What is a common requirement when performing inspections on insulated vessels?

When conducting inspections on insulated vessels, a key requirement is to evaluate underneath the insulation for corrosion. Insulation can trap moisture and contaminants, creating an environment conducive to corrosion that may not be visible from the outside. Inspectors need to assess the condition of the underlying surfaces to identify any signs of corrosion or degradation that could compromise the integrity of the vessel. This is crucial because unchecked corrosion can lead to potentially dangerous situations such as leaks or vessel failure.

While temperature variations and the operational state of the vessel are important considerations, they are not the primary focus of inspections specifically aimed at identifying physical damage or degradation due to corrosion. Regularly replacing the insulation is also not a common inspection requirement; instead, the focus is on assessing the condition of the insulation and the underlying material to determine necessary repairs or maintenance. Conducting inspections solely during vessel shutdowns may be practical in certain situations, but inspections can often and should take place while the vessel is in operation, depending on the assessment needs and safety considerations.