Ans.
Seamless drawn pipes.
The diesel engine fuel injection piping is subjected to very
high pressure, in the range of about 1200bar. Also, there is sudden increase
and decrease of pressure which causes the fatigue in the material. Taking into
consideration these two things it is necessary that the material and the
manufacturing process of the piping should be such that it should be able to
withstand the high pressure and fatigue. It is also of prime importance, from
the point of view of safety of the ship and fire hazard, that the fuel pipe
should not get cracked under these high pressures. In order to achieve these
requirements, it is necessary to use fuel pump pipes made up of seamless, solid
drawn tubes.