Revision

Question 1

What are the safety concerns when a hydrocarbon is present in a storage tank?

Answer 1

Fire / explosion
Displaced breathing zone (less O2)
Contaminated breathing from the hydrocarbon evaporation.

Question 2

Welding a tank which was previously filled with oil, what safety precautions should be taken for the welder. Considering the layers as:
1) Before work starts
2) Whilst welding the exam
3) During the work
4) On completion

Answer 2

1) Making sure the tank is completely emptied / Iolation / Checking area is safe.
2) Briefing on alarms / Evacuation / permit to work
3) Making sure PEE is effective in work
4) Inspect area / recieve PTW / Remove sensors and notify control room that work is complete

Question 3

Listing protection layers structure (previously mentioned in HAZOP)

Answer 3

Process valve - PBCS
Operatore shutdown - Alarm
Active protection - bursting disc
Passive protection - Absorbent materials
Emergency response - Safe areas
Community emergency response - Plan with fire brigade