best sequence for tube rolling on tubesheet
best sequence for tube rolling on tubesheet
(OP)
What is the best sequence- preferred order of rolling or strength welding of tubes on a tubesheet layout in a shell and tube heat exchanger? I'm interested in knowing how to determine the order and how it affects the tubesheet warping or is it just based on convenience of fabrication?





RE: best sequence for tube rolling on tubesheet
Suggest welding first, then rolling. Note, when seal weld only, you should roll the tube first.
This topic has been a very disputed in past, check out the previous posts.
Cheers,
gr2vessels
RE: best sequence for tube rolling on tubesheet
RE: best sequence for tube rolling on tubesheet
RE: best sequence for tube rolling on tubesheet
If it is a tubesheet about 1 meter in diameter, not so much.
Gr2vessels has made some good points about when to roll and when to weld. I'd add that you may want to consider a contact roll before welding. This isn't a hard roll, just a roll that barely contacts the wall of the tubesheet hole and centers the tube in the hole. Then after welding do the hard roll.
rmw
RE: best sequence for tube rolling on tubesheet
RE: best sequence for tube rolling on tubesheet
What is important is to not miss any tubes.
Regards,
Mike
RE: best sequence for tube rolling on tubesheet
RE: best sequence for tube rolling on tubesheet
The number of tubes in each will depend on your QA and tooling maintenance procedures. I have seen these drawn on the tubesheet with marking chalk while the tubes are being installed.
Often you see people roll 50-100 tubes (depending on size of unit) between quality checks and expander replacement. While the operator is changing expanders and verifying torque setting the QA guy is taking his check dimensions. Then of course the used expander is cleaned and inspected and put back into rotation.
This process allows you to keep track of smaller groups of tubes at a time and to skip around the tubesheet with less risk of missing tubes.
= = = = = = = = = = = = = = = = = = = =
Plymouth Tube
RE: best sequence for tube rolling on tubesheet