← MeoMock / Written exams
Class 2 (2nd Engineer) MEP 📅 Feb 2018

Exam Question

(a) Describe the events leading to a crankcase explosion

(b) State how overheating might be indicated other than by a mist detector.

(c) State how severity of a crankcase explosion is limited.

(d) Emission of flame has in the past caused severe burns to personnel present during a crankcase explosion. Despite the addition flame traps. Discuss the procedure in the invent of over heating being indicated.

Reference Answer

(a) Sequence of events leading to crankcase explosion.
If a hotspot exists in crankcase, some lube oil will come in contact with it will be vaporised.
The vapour will circulate to cooler parts of the crankcase and condense to form a white oil mist
The oil droplets in this white mist are very small. If this oil mist circulate back to the hotspot in such concentration (with typical particle sizes of around 0.5 to 5 microns in diameter, density between 30 to 50 mg/L (milligrams per litre)), it will be ignited and a primary explosion will occur.

Full answer on MeoMock — surveyor-grade reference answers for 7,000+ written exam questions.

View plans Browse library

← Browse more questions

Prepare on Android — MeoMock on Google Play