Insert plates

[MANS1987]

Dear Experts,

I'm designing a pressure vessel (U stamp) that contains insert plate instead of reinforcing pads.
It is my first time that I use this kind of reinforcement.
My inquiry is about the method of mounting on the pressure vessel and which method of design shall i follow?

Thanks in advance.

 

[SnTMan]

MANS1987, you do know insert plates are butt-welded to the vessel don't you?

For nozzle reinforcing follow UG-37, see also Fig UG-40 (f),(g),(h) and also Fig. UW-16.1 (f-x).

Note these figs show integral nozzles, but I suppose it need not be. However the reason insert plates would generally be chosen is to avoid non-radiographable corner joints. Best study your specs closely.

Regards,

Mike

 

[MANS1987]

Thank you SnTMan for your prompt response, i know that insert plate are butt-welded.
But what i m asking about is not the integral nozzle configuration, i'm talking about the calculation of the thickness of this insert plate. how it will be calculated?? it's like the reinforcing plate calculation ( By Area replacement?? ASME cover like this issue??

 

[SnTMan]

MANS1987, in UG-37, it is treated as a pad would be, that is, part of the neck is considered as a reinforcing element. See the figures in UG-40 to establish dimensions of the element, especially thicnkess te.

Regards,

Mike

 

[jte]

MANS1987-

Simply put, if you are comfortable designing re-pads then you are used to calculating A1 (area available in shell) and A5 (area added in reinforcing element) per UG-37. From a UG-37 design perspective, all that happens when you are designing an insert plate is that you eliminate A5 and increase A1. So for a design procedure, you could design a repad, then take the OD of the repad and use that for determining the diameter of an insert plate. The thickness will be the nominal shell plate thickness plus the thickness of the imaginary repad. Don't forget to allow for a 3:1 taper for the insert plate to shell transition. The insert plate will likely be rectangular with rounded corners. That's fine, just be sure that the dimensions are larger than the OD of the imaginary repad.

Taking it a step further - adding a bit of complexity but potentially reducing steel weight, with an insert plate (and heavy wall nozzle if applicable), you are eligible to use the F factor in Fig. UG-37.1 to reduce the area required in the plane of the circumferential joints. Put another way, for a radial nozzle in a vertical vessel, the insert plate's horizontal dimension could be reduced. Most vessel designers have never taken advantage of this, and most clients would never know it exists. So no problem using F=1 (that's conservative) but the option exists.

 

[MANS1987]

Thank you very much jte and SnTMan for your help

Regards