IIAR 6 Appendix B Pressure Vessels Checklist | Part 9

Part 9: This is a continuation of our blog series explaining how to perform an IIAR 6 Appendix B inspection of an ammonia pressure vessel.

Item Q asks the inspector to verify that the sight glass is adequately protected from traffic, equipped with 360° guards, and configured with internal check valves if the glass breaks. The armored sight column below satisfies all of the requirements. It is worth noting that bull’s eye columns are not required to have the internal check valve protection.

When a vessel is insulated, the insulation system must be inspected per Item R. Deficiencies such as jacket damage, breached vapor barrier, and ice buildup must be noted. The high pressure receiver below is not insulated, so ‘N/A’ and ‘Not Insulated’ should be checked. A thermal imaging camera can be helpful to identify insulation system failures that cannot be observed with the naked eye.

For non-insulated vessels like this one, Item S requires the entire surface of the vessel to be inspected and any surface corrosion or pitting must be recorded as a deficiency. While not specifically listed in the checklist, ultrasonic thickness testing can be used to gauge the amount of material that has been lost due to corrosion. Thickness readings can be used to determine if the vessel is fit for service and the remaining useful life.

The checklist concludes with Item T which serves as a ”catch all” for other concerns that the inspector may have observed. The area below can be used to write a description of the deficiencies.

The previous blogs in this series are available in the following links. You can watch our free video of how to perform an IIAR 6 Appendix B Pressure Vessel inspection here.

• Part 1
• Part 2
• Part 3
• Part 4
• Part 5
• Part 6
• Part 7
• Part 8