This heater is applied to heating the fuel oil and lube oil inpower unit of marine and oil in other industries. Its heatingmedium is vapour or hot water. If the medium is vapour, its designpressure is no more than 0.98 Mpa and design temperature is no morethan 179.8???; If the medium is hot water, its design pressure isno more than 2.5 Mpa and design temperature is no more than 150???.Its heated medium is fuel oil or lube oil. Its practical workingparameter is subject to the technical agreement or order. Thisheater is also applied to heating the industrial lube oil(viscosityof N221-N150) in oil circular systems of machines for metallurgy,mine, etc..