How Do You Inspect a Tank?
Inspecting a tank, particularly a storage tank, involves a systematic process to ensure its structural integrity, identify potential issues, and maintain safe operation. Based on standard practices, a thorough tank inspection follows several key steps.
A comprehensive inspection often begins with preparation and moves through detailed examination of the exterior and interior.
-
Empty the Storage Tank:
- The first crucial step in many tank inspections is to safely empty its contents.
- Why it's important: Emptying allows for safe access to the tank's interior and exterior surfaces for a complete visual examination without obstruction. It also eliminates hazards associated with the stored material during the inspection process.
-
Visually Examine the Exterior:
- Once empty, the exterior of the tank needs careful visual scrutiny.
- Look closely for any signs of wear, damage, or degradation.
- Key indicators to watch for include:
- Cracking: Surface lines or splits in the material.
- Crazing: A network of fine cracks on the surface, often indicating material stress or aging.
- Brittle Appearance: Areas that look faded, stiff, or discolored, suggesting the material has lost flexibility or is degrading.
-
Check Critical Areas:
- Certain parts of a tank are more prone to stress or potential leakage points and require extra attention.
- Thoroughly inspect the areas around fittings. This includes nozzles, manways, vents, and any other points where pipes or equipment connect to the tank wall.
- Also, carefully examine areas where different portions of the tank converge into one another. These could be seams, welds (for metal tanks), or transitional areas in molded tanks where walls meet the bottom or roof. These points can experience higher stress loads.
-
Inspect the Interior of the Storage Tank:
- Access the interior (safely and following confined space procedures if necessary) to perform a visual inspection from the inside.
- Look for the same types of damage observed on the exterior – cracking, crazing, brittleness, but from the internal perspective.
- Check for signs of corrosion (in metal tanks), pitting, or liner damage if applicable.
- Ensure baffles, internal supports, or other components are intact and properly secured.
Why Regular Inspections Matter
Regular tank inspections are vital for preventing leaks, spills, and catastrophic failures. They help in:
- Identifying minor issues before they escalate into major problems.
- Ensuring compliance with regulatory requirements.
- Extending the operational lifespan of the tank.
- Protecting personnel, the environment, and assets.
Summary of Key Inspection Points
| Area Inspected | What to Look For | Importance |
|---|---|---|
| Exterior Surface | Cracking, Crazing, Brittle Appearance, Discoloration | Material integrity, signs of aging/stress |
| Around Fittings | Leaks, Cracks, Corrosion, Proper Seating | Potential leak points, stress concentration |
| Convergence Areas | Seams, Welds, Transitional Zones - Cracks, Integrity | High-stress areas, structural weak points |
| Interior Surface | Cracking, Crazing, Pitting, Corrosion, Liner Damage | Internal integrity, effects of stored material |
By following these steps, tank operators can perform effective inspections to maintain safety and reliability.
