Sizing Valve for Possible Tube Rupture

[quamaze]

Good day all-

I have a sizing question for a shell and tube heat exchanger. The only info I have is that the vessel had 150 psi stamped on the side of it. Can I assume that as MAWP? On my shell side I have steam entering at 25psi (pressure regulator 10-30) through a 1" line, and on my tube side I have mineral oil that is pumped in at a rate of 30gpm. In the event of tube rupture, should I size the relief valve for the entire volume of the vessel? How can I determine if the steam relief rate would be higher than the liquid relief rate?

Please help!

 

[quamaze]

I have also determined the max flow that can enter through regulator is 900pph and the volume of my vessel is 20ft^3.

How can I relate that to relieving rate?


Please help!

 

[CMA010]

I assume you want to calculate this in order to size a relief valve?

You need to retrieve the design pressure of the shell side and of the tube side. If these design pressures do not comply with the 2/3 or 10/13 rule tube rupture is a viable relief scenario, see API STD 521, § 5.19. I would not be able to tell you what the 150 psi stamp means, i'm only familiar with nameplates.

The relief load can be taken as twice the flow rate of the medium on the high pressure to the low pressure side through an orifice. The orifice size being the inner diameter of the tubes. See the following article for more information: "PRV sizing for exchanger tube rupture", Hydrocarbon Processing, February 1992

 

[quamaze]

Thank you so much for your reply