How to ensure the roundness of small containers
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It’s a small electric heater housing, only DN200 in size, with two layers stacked together, and it is lifted using lifting lugs. Due to the small size of the cylinder, its roundness is prone to deformation during welding and lifting, which may make it difficult to insert the heating core. How can roundness be ensured? Should I raise this issue with the manufacturer? If that’s the case, how will the manufacturer solve it?
This post was last edited by simon.cheuang on 2010-10-20 at 19:46. Lifting should not have much impact on the roundness of the cylinder; however, the cylinder might deform when welding the lifting lugs. It can be supported by strut members inside the cylinder at the location of the lifting lugs, or a ring plate with an outer diameter equal to that of the cylinder’s inner diameter can be welded around the inside of the cylinder at those locations, just like the reinforcement rings used in pressure vessels to prevent instability; the difference is that the support ring is welded inside.
With such a small diameter, a tube must be used; generally, the smaller the diameter, the less likely it is to become out of round. The wall thickness is probably too thin; it’s impossible to insert a welding ring plate inside. Firstly, the diameter is too small to allow access, and secondly, the heating element cannot be inserted either. If nothing else works, it’s still possible to weld a ring plate on the outside