I had a rupture disk fail due to thermal expansion in a 6" dia CS aboveground pipeline.  How can I determine the pressure increase?

find the CTE (cubic) for the fluid, multiply by the appropriate temperature differential to find change in fluid volume with no pressure change.  Call this DVF.

Find the CTE for the pipe material, multiply by temp. difference, cube the result - this is the change in volume of the pipe with no pressure diff., call it DVP.

Calculate the dVol/dpressure for the pipe - requires knowledge of pipe stress equations.  Call this factor DVDPP.

Calculate the dVol/dpressure for the fluid - this is also known as the fluid's bulk modulus.  Call it DVDPF

The pressure is the common factor here, i.e. Ppipe = Pfluid.

So, calculate the pressure rise, plug it into the pipe equations to find the volume expansion of the pipe, subtract that number from the volume expansion of the fluid, and recompute the pressure rise in the fluid, use the new pressure to recalculate the pipe expansion....etc.

There is probably an algebraic solution too, but I don't have time to work it out for you.

Natural gasoline is in the line with 10 psi blocked-in.  Ambient temperatures were a low of 28 degrees F and a high of 54 degrees F.  Length of line is 1800 ft.  The rupture disk is designed to fail at 270 psi.  What I'm really looking for is if under these conditions, would thermal pressure increase enough to rupture the disk?

Natural gasoline is in the line with 10 psi blocked-in.  Ambient temperatures were a low of 28 degrees F and a high of 54 degrees F.  Length of line is 1800 ft.  The rupture disk is designed to fail at 270 psi.  What I'm really looking for is if under these conditions, would thermal pressure increase enough to rupture the disk?

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