Moving pipes that are connected to junction structures invokes certain structure resize behaviors.
This section describes the structure resize behavior that is invoked in the following situations:
- moving the top of a junction structure (rim) up or down
- moving a pipe that is connected to a junction structure up or down
- moving the bottom of a junction structure (sump) up or down
These changes to elevation in the junction structure’s rim, connected pipes, or sump, could occur because the structure is grip edited, or because the referenced surface is edited, or because a connected pipe elevation is moved. Any of these types of edits may result in elevation changes to parts of the structure.
When a junction structure’s rim (top of structure) is moved up, the rim simply moves to the new elevation. Connected pipes, and sump elevations, remain unchanged.
If you try to move a junction structure’s rim down, to an elevation where it violates the vertical pipe clearance area, you will not be able do so. The rim must always be located above the vertical pipe clearance area.
The following table describes the resize behavior that occurs when connected pipes are moved up.
When a pipe that is connected to a junction structure is moved up, to the point where it violates the vertical pipe clearance, the top (rim) of the structure automatically moves up so that the pipe does not touch the vertical pipe clearance area. In this case, the structure’s rim elevation changes (moves up).
If you move the pipe up, but not to the point where it touches the vertical pipe clearance area, then the pipe is moved up, but the rest of the structure remains where it is. In this case, the structure’s rim elevation remains unchanged.
Understanding the Control Sump By Property
When you are moving a connected pipe down, there is a part property associated with the junction structure that affects the structure resize behavior in this situation. That property is the Control Sump By property, and it can be set to Depth or Elevation. When this property is set to Depth, the sump depth is controlled by the depth, based on the lowest pipe invert. When this property is set to Elevation, the sump depth is controlled by the elevation value of the sump. The resize behavior is different depending on how this property is set on the structure.
When a connected pipe is moved down, to a point where the pipe moves below the connected structure’s sump elevation, and the Control Sump By property is set to Depth, since the sump elevation is set to be controlled by the depth, then the sump elevation will be moved down, to a new elevation. This new sump elevation will be the depth of the lowest pipe invert, minus the sump depth value.
If a connected pipe is moved down, to a point where the pipe moves below the connected structure’s sump elevation, but the Control Sump By property is set to Elevation, then the sump will automatically move down, to an elevation equal to the lowest pipe elevation. This sets the sump depth to zero.
Using the sump depth grip, you can move a junction structure’s sump up to the point where it meets the lowest connected pipe. You will be prohibited, however, from moving the sump up past the point where it touches the lowest connected pipe.
When you move a junction structure’s sump down, the sump will simply move to the new elevation, and not affect any connected pipes, or the structure’s rim. This behavior is the same whether the sump is controlled by depth or by elevation.