1.1. Apply PTW procedure
2.2. Ventilation and purging for 24 hrs (min 12 hrs)
3.3. Use oxygen analyser before entry
4.4. Carry out a bag of necessary tool
5.5. Enter the boiler with your head first ( vertical boiler: enter with leg first)
6.6. Remember to open top manhole first then follow up with bottom manhole cover (to prevent hot air to hitting you)
