Tubesheet/Separator Plate with nozzle

[bayardwv]

We fabricate pressure vessels that are used with proprietary internal parts used for filtration.

These often use a separator plate sandwiched between 2 body flanges. This plate has openings that filtration elements are connected to and the only pressure the separator plate is subjected to is Differential pressure between the Dirty and Clean sides that builds up as the filter collects dirt. This is not considered to be a code part of the vessel and the only calculation performed for the separator plate is one to determine the min required thickness needed to withstand the Differential pressure.

Finally...here's my question.

Our Customer has asked us to provide a replacement separator plate, however they want to add a flanged drain connection projecting out along the peripheral edge. Does the tube sheet now need to be a code part with a U-partial stamp and data report?

 

[SnTMan]

bayardwv, if I understand the construction: I'd say yes. Wouldn't call it a tubesheet, though.

There would be some rim thickness needed to contain the internal pressure, perhaps as a shell element. The drain connection may need to meet reinforcment rules.

Can't see anything else to it.

Regards,

Mike

 

[Duwe6]

Concur - it'll need a stamp as a 'Partial'.

 

[bayardwv]

Thank you both. I was thinking it needed to be but wanted some other opinions.

Now I'm trying to figure out how to test the nozzle weld without having to perform a hydro test.
The only way I can think to do a hydro is to weld a coupling over the nozzle hole on the top side of the separator plate and close the flanged nozzle off with a blind flange. Then Tap the blind flange for a pressure port and install a pressure gage on the the coupling, and then grind off the hydro coupling after successful hydro. Any other ideas?

 

[Duwe6]

Exactly how I would hydro it. Perform PT/MT on the removal area if the entire hydro fitting weld is removed. If the fitting is cut off 'high', leaving the weld behind, then that weld has already been hydro'd and is acceptable as a permanent item. Also, check with the customer; there may be some type of fitting that maintenance/operators would like left behind. If so, use that and give it to them "for free $$"

 

[sathikn87]

tube sheet need stamp?? But it must be an internal part just to separate upper and lower plenum & will only be subjected to applied pressure..

 

[SnTMan]

Plate will not need stamped if furnished a part of a stamped vessel. Stamped as part if furnised as a part.

Regards,

Mike

 

[sanshu1111]

Bayardwv,
Isn't the tube plate design and construction remain the same even with the drain connection on it (except for the drain connection)? This plate will still see only the differential pressure within the filter housing.

A sketch will be helpful to understand the construction of drain nozzle but I guess that the drain nozzle is connected to the tube plate and taken out from the vessel through the shell or head section. Reinforcement calculation shall be therefore required for the shell/ head where this drain nozzle is connected. If I understand it correctly, vessel modification is also required for this drain nozzle.