Shell & Tube exchanger pressure rule
Shell & Tube exchanger pressure rule
(OP)
Is there any requirement per TEMA code on the maximum difference or ratio between the shell side and tube side design pressure? Can the shell side pressure be very high as compared to the tube side pressure? and vice verca? What is the 2/3 rule? I heard of it, but could not find it in TEMA code.
If you think about it, if the shell side pressure is very high as compared to the tube side pressure, the tubes will need to be designed for the high external pressure in the respective load case. If the shell side pressure is too high, will it make tubes too thick?
If you think about it, if the shell side pressure is very high as compared to the tube side pressure, the tubes will need to be designed for the high external pressure in the respective load case. If the shell side pressure is too high, will it make tubes too thick?





RE: Shell & Tube exchanger pressure rule
Standard practice is keep high pressure on tube side and not shell side. I have never seen exchanger designed with very high pressure on shell side. Keeping high pressure on shell side would be very uneconomical.
RE: Shell & Tube exchanger pressure rule
100 X 1.5 = 150, 150 x 2/3 = 100.
Of course it should now be the "10/13" rule since hydrotest is 1.3x.
As for extrnal pressure on tubes, you absolutely have to watch this as cases can occur where the shell side pressure and temp exceed the allowable for the tube, for example, thinwall stainless at high temps. Sometimes the party specifying the exchanger does not do this calculation. You can then go to a thicker tubewall, derate the tube design temp, or do a diff pressure design. Don't get me started about u-bends.
Hope you find this useful.
Mike
RE: Shell & Tube exchanger pressure rule
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