Verify Leak Tightness After Maintenance Work

Image © EPSC


When a flange or other equipment is closed, it can still leak, when hazardous chemicals are introduced.

When Important

  • After work where equipment and flanges have been opened.
  • Temperature change can influence bolt tension and create leakages.

Challenges in the Field

  • Competent people when bolting.
  • Verification competency or procedures are missing.

Options to Get it Right

  • Perform a leak test before introducing hazardous chemicals.
  • Leak test can be done:
    • by introducing a less hazardous gas and perform a pressure hold test;
    • put soap bubbles on all flanges that have been opened;
    • ultrasound measurements can detect leakages.
  • Develop criteria for acceptance of leak test results.
  • Develop a special procedure for the flange that was used in the leak-tightness test (the flange to be closed after the leak test).
  • Verify proper torqueing.
  • Validate and adjust bolt tension after heating-up the equipment.
  • Record Leak Test results.

This page only summarises the guidance – refer to the EPSC website for further information.

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