API 9th Edition (para 7.5.6.2): Extended tubesheet for Bonnet type exchanger head

[gajwani]

As per para 7.5.2.4 of API 660 (9th Edition), Full diameter stationary tubesheet shall be provided with collar studs or tapped tubesheet holes for Removable tube bundle with bonnet head (TEMA type B).
However in our exchanger, we are providing test ring/ flanges for hydrotest. Please inform whether we can waive API 660 requirment for providing full diameter tubesheet.
Saurbh Gajwani
+91-9873732200

 

[SnTMan]

gajwani, if it is to be your exchanger, you can do anything you want. If you are building for a client who has imposed API 660, you would typically need permission to deviate.

Your proposal seems to meet the intent of the full diameter tubesheet, but be aware that when you drop the bonnet you have removed the seating force from the shell gasket. It may not seal when the exchanger is reassembled and would then need replaced.

Poor practice, IMO.

Regards,

Mike

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