Surfaces depend on selection of process tube/inner tube. Out of the Dockweiler stainless steel tube systems for gases are mostly used:
Ultron, TCC.1 or finetron.1

surfaces metal bright, anodic clean and electropolished
finetron.1, TCC.1

Characteristics/Advantages:
The specially developed cleaning process removes 3-5µm from the surface – and with it any remnants of the annealing process and other potential contamination. For the user this means a surface free of particles including the welds.
Anodic cleaning does not alter the roughness of the inner surface.
Ultron

Characteristics/Advantages:
Minimization of the real surface, closed chromiumoxide layer increases the corrosion resistance, optimized orbital welding behaviour, no catalytic influences on the transported medium.
Ra ≤ 0,80µm
Oberflächenbearbeitung von Rohren