- Devices such as crank case relief door, flame trap, crankcase oil mist detector CO2 drenching system are fitted to crank case for prevention and protection from crank case explosion.
- Crank case doors are robust in construction and non return relief valves are fitted to crank case of each cylinder.
- The total clear area through the relief valves is normally greater than 9.13 cm3/m3 of gross crank case volume
- Crank case relief door's outlets are so guarded that personnel are protected from flame discharge in case of an explosion
- Lubricating oil drain pipes from engine sump to drain tank should extend to below the working oil level in the tank
- Drain and vent pipes in multi cylinder engine are arranged so that the flame of an explosion cannot pass from one cylinder to another