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