Purpose of Trepanning in Shell & Tube Heat Exchangers?

[Guest102023]

As stated in header.
Is it just for facility of welding, or is there a design rationale involved?

"If you don't have time to do the job right the first time, when are you going to find time to repair it?"

 

[SnTMan]

brimstoner, can't say I am familiar with use of the term. So far as I know, it refers to the process of forming a hole by cutting out a slug, kinda like a holesaw.

What's the context?

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[Guest102023]

Sorry for being incomplete. It is the tube to tubesheet joint I am interested in, with the tubesheet having grooves machined around the tube holes.

"If you don't have time to do the job right the first time, when are you going to find time to repair it?"

 

[SnTMan]

Well, I have seen the TS J-grooved around the tube hole for a welded joint, as well as bevelled. I don't know how they formed the groove, I assume a second operation after drilling.

Not really a trepan, I guess.

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[desertfox]

Hi brimstoner

Its used for large holes where solid drilling would be to power consuming see this link.

http://www.sandvik.coromant.com/en-...dicated_methods/trepanning/pages/default.aspx

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

 

[Guest102023]

Fox,

Not what I am thinking of. Picture a moat around the tube hole on the tubesheet face.

"If you don't have time to do the job right the first time, when are you going to find time to repair it?"

 

[desertfox]

brimstoner

See pages marked 3,4,5 and 6on the actual sheets

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

 

[EdStainless]

When they do that the "hub or stub" that is left is the exact same dimensions as the tubes.
The tubes are then but welded to the stubs, from the tube ID, without filler, in one pass.
It lets you join tubes to tubesheets without any crevices on either side.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

 

[DBreyer]

brimstoner,

I think it is used for in bore welded tube to tubesheet connections, like seen here:

http://www.knm-group.com/images/products&services/09/04-lhpressure04.jpg

By machining the grove an orbital but weld can be made.
This is sometimes used for high pressure quench coolers.

Daniel Breyer
Inspection Engineer

http://lnkd.in/dFcQA-w