CR4 - The Engineer's Place for News and Discussion ®


Previous in Forum: Alloy Steel 8620   Next in Forum: Pump Curve
Close
Close
Close
4 comments
Anonymous Poster #1

Tubesheet _Collar Bolt Design

01/06/2017 10:43 PM

Dear All

API 660 8th Edition, clause 7.6.2.4 stated "The tubesheet shall be designed to maintain the gasket seal through the use of collar studs or tapped tubesheet holes and allow hydrotesting of the shell side without the bonnet installed."

May I know what is your understanding on this clause? Is it means that the use of collar bolts is prohibited during hydrotest?

API 660 9th Edition did updated this clause to "The tubesheet design shall allow for hydrostatic testing of the shell side with the bonnet removed and all bolting installed."

Thanks in advance.

Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Guru

Join Date: Oct 2008
Posts: 39128
Good Answers: 1542
#1

Re: Tubesheet _Collar Bolt design

01/06/2017 11:12 PM

No.

Reply
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 19814
Good Answers: 741
#2

Re: Tubesheet _Collar Bolt design

01/07/2017 1:57 AM

It might be interesting to know the context and motivation of this question.

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Reply
Guru
Hobbies - CNC - New Member Hobbies - DIY Welding - New Member Engineering Fields - Electromechanical Engineering - New Member

Join Date: Aug 2007
Posts: 18230
Good Answers: 319
#3

Re: Tubesheet _Collar Bolt Design

01/07/2017 7:59 PM

No, it's just for testing the shell side, with the bonnet remove you can visually inspect if the are any leaks though the tube and the shell and the tube sheet to shell gasket.

the tube side test will be tested separately with the bonnet and without the shell for the same reason, In other words, see if the are any leaks in the tubes, bonnet and gasket.

This is similar for ASME U stamp testing for test, but the tubes need not be installed for ASME, and both the shell, and tubes would get stamped.

I'm sure it's the same reason for API.

__________________
phoenix911
Reply Score 1 for Good Answer
Member

Join Date: Sep 2011
Location: Delhi, India
Posts: 6
#4

Re: Tubesheet _Collar Bolt Design

02/14/2017 5:52 AM

Collar bolts are used where tubesheet employed is extended as a flange. Collar bolts (usually 25% bolts or min. 4 in no. are provided as collar bolts) serve many purposes like

1) it ensures that during disassembly of channel, the gasket between shell flange & tubesheet does not get disturbed. Otherwise bundle has to be removed completely to insert new gasket for shell flange - tubesheet bolted joint. Collar is designed for flange gasket seating condition only.

2) During hydro testing of shell side where channel/bonnet is not in place, tubesheet acts as a flange with the help of collar bolts i.e. test ring is not required in that case and assembly of channel is performed without disturbing tubesheet-shell flange joint. Tubesheet should then essentially be designed for hydro test design case, of course you can use higher allowable stresses in test case equal to 90%-95% of YP as your client spec allows.

__________________
pksingla11
Reply
Reply to Forum Thread 4 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Copy to Clipboard

Users who posted comments:

lyn (1); phoenix911 (1); pksingla11 (1); Tornado (1)

Previous in Forum: Alloy Steel 8620   Next in Forum: Pump Curve

Advertisement