scope:

General

Manholes and inspection ports must above all permit an assessment to be made of the longitudinal and circumferential welds, and of points where there are particularly high stress concentrations and points where there are particularly high stress concentrations and points at risk, at the inner faces of pressure vessels. Points where stresses are particularly high can be regarded as including corner welds, end-plate flange regions, and the areas surrounding large cut-outs. Points at risk include, for example, the liquid sump and vessel bottom, the region in the vicinity of the surface of the liquids, and points which - as experience has shown - are particularly subject to corrosion and erosion.

Inspection ports may be necessary in addition to a man-hole in those circumstances where, for example, as a consequence of the presence of internals, moving about inside the vessel is insufficient on its own to permit an assessment to be made. The inspection ports provided in accordance with clause 2 may be replaced by smaller openings; in the event of this being done, such openings shall then be provided in larger numbers and at suitable points.