| Applies To | |
| Product(s): | AutoPIPE |
| Version(s): | ALL; |
| Area: | Modeling |
| Date Logged & Current Version |
March 2024 24.00.02.243 |
Problem:
How to model underground valves using AutoPIPE?
Example,
Solution:
When modeling a valve and applying soil properties, the soil stiffness is only considered for the horizontal part of the valve, not for the vertical actuators or handles.
The only aspect we are not considering is the resistance from soil stiffness in the vertical direction by the handwheel or actuator of the valve to the center line of the valve. This is because soil stiffness is not accounted for in the handwheel or actuator of the valve.
To address this issue, we can model the valve as a tee with three legs: two for the header and one for the branch. In the branch, we need to consider the length of the actuator and then apply the soil properties to that segment, as shown in the screenshot below.
Follow the steps given below to model the Valve as a tee:
1. Delete the valve.
2. Insert a mid-point A260 between A81 to A82.
3. Convert the point A260 to a Tee point through Modify > Convert point to > Tee.
4. Now model a vertical branch from A260 to B01 with some length and again insert a run from B01 to B02.So, the total length from A260 to B02 should be equal to L as shown in screenshot above.
5. Similarly insert a point in header runs also from A81 to A261 and A260 to A262.Specify the length as per your choice.
6. Now specify the soil properties to A81 to A261 and A262 to A82 and B01 to B02.
We are leaving certain runs near Tee point because of latest update in V24.00.02.243 the Analysis will not start due to B31 J limitation that soil cannot be applied to tee points and hence give you the following error message below:
E2261-106: B31 App J: Flexibility and SIF calculations are limited to non-soil tee points and cannot apply to the following tee point(s): A260
7. Input the weight of the valve at Node A260 from Insert> Xtra data>Additional weight. As show in image below:
Note: You can also make these tees rigid, similar to a valve, if you only want to consider thermal effects and not pressure.