Where should the telltale hole be located on the manhole reinforcing plate?

• A. Along the top edge
• B. Horizontal Centerline
• C. Bottom edge
• D. Near the weld seam

Answer: (B)

The telltale hole should be located at the horizontal centerline of the manhole reinforcing plate. Positioning the telltale hole at this location is critical because it serves to indicate potential leakage or the presence of moisture accumulating in the area. When located at the horizontal centerline, it effectively allows for the most accurate detection of fluid or condensation that may gather as a result of leaks around the manhole.

If the hole were placed at the bottom edge, it might not provide an early warning of leaks, as any accumulation below the centerline may escape notice until significant fluid build-up occurs. Similarly, positioning the hole along the top edge would similarly limit its effectiveness in capturing important leakage signs. The placement near the weld seam may also lead to misleading results, as this area could accumulate debris or be prone to biological growth, which could obstruct the hole or misdirect the indication of moisture levels.

By ensuring that the telltale hole is correctly placed along the horizontal centerline, operators can maintain better monitoring of the integrity of the manhole and, by extension, the tank's safety and environmental compliance.