Tubesheet Design
Tubesheet Design
(OP)
Early appology if this has been discussed before; I did several searches but was unable to find anything relevant.
We have a customer who currently owns a shell & tube heat exchanger (TEMA NEN); he uses it more as a reactor vessel than a heat exchanger. He is looking to have his existing unit modified.
Currently it has 1-1/8" OD tubes. The owner wants new tube sheets and baffles installed, but he wants to use several different size tubes, ranging from 3/4" OD to 2" OD, with mostly 1" OD tubes (total of five different sizes). All sizes are standard condenser tube sizes.
Background: Design will be to Section VIII, Division I, unit will carry NBBI R stamp.
Just wanted to get some additional thoughts on how to go about calculating an appropriate tubesheet thickness. The existing unit was designed to Ed '04, A'05, and we know what the existing thickness is. We don't know what the tube-tubesheet attachment is, but we plan on double serrating every tube hole, and expanding and seal welding every tube.
We have a customer who currently owns a shell & tube heat exchanger (TEMA NEN); he uses it more as a reactor vessel than a heat exchanger. He is looking to have his existing unit modified.
Currently it has 1-1/8" OD tubes. The owner wants new tube sheets and baffles installed, but he wants to use several different size tubes, ranging from 3/4" OD to 2" OD, with mostly 1" OD tubes (total of five different sizes). All sizes are standard condenser tube sizes.
Background: Design will be to Section VIII, Division I, unit will carry NBBI R stamp.
Just wanted to get some additional thoughts on how to go about calculating an appropriate tubesheet thickness. The existing unit was designed to Ed '04, A'05, and we know what the existing thickness is. We don't know what the tube-tubesheet attachment is, but we plan on double serrating every tube hole, and expanding and seal welding every tube.
-TJ Orlowski





RE: Tubesheet Design
I think you are going to have to get an early buy-in from the AI for whatever you propose to do as well.
Tough problem:)
Regards,
Mike
RE: Tubesheet Design
Regards,
Mike
RE: Tubesheet Design
This will most likely be our initial approach. Each ligament will be greater than or equal to the ligament that would be present if all the tubes were the same (ie the ligament of any 2" tube hole would be .482 in any direction, even if all surrounding tube holes are smaller).
I plan on doing UHX calcs and wiping the dust off the TEMA calcs as well; luckily our AI remembers the couple of times that ASME scratched what they had come up with and told S&T fabricators to refer back to TEMA.
Thanks for the input.
-TJ Orlowski