14. Why is the gravity load case results weigh more than the Hydrotest gravity load case results on


Applies To
Product(s):AutoPIPE
Version(s):ALL;
Area: Results
Date Logged
& Current Version
Oct 2022
12.08.01.010

Problem:

Why is the gravity load case results weigh more than the Hydrotest gravity load case results on a Gas pipe line modeled in AutoPIPE? 

Example: Output report

Solution:

First step when diagnosing an issue, start with reviewing AutoPIPE's help for hydrotest

Warning: be sure to read all of the notes mentioned.

From AutoPIPE Help:

As mentioned, review the options on the hydrotest dialog:

Confirm "Include Insulation and cladding" setting as needed. In this case, when the setting is enabled, the gravity results are now understandable:

Scenario #2:

The GR load case for hydrotest analysis set was nearly double that for Gr load from Analysis set #1, why

Answer: 

Similar to above, take the time to read about the hydrotest load case and it settings to know exactly the weight taken into consideration for Hydrotest Gravity load case. 

Next, take the time to thoroughly review the complete model input listing report. There could be any number of small settings that would affect the GR load case

Example:

- Pipe ID Specific Gravity was set incorrectly.

- Impost support displacement attached to GR load case

- Add weight setting was wrong (ex. +ve instead of -ve).

- etc...

See Also

Hydrotest FAQ

Bentley AutoPIPE