Problem:

The following screen appears when entering in a Inside diameter value in AutoPIPE's Flange Analysis software:

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Bolts*
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The value cannot be greater than flange outside diam. minus bolt hole diam.
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OK
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Why and how to avoid it?

Solution:

This message would appear when trying to manually insert a user defined value into the Bolt Circle Diameter field on the Bolt's tab of the Flange analysis dialog. 

In most cases the message indicates exactly what needs to be evaluated:

The value (13") cannot be greater than flange outside diam. minus bolt hole diam. 

Need to find the values of:

a. Flange Outside diameter

b. Bolt hole diameter

Bolt Hole diameter would be located on the same tab (ex A05 Bolt Hole dia = 0.500 inch).

The Flange diameter would be located on the Flange tab. Upon selecting the flange tab and looking at the respective node point (ex. A05) it was clear why this dialog was displayed.

The Flange tab has not been updated with the required data. Note, outside diameter equals 0.00. 

Typically a user should proceed through each tab from Left to Right as indicated below

Load -> Flange -> Pipe -> Bolts -> Gasket

For each tab, again start on the left, fill in the first column with data, move the next column on the right updating data as required until all columns are completed. Once finished with the current row repeat for all flanges in the analysis. Once done with the entire tab, move to the next tab on the right and repeat.

After all the tabs have been updated then select the analyze button at the top and review Analysis tab / printed report. 

Solution:

When it comes to the flange analysis, update all columns and tabs from left to right. In this case this answer was to update Flange tab completely, to include Outside Diameter with a value and then proceed to update the next tabs (Pipe and Bolts) as mentioned above. Doing so would enable a value to be entered into the Bolt Circle field without the warning dialog being displayed. 

See Also

"Bolts*" Messages

Bentley AutoPIPE