Flash point is the minimum temperature that can oil has to be heated to produce sufficient volatile vapours capable of ignition when in contact with an open flame Under specified test conditions.
> All diesel fuels on ships must have flash point greater than 66 degree Celsius (According to solas minimum flash point us 60 degree celcius. )
> It is main fire hazard classification of oil
Closed Flash point :- It is the minimum temperature for enough flammable mixture to give a flash when a test lamp source of Ignition is introduced in a container.
It is measured in a Pensky -Martin Closed tester (container )where outside Atmosphere does not influence the oil vapours.
Open Flash point :- No lid on the container,no vapour is lost ,but temperature is sufficient to give a flash ,when a test temperature source of Ignition is introduced in open container.
It is approx. 15 degree celcius higher than closed flash point.
Test is carried in a Pensky -Martin or Abel tester