To Reverse Flow Direction
1. Click Modify. The Modify Pipeline dialog box opens.
You can also select a pipeline in the graphics window, right-click and choose Reverse from the shortcut menu.
2. Select Flow Direction.
3. Under Flow Direction, select an option from the Select Flow Unit list:
Series—Represents the smallest flow unit. A series starts from a pipeline end or junction and ends at a pipeline end or junction. It includes all pipes and fittings between these points.  The flow direction of all pipes and fittings in the series is the same. When the flow direction of a series is reversed, the flow direction for each pipe and fitting in the series is reversed.
Extension—Represents a set of connected series that form an open chain. All series in the extension have the same flow direction. When the flow direction of an extension is reversed, the flow direction for each series is reversed.
PipeLine—Represents a set of connected extensions. When the flow direction of a pipeline is reversed, the flow direction for each extension is reversed.
4. In the graphics window select one of the following to determine the flow unit:
Pipe segment
Fitting inserted at a free port
Pipeline
5. Click OK. The flow direction is indicated in the graphics window by arrows along the selected flow unit.
6. Under Flow Reversal, click Reverse.
7. Click Apply to change the flow direction for an additional flow unit, or OK to apply the changes and close the dialog box.
To display or reverse the flow direction in the graphics window follow these steps:
1. Click Pipeline View to display the Piping System Tree.
2. Select the pipeline in the Model Tree or graphics window.
3. Right-click and choose Show to display the flow direction, or Reverse.