For soil-to-air inspections on uncoated lines, excavation depth is recommended at:

For soil-to-air inspections on uncoated lines, excavation depth is recommended at:

• A. 2-4 inches
• B. 12-18 inches
• C. 1-2 feet
• D. 6-12 inches

Answer: (D)

When inspecting uncoated piping in soil-to-air conditions, you must expose enough of the pipe surface at the soil interface to clearly assess corrosion indicators and the condition of the metal. Since there is no coating to shield the metal, the exposure must be deep enough to reveal the true surface condition and any wall loss or pitting right at the soil contact, while not unnecessarily disturbing more soil than needed. Exposing about six to twelve inches around the pipe strikes that balance. It provides a representative window to visually inspect the exposed surface and the surrounding soil conditions that influence corrosion, without over-excavating. Shallow exposure (a few inches) may hide surface defects, while much deeper digging (twelve inches or more) isn’t required for routine soil-to-air checks and adds risk and cost. Therefore, six to twelve inches is the appropriate depth for this scenario.

When inspecting uncoated piping in soil-to-air conditions, you must expose enough of the pipe surface at the soil interface to clearly assess corrosion indicators and the condition of the metal. Since there is no coating to shield the metal, the exposure must be deep enough to reveal the true surface condition and any wall loss or pitting right at the soil contact, while not unnecessarily disturbing more soil than needed.

Exposing about six to twelve inches around the pipe strikes that balance. It provides a representative window to visually inspect the exposed surface and the surrounding soil conditions that influence corrosion, without over-excavating. Shallow exposure (a few inches) may hide surface defects, while much deeper digging (twelve inches or more) isn’t required for routine soil-to-air checks and adds risk and cost. Therefore, six to twelve inches is the appropriate depth for this scenario.