Aux 2 Unit 14 Petrol, LPG, volatile fules and Fuel lockers Q5 Answer

  1. With reference to the storage of volatile fuels, describe the construction and placement requirements of the storage tanks for aviation fuel, including tank ventilation.(10)

Construction and Placement Requirements of Storage Tanks for Aviation Fuel (10 marks)

1. Location and placement (2 marks)

  • Aviation fuel storage tanks must be located on open deck or in a well-ventilated compartment, isolated from accommodation and machinery spaces.
  • Tanks should be as far as practicable from sources of heat, ignition, or electrical equipment.
  • The deck area around the tanks should be designed to contain and drain any spillage safely overboard, without entering enclosed spaces or bilges.

2. Tank construction (2 marks)

  • Tanks must be constructed of welded steel (or approved corrosion-resistant alloy) capable of withstanding design pressures and temperature variations.
  • The internal surface must be smooth, free from rough welds, and free of corrosion or scale, to avoid contamination of the fuel.
  • Non-sparking materials should be used for fittings and tools associated with the tank.

3. Corrosion protection (1 mark)

  • Tanks and associated pipework should be painted internally with fuel-resistant coatings or treated to prevent rust and contamination.
  • Bonding and earthing must be provided to prevent static electricity build-up during refuelling and discharge operations.

4. Ventilation and venting arrangements (3 marks)

  • Tanks must be fitted with a dedicated venting system to prevent pressure build-up or vacuum formation as fuel levels change.
  • Vent outlets should:
    • Terminate in a safe, open-air position, well clear of ignition sources and accommodation openings.
    • Be fitted with a flame arrester or wire gauze screen to prevent flashback into the tank.
    • Be designed to drain condensed vapour or rainwater back to the tank or to a safe catchment.
  • Vent pipes should have sufficient diameter to allow free breathing during filling and emptying operations.

5. Isolation and drainage (1 mark)

  • Tanks must be fitted with shut-off valves and drain connections at the lowest point for removal of water or sediment.
  • Drains should discharge to a closed, dedicated container—never directly overboard.

6. Access and inspection (1 mark)

  • Tanks should have inspection and cleaning openings (manholes) fitted with gas-tight covers.
  • Access should allow regular inspection, sampling, and maintenance without risk of contamination.

7. Identification and safety signage (1 mark)

  • Tanks must be clearly marked “Aviation Fuel – Highly Flammable”, with appropriate warning notices prohibiting smoking or naked lights in the area.
  • A fire extinguisher station or firefighting equipment must be located nearby, readily accessible at all times.