(a) State FOUR possible contaminants that may be present in marine gas oil.(4)
(b) Describe a means of dealing with THREE of the contaminants listed in part (a).(6)
Marine Gas Oil – Contaminants
(a) Four possible contaminants (4 marks)
- Water (from condensation, leaks, or poor handling).
- Microbiological organisms/sludge (bacteria, fungi).
- Solid particles (rust, dirt, sand, or scale).
- Other oils/chemical residues (mixing with incompatible products during transport/storage).
(b) Means of dealing with three contaminants (6 marks)
- Water contamination
- Remove by draining tank bottoms, centrifuging, or fuel polishing.
- Microbiological growth
- Treat with biocides and additives, clean tanks, and polish the fuel to remove sludge.
- Solid particles
- Remove using strainers, duplex filters, and centrifugal purification before fuel reaches engines.
(If other oils/chemical residues are mentioned: return to supplier if out of spec; onboard, use segregation and blending controls.)