how to check peaking and plumbness as per API 650

Introduction

This tutorial guides you through the process of checking peaking and plumbness in storage tanks, following the guidelines set by API 650. Ensuring that tanks are plumb and not peaked is crucial for safety, structural integrity, and operational efficiency. This guide will provide you with clear, actionable steps to perform these checks effectively.

Step 1: Understanding Peaking and Plumbness

• Peaking refers to the condition where the top of the tank is not level, causing a dome-like appearance.
• Plumbness indicates whether the vertical structure of the tank is perfectly upright.

Practical Advice

• Familiarize yourself with API 650 standards to understand the acceptable tolerances for both peaking and plumbness.

Step 2: Gathering Necessary Tools

Before starting your checks, ensure you have the following tools:

• Leveling instrument (e.g., laser level or water level)
• Measuring tape
• Plumb bob or plumb line
• Notepad for recording measurements

Practical Advice

• Ensure all tools are calibrated and in good working condition for accurate readings.

Step 3: Measuring Plumbness

1. Select Reference Points: Choose a point on the tank’s base as a reference.
2. Use a Plumb Bob:
   • Suspend the plumb bob from the reference point.
   • Measure the distance from the bob to the tank's vertical surface at multiple points around the tank.
3. Record Measurements:
   • Note any deviations from the reference point.
   • Compare measurements to determine if the tank is within acceptable plumbness limits as per API 650.

Common Pitfalls to Avoid

• Ensure the plumb bob does not sway during measurement for accurate results.

Step 4: Checking for Peaking

1. Identify the Highest Point:
   • Use a leveling instrument to find the highest point on the tank top.
2. Measure from the Highest Point:
   • Identify the lowest point on the tank top.
   • Measure the difference in height between the highest and lowest points.
3. Evaluate the Results:
   • Determine if the height difference exceeds the API 650 specified limits for peaking.

Practical Advice

• Conduct measurements at various points to get a comprehensive understanding of the tank’s condition.

Step 5: Documenting Findings

• Create a detailed report of your findings, including:
  • Measurements of plumbness and peaking.
  • Any corrective actions needed.
  • Date and time of the inspection.

Practical Advice

• Regular documentation helps track changes over time and supports maintenance decisions.

Conclusion

Checking for peaking and plumbness is critical for the integrity of storage tanks. By following the steps outlined in this tutorial, you can ensure that your tanks meet the API 650 standards. Remember to regularly conduct these checks and document your findings for ongoing maintenance and safety. Consider scheduling periodic inspections to proactively address any potential issues.