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LOCAL STRESS IN SHELL DUE TO FORCE ON NOZZLE

LOCAL STRESS IN SHELL DUE TO FORCE ON NOZZLE

LOCAL STRESS IN SHELL DUE TO FORCE ON NOZZLE

(OP)
I know I can find here experienced enginners who are willing to share their knowledges. My problem is probably futile but I nevere managed to clarify everything in my head on this matter. Let's imagine I have a size 500mm manhole, on top of a horizontal vessel with diameter 2000mm, 10mm thick. On the manhole blind flange I have to put a pump with a weight of 500 kg. I have 0.5 MPa in the vessel. Vessel material... ASTM A516.

How can I evaluate if the shell can handle the weight of the pump ?
I searched the ASME VIII, tried to find WRC 107 & 297, I read some articles, I even got the spreadsheets from http://www.xcalcs.com/ and tried them but I still cannot be sure if I understood well.
Please, can someone take 10 minutes or more of his time and send me some directions ? Please don't imagine I will feel hurt if the explanations are too scholastic or too "stupid proof". I am quite young and living in Romania so I will take the liberty to consider these my excuses.

Thanks and Best regards,
Doru
doru7171@hotpop.com

RE: LOCAL STRESS IN SHELL DUE TO FORCE ON NOZZLE

WRC-107 is part of vessel design programs such as Compress and PV-Elite. Its very simple to determine max nozzle loads using this software. I did a quick check on the info you provided and calculated max radial load (+P) on nozzle as 11600 kg. This is based on grade 70 material, 0 corrosion allowance, no repad and design temp < 260 C. There may be other loads to consider, such as pump operation, and piping loads.
 
Regards  

RE: LOCAL STRESS IN SHELL DUE TO FORCE ON NOZZLE

(OP)
Thanks for your post ! I know about the existence of that software but unfortunately I do not have it. I had an evaluation copy (demo) and it let me a pleasant impression but unfortunately that software does not fit in my employer purchase list. This is why I tried to get a more "academical" approach. That is: "hand-made" calculations or free software/spreadsheets. Can someone help me in that ideea ?

RE: LOCAL STRESS IN SHELL DUE TO FORCE ON NOZZLE

Team Members and DORU (Mechanical)

Humm, FE-PIPE and or Nozzle Pro.

Due a search on Google WRC 107. you will fine some engineering spreed sheet.

Leonard@thill.biz
www.thill.biz

RE: LOCAL STRESS IN SHELL DUE TO FORCE ON NOZZLE

You are looking for academical answers! good luck.
You are puting a crushing load on the vessel and if the vessel is already designed/mfd. you can not use the cover plate/pad to hold a 3/4ton. If you are to design the vessel, you have to provide means to hold the load, whether increasing the t of the shell plates or stiffeners calculated accordinglyl; even the nozzle/pad/coverplate sizing has to be designed to hold the loads.
ER

RE: LOCAL STRESS IN SHELL DUE TO FORCE ON NOZZLE

...say 1.1/4 ton load
ER

RE: LOCAL STRESS IN SHELL DUE TO FORCE ON NOZZLE

(OP)
I said "academical" as a joke, of course... Anyway, thanks for all the tips.
I searched on google but dind't show up too many things.

RE: LOCAL STRESS IN SHELL DUE TO FORCE ON NOZZLE

While I've never done it myself, you can do a WRC107 evaluation by hand.  I've heard from older guys of having to do so back in the "good old days"

Edward L. Klein
Pipe Stress Engineer
Houston, Texas

All opinions expressed here are my own and not my company's.

RE: LOCAL STRESS IN SHELL DUE TO FORCE ON NOZZLE

(OP)
Please do not understand me wrong: I am doing sometimes calculations "by hand" due to the fact that I do not have the software !! I love computers and I would love to have all the discipline software in my computer.
The reason why I keep trying to understand the algorithms is for me to be able to build my own spreadsheets. As far as my company doesn't invest in software and I am requested for fast results, do you think I have another choice ?

RE: LOCAL STRESS IN SHELL DUE TO FORCE ON NOZZLE

Use Bednar's "Pressure Vessel Handbook" if you're doing it by hand.  Basically, it's WRC107/297 simplified [unless you get paid by the hour ]

RE: LOCAL STRESS IN SHELL DUE TO FORCE ON NOZZLE

(OP)
Do you know where I can find a pdf with that book ? Or any handbook for Pressure Vessels ??

RE: LOCAL STRESS IN SHELL DUE TO FORCE ON NOZZLE

Doru;
Bednar has a simplified formula for a point load on a vessel

stress in vessel =
        
      1.75*((R*t)^.5)*(P/L)/t^2

for your case;
R= vessel radius = 1000mm  (39.37")
t= thickness = 10mm  (0.394")
P = point load = 500kg  (1,102lbs)
L = Pi*diameter of nozzle = Pi*500=1571  (Pi*19.865 = 61.84)

stress in the vessel due to point load
      = 5455 pa   (791 psi)

RE: LOCAL STRESS IN SHELL DUE TO FORCE ON NOZZLE

Try BS5500
Regards
athomas236

RE: LOCAL STRESS IN SHELL DUE TO FORCE ON NOZZLE

To every one,
I do not think is a good idea of some one breaking the law in providing any information/copies of any program/software.
Doru: can you stop.
ER

RE: LOCAL STRESS IN SHELL DUE TO FORCE ON NOZZLE

(OP)
It was not my intention to break the law or to make someone else do it.
Stop.

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