Nozzle Reinforcement - Small nozzles in area of reinforcement of the larger nozzle

[a6gupta]

Good Day,
[ul]
[li]Vessel (Cone) - 3/4" Thk, SA 516-70 (N), Cone half apex angle ~8°. Main nozzle - ~69" ID, ~82" OD (Heavy Barrel); SA-350 LF-2,CL1. Nozzle has an internal projecting of ~ 1 1/8".[/li]
[li]There are a few small-bore nozzles (NPS 2) ~7'-9' from the edge of the Nozzle OD.[/li]
[li]Pressure is ~100 psig; no external pressure case.[/li]
[li]To make the calculation work, i limited the radial limit of shell reinforcement (A1) to be a bit away from the other NPS 2 nozzles. However, the weld size is ending up to be ~1" (fillet weld size for both the upper, and the lower weld).[/li]
[/ul]

[ol 1]
[li]Question1- Is that thick a weld a problem in general? Does it result in a requirement for PWHT?[/li]
[li]Question2- Is there any way, i can make my calculation work by going the full extent of shell area of reinforcement? Perhaps by subtracting the reinforcement area required for the small-bore nozzles.[/li]
[/ol]
Thanks for your help.
regards
GA

 

[davefitz]

Also, one can consider "nozzle reinforcement" of the 2" NPS nozzle- if those are specified as sched XXS, perhaps there is inherent reinforcement with that approach.

"Nobody expects the Spanish Inquisition! "

 

[doct9960]

a6gupta,

Are the 2" nozzles welded on the vessel cone or on the 6.5" thk. main nozzle?
What is the orientation of the 2" nozzles? Radial or hillside?
Are they LWN flanges?
What is the center to center distance of the 2" nozzles?

I suggest you post a sketch so forum members can get a better understanding of your design.

 

[a6gupta]

Good Day Doct9960,
The 2" nozzles are on the vessel cone. They are 7" to 9" away from the cutout diameter. These nozzles are horizontal (hillside). These are pipe neck nozzle Sch 80.
The main nozzle is radial (i.e. normal to the cone surface). This nozzle uses a forging (Heavy barrel type).
The 2" nozzles are approximately located on a circle concentric to the main nozzle, at a Pitch circle diameter of ~91", and located at approx 2 o'clock, 4 o'clock, 8 o'clock, and 10 o'clock positions.
Sorry, i would not be able to upload a sketch until tomorrow. Thought of giving an idea to the group in the meantime.
regards
GA

 

[doct9960]

While you're at it, you might as well mention the size of the cone (large od, small od) and the location of the main nozzle from one of the edges of the cone. On Question 2, what's stopping you from using the full extent of shell area of reinforcement?

 

[GenB]

Heavy fillets are typical in a heavy plate and nozzle. If you want to avoid p.w.h.t. your option may be reinforcing pad. Small nozzles around may not be an issue if >6 in. away but if in the reinforcing pass you may have to calculate the staggering as ligaments and get the efficiency. Which will not be in your favor. Check ligament calcs samples in the Appendixes. Excess vessel material can be used for reinforcing the nozzle it helps a little but not much. Genblr