Technical - Change in Pipe

What was the starting temperature?

What is the material of the pipe?

What is the course subject?

<...put the pipe in a liquid whose temperature is 95" celsius what will happen to pipe...>

If the pipe started at a different temperature it will change length and diameter. By how much depends upon the volume of the vapour space inside it, the difference between the coefficients of volumetric expansion of the pipe material and the liquid inside it, the shape of the phase diagram for the material inside it, the effectiveness of the plug that seals it, the local barometric pressure, the depth to which the assembly is immersed and the density of the liquid in which it is immersed.

If the pipe started at the same temperature as this liquid, then nothing will happen.

Why is <...diesel...> of any relevance?

It depends on the difference between the coefficients of thermal expansion for steel versus diesel fuel.

If the diesel CTE is less, a partial vacuum will form inside the pipe as the assembly heats. The pipe is plenty strong enough to resist this force, so a bit of the diesel inside will boil.

If the diesel CTE is greater, the hydrostatic expansion will rupture the weakest link, which is probably the joint between the plug and the pipe.