Add Another Nozzle at the Pipe of a Nozzle? (ASME Pressure Vessel)

Yes you can. It is supported by ASME. PVelite also provide tool to add nozzle upon a nozzle.

Hope it helps.

Hi Anny,

Do you know in which part of ASME Section VIII Div 1 mention about this? Is it inside UG or UW? And which tool of PV-Elite are you mention? Is it CodeCalc?

Please open the nozzle dialog box in Pvelite. Enter the details of an 8" Nozzle ''A' then click "add new nozzle". Here you enter the details of Nozzle 'B' which is of 2". Now, check the box saying "Is this nozzle connected to another nozzle" then click the "Parent Nozzle" box. A list of nozzles will appear, click the nozzle 'A' and check "enter the distance from shell surface". Enter this value and you are done.

Hope it clarifies

Hi Anny, thanks for your explanation. By the way, do you know in which part of ASME Section VIII Div 1 mention about this? Thanks.

Having asked the question several times and received the same answer, it would appear not.

Please obtain a copy of the standard and read it locally.

The concept of 'scope' of ASME VIII-1 is important. It is basically defined in U-1(e) - anything closer than the first circumferential joint in a nozzle or the first flanged joint in a nozzle is within the 'scope' of ASME VIII-1. I believe that the locations described in U-1(e) should be interpreted as 'no closer than' features rather than 'no further than' features. The 'no closer than' interpretation prevents you from defining the 'scope' of your vessel to end before the nozzle opening and you from justifying a sub-standard opening reinforcement. The 'no closer than' interpretation also allows nozzles on nozzles, etc.

Once you are within the scope of ASME VIII-1, the Code does not prescribe any arrangement of features. It regulates things by geometry: if it looks like a nozzle, it is to be calculated as a nozzle, regardless of name or purpose. (A small exception to this is how inspection openings are treated.) The shape of your vessel may be completely defined by function and may be analyzed as an endless series of standard Code details. It only ends where it is required to mate up with other equipment - see U-1(e), again.

Look at UW-3. In this section the Code uses a concept of 'communicating chamber' that they define in note 66 as intersecting heads and shells and that form an integral part of the pressure boundary. The primary nozzle in a nozzle on nozzle situation is one of these.

U1(e)1(a).

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First circumferential weld(butt weld or girth weld).It may be situated in between a nozzle from vessel to external pipe.In this case, the first external butt weld also shall be considered in the scope of ASME Sec VIII Div-1