After the horizontal pressure vessel passes the hydrostatic test, a platform gasket is welded to the upper shell of the equipment – is it necessary to conduct another hydrostatic test? This device is not a post-weld heat treatment equipment.
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After the horizontal pressure vessel passes the hydrostatic test, a platform gasket is welded to the upper shell of the equipment – is it necessary to conduct another hydrostatic test? This device is not a post-weld heat treatment equipment.
I remember there being such a rule. Before leaving the factory, the container should be equipped with a reinforced version of the welding platform, so that welding does not damage the surface of the container, including the anti-corrosion coating inside the shell.
This is not necessary, but it does not comply with the manufacturing rules; the pad plate should be welded before applying hydraulic pressure.
Since it has no impact on strength, no heat treatment of the material is required, nor is a hydrostatic test necessary.
From the perspective of the purpose of the pressure test, if it is only a welding pad, there is no issue if a pressure test is not conducted; however, under normal manufacturing processes, the pressure test is carried out after the welding is completed (except between components that are not under pressure), so such a situation should be avoided as much as possible. However, the client should be aware of one thing: if the backing plate covers the weld seam, and if the inspection is conducted on a partial basis, then the weld seams covered by that plate need to be inspected again.
The welds between the backing plate and the equipment are classified as Class E welds; the correct manufacturing procedure involves welding them to the equipment first and then conducting a pressure test, which indicates inadequate control over the manufacturing process. The welds of the platform supports and gussets are not covered by the code requirements, and can be welded via pressure testing. Since the weld depth of the gasket plate and the equipment will clearly not exceed half of the wall thickness, it is not necessary to conduct a pressure test.
It’s not necessary, but the shims should still be welded before the hydrostatic test