“We have several models created with Microprotol for which we saved the results.
Now we are using AutoPIPE Vessel to recalculate the same models, the results are different regarding the weight of nozzles (a decrease about 80%).
I haven’t noted changes regarding nozzle.
Did you change other data?
One change that may answer the discrepancy between the models is that the calculation of the weight of nozzle necks has been optimized in September 2012 (v188.8.131.52) to consider the intersection of the neck with the shell (height difference depending on the inclination and eccentricity of the nozzle).
Before the nozzle neck was considered as a cylinder of constant height.
When the Analysis was done and the report was created, I realize that supports are not calculated with EARTHQUAKE load case but only with WIND load cases for this model. However, it works in another model. Why?
Furthermore, it would seem to be an error in the calculation of yC: yC = m + E + m + H/2 in the edition of the results.Should be rather considered yC = m + E + m + (H - m) / 2
The development team reviewed the user's model and determined that the editing options are different:
In a data-set, the "Edition of the determinant only case" check-box is checked and in the other data set, it is not.
When the option is checked and the case of earthquake is not the determinant case, it is normal that this case is not be published in the note of calculation.
With regards about your calculation error mentioned, there would be the error in calculation of yC because there is no weld at the top of the sail.
We need to design conical skirts for some tall columns. During design of anchoring (as per GOST R51274-99.8) for column in Microprotal software we observed that, if half apex angle of the skirt exceeds seven degree ( 7°) Microprotol software gives a warning message as "Half-angle at skirt apex exceeds the critical value" in the output report.
1) What is the critical value of half angle at skirt apex considered by Microprotol software?2) Is it GOST or any other Russian code requirement ? If yes, please inform us the relevant clause/paragraph no. of the respective code wherein this requirement is specified. If no, please inform us the basis of this value.
There is nothing in GOST R51274-99.8 to limit the half apex angle of the skirt.
But this is a usual rule, this limitation exists in AD S3/1 4.2 and in CODAP C9.7.1. (French code) to avoid the increase of bending moment due to the horizontal component of the compressive load.
Note well: the message (#35) is a Warning not an Error since there is nothing in GOST.
The following error message appears in the output report:
The thickness of the neck of tubing is not sufficient according to UG - 45.
How to fix and avoid this issue.
In both cases the tolerance must be taken into account.
In the first case, the tolerance (as a value) is added to the corrosion (as usual in AutoPIPE Vessel), so this is the value Can = 4.558 mm which is used in accordance with paragraph UG-45.
In the second case the value obtained by the application of UG-45 does not take into account the tolerance% because it can only be applied when the required thickness is known, that's why tUG-45 value should be increased to take into account the tolerance of 12.5% (11.34 / 8.75 = 12.96 mm) and compared to the nominal value of the thickness of the nozzle neck (12.7 mm). Similarly this tolerance is applied to the required thickness under internal pressure trn (non-dimensioning in this case).
Where can I select to compute the stress in a vessel shell induced by the circumferential weld (ASME VIII UG-27(c)(2)) Because if I put in a joint efficiency in the box for circumferential weld, the program computes this as a longitudinal weld. I would like to see the required thickness for the longitudinal stresses.
According to the ASME VIII Div.1 the minimum thickness shall be the greater thickness as given by the circumferential stress UG-27(c)(1) or longitudinal stress (c)(2).The thickness due to the circumferential stress is always the greatest (see below) consequently APV uses only the first formula (NOTE: in Div.2 there is only one formula: circumferential stress).
To be strictly conform to the code, APV should print out the both formulas but this will not change the result.
A new enhancement has been logged:
Enhancement 184810:Report both wall thickness results from Circ. Stress and Long. Stress Eq.
I am designing EN code tubesheet, where do the terms l1, l1' and gamma (γ) come from?
The terms l1 and l1' in the image of the output report above refer to the lengths of the shell with different thickness adjacent to tubesheet.
Refer to Section 13.5.9 and formulae 13.5.9-1 and 13.5.9-3.
'γ' is the axial differential thermal expansion between tube and shell.
If the shell is of uniform thickness then the values of l1 and l1' are equal to 0 as shown in the report above.
Allowable stresses input by user for test conditions