Thanks TGS4,
Actually I should put my query properly, which I am doing now
I have made WRC-107 calculations of one nozzle using one Pressure Vessel Design Software. The software is comparing the calculated Pl+Pb+Q stress with the allowable stress which is based on average at Design temperature &...
Thanks DSB123 & TGS4
1) I am not able get the definition of "Operational Cycle" from code or any other source.
How Operational cycle can be defined in terms of Pressure and Temperature in the vessel?
2) If definition of "Operational Cycle" is independent of P or T, then the lowest temperature...
As per Cl. 5.5.6.1.d of ASME Sec. VIII Div 2,
"The allowable limit on the primary plus secondary stress range, Sps, is computed as the larger of the quantities shown below.
1) Three times the average of the S values for the material at the HIGHEST & LOWEST temperatures during the operational...
"Because the total stress which FEA shows is a sum of the bending stress and the membrane stress. But I would like to know how much is the membrane stress."
From FEA you can get membrane stress by displaying reults at the mid plane of shell elements. In ANSYS you can get it from...
The Loadings Clause of UG-22(e) mentions that "cyclic and dynamic reactions due to pressure or thermal
variations, or from equipment mounted on a vessel,
and mechanical loadings" shall be considered while designing the vessel.
Which means (by default) AI needs to check the design of this...
Only one line reply can not do. Tell your client to substantiate his claim by mentioning the list of equipment along with project, customer, mfg year etc. I suggest you to independently verify if these equipment really exist & are working properly. Take everything in writing from your client...
I have never seen tubes going beyond/on the groove diameter. It would not be good practice since stress patterns of Tube-Tubesheet joint & Relief groove would interfere giving stress levels higher.
1)You can ask client to show if they have done any similar design in past which is working...
sanshu1111,
It is not always true that nozzle is most stressed part in Heat Exchanger. The reason behind vendor being reluctant is the complexity and time involved in the fatigue analysis. I feel that, for this type of analysis it would take around 15 days for the Analysis+Report. So just find...
JStephen,
Following clauses from ASME Sec VIII Div.2 would help you to find allowable compressive stress & stress occuring.
4.3.10.2 Stress Calcuation for Head with Pressure & External Loads (Refer the point-d also.)
4.4.12.4 Allowable compressive stresses
BPVFEA
I will tell you how I do it for Pressure Vessels
1) If you are interested in getting stress of skirt & skirt to shell junction. Then Model Skirt, Dish End & Some part of first shell course. (length of shell course shall be more than 2.5 SQRT(R*T).
2) From seperate software (PVELite, COPMRESS...
I have done such analysis and not faced such problem
Make sure that,
1) UX is fixed somewhere (as per requirement of your problem & if it not axi-symmetric)
2) UY is fixed somewhere (as per requirement of your problem)
3) Coefficient of expansion ALPX is defined in material properties. It can be...
If you are not able find design rules, you can design it by FEA. Stress Analysis of one such flange is explained in following PVP paper.
http://www.peesi.com/Final-Paper-Large-Rectangular-Flange.pdf
(Thanks to Mr. Bharat Batra of Pressure Equipment Engineering Services, Inc)
That's great!
Elastic Plastic FEA has been paid little attenstion. I will create a new post for Elastic Plastic FEA. I will post my understanding as well as doubts. Let's learn & improve throgh discussion.
Regards
BPVFEA
Thank you TGS for the corrections. Some points I agree with you and some points I have different opinion. I am rewriting my explanation.
In my opinion,
1) It is irrelevant if piping load coming on nozzle is Mechanical or thermal. Finally it is the load acting on nozzle.
2) Under any of these...
Check if you can reduce the Design Temperature of bolts from following Clause Defined in Piping code B31.1.
"For fluid temperatures above 65C, the metal design temperature of uninsulated pipe and components shall be taken as 95% of the fluid temperature, except flanges, lap joint flanges and...
