first layer of weld has been applied manually, is it possible not to complete the welding on the back side? If necessary, what method is the most labor-saving for root removal?
I’m not sure; if argon arc welding is used for the root pass, is it then unnecessary to clean the root?
For manual welding, apply a root pass on the inside, and ensure thorough cleaning of the root for the filling pass on the outside.
Since the thickness is only 6 mm, the diameter of the cylinder is likely to be small. In principle, submerged arc welding is more efficient for thicknesses of 8 mm or more, which makes it a reasonable choice. It is recommended to use an internal groove and manual welding; after cleaning the root on the outside, manual welding or submerged arc welding can be employed. The penetration depth achieved with manual welding is only about 2 mm. If a type I joint without a groove is used, deep cleaning of the root on the reverse side after manual welding is required, which does not ensure weld quality.