The coil consists of several seamless pipes welded together. There are up to 12 welded joints in one coil.
The welded joints are made by orbital arc welding with a non-consumable electrode under protection of shielded gas (argon). The welding process was performed by a certified welder by means of certified equipment.
The quality control of the welded joints was carried out by radiographic method.
We tested the products for strength at 48.5 MPa for 15 minutes.
