Orbitally welding tubes to tube sheets can be done using either manual TIG or orbital TIG. Orbital welding saves time and produces high quality welds. The welds are documented to ensure optimal traceability of the welding process.
At AXXAIR the orbital tube-to-tube-sheet welding process is carried out with the SATP-80X machine, which features the following functions:
ATTENTION:
We would first like to emphasize that these tube-to-tube-sheet applications can be complex and require knowledge of the preparation and geometry of the tube assembly.
AXXAIR provides machines that are capable of welding these configurations, and we can share our experience with you, but AXXAIR is not responsible for the welds and welding results. It is the responsibility of the customer to decide, according to the specifications of the heat exchangers, how to prepare and place the tubes in the tube sheets.
Needless to say, this decision has a direct impact on the outcome of the weld.
All weldable materials can be used in tube-to-tube applications. However, the dimensions of the tubes used in these applications are limited.
The diameters generally range from 12.7 to 101.6 mm (5 to 40”) for thicknesses between 0.5 and 5 mm (1/5 to 2”). The majority of applications work with diameters between 19.05 mm and 38.1 mm (3/4 and 1.5'') and thicknesses between 1.65 and 3.4 mm (2/3 and 1.3”).
Almost all industries use heat exchangers, but they primarily made their way into the chemical, petrochemical and energy industries.
General Characteristics
The equipment used also differs slightly depending on the type of application and the level of automation required:
It can be used for double pass applications but sometimes manual adjustment of the electrode between passes is required.
Please note: Centering tools not manufactured by AXXAIR must be adapted to the position of the tube in the tube sheet.
The contact area between the tube and the tube sheet must be perfectly clean and free of grease or oil or other substances as this would create bubbles in the weld bead which is not permissible.
The tubes must NOT be expanded in the tube sheet before welding as the gases emitted during the weld would not be able to evacuate and would cause an "explosion" at the end of the welding process. Automatic welding would then be impossible.
Watch our video dedicated to the machine SATP80X :