Which of the following inspections is not typically performed while piping systems are in service?

• A. Magma tests
• B. Flange surface inspections
• C. Vibration analysis
• D. Pressure tests

Answer: (B)

Flange surface inspections are generally performed during maintenance or shutdown periods rather than while a piping system is in service. These inspections involve checking the surface condition of flanges to identify any signs of corrosion, wear, or other defects that could compromise the integrity of the joint connection. Since these inspections may require access to areas of the piping system where the media must be isolated, they are typically carried out when the system is not under operating conditions.

In contrast, other inspections like vibration analysis can be conducted while the system is in operation, as they assess dynamic behaviors without requiring shutdown. Similarly, magma tests, often used to assess the integrity of welds and connections under pressure, and pressure tests, which confirm the system can withstand its operational pressure, typically occur during system commissioning or post-repair, rather than regular operational phases. Thus, the nature of the flange surface inspection makes it distinct as a practice performed when the system is not in service.