Welded vs. drawn
11.1
Maintenance openings such as manholes, headholes or handholes have various functions in unpressurized vessels, such as inspecting weld seams or carrying out cleaning work. Both welded and drawn versions of maintenance openings are common for stainless steel wine tanks.
Fig. 1
Welded wine tank
The welded variants of maintenance openings have various disadvantages. The separate manufacturing process of the manhole insert, the welding and the subsequent cleaning of the weld seam are very complex work processes. In addition, the homogeneous grinding pattern is lost with the welded version.
Fig. 2
Trailed wine tank
Pulled maintenance openings are more cost-effective to produce and have a homogeneous appearance.