What is the maximum external inspection interval for Class 1 & 2 Piping?

What is the maximum external inspection interval for Class 1 & 2 Piping?

• A. 5 years
• B. 3 years
• C. 7 years
• D. 10 years

Answer: (A)

Inspection intervals are driven by how risky and critical the piping is. For Class 1 and Class 2 piping, which are the most consequential in many facilities, external surfaces are monitored on a tighter schedule because corrosion under insulation, coating damage, and other external defects can develop and progress without being seen from the inside. To keep the chance of a failure low, the standard sets a five-year maximum for external inspections of these classes. This upper limit ensures regular checks to detect corrosion or damage early. If past inspections show very slow corrosion or a formal risk assessment supports it, the program can justify adjusting the interval, but the default ceiling for these classes is five years.

Inspection intervals are driven by how risky and critical the piping is. For Class 1 and Class 2 piping, which are the most consequential in many facilities, external surfaces are monitored on a tighter schedule because corrosion under insulation, coating damage, and other external defects can develop and progress without being seen from the inside. To keep the chance of a failure low, the standard sets a five-year maximum for external inspections of these classes. This upper limit ensures regular checks to detect corrosion or damage early. If past inspections show very slow corrosion or a formal risk assessment supports it, the program can justify adjusting the interval, but the default ceiling for these classes is five years.