Improper use of partially full pipe feature

A Transient Solver Error in AFT Impulse

Full Message Text

Error occurred while running Solver. Improper use of partially full pipe feature.

Explanation

This error occurs when the user presses Cancel on the "Problems With Partially Full Pipe Feature" pop-up that may be displayed after the Waterhammer Assistant as a pre-run check on the Solution Progress window. This action cancels the transient run.

One of the pipes in the model is using the Partially Full Pipe feature and is incorrectly defined according to the requirements. For example, the "Problems With Partially Full Pipe Feature" pop-up may list a pipe number and the following messages:

• Pipe X - Pipe is horizontal.

• Pipe X - Outlet is below inlet and inlet is connected to a <Junction Type> junction (Y).

• Pipe X - Cannot start a pipe as partially full with a Air Valve junction (Y).

  This is because it implies that the Air Valve is open, which is not allowed in steady-state.

• Pipe X - Cannot use a <Junction Type> as the high elevation junction.

• Pipe X - Pipe has two sections, which may not be enough to allow tracking of partially full pipe level during the transient simulation. You can resection the system using the Section Pipes window with more sections in the controlling pipe.

Required Action

To resolve the issue, the affected pipe should be compared against the requirements listed for the Partially Full Pipe feature. The model will need to be modified such that it conforms to the limitations of the Partially Full Pipe feature, or alternatively, you can disable the Partially Full Pipe feature in the affected pipe.