A Warning message in AFT Impulse. (PFA Module Only)

Full message is:

Pipe X - Station Y pressure is below 10% vapor pressure margin. Pressure = Z. Note: There are also N other locations.

In the PFA module, resonant frequencies are calculated for the modeled system. If these frequencies are caused by a positive displacement pump, the PFA module will automatically generate scenarios that evaluate problematic pump speeds. As part of the calculations when modeling these pump speeds, the PFA module will calculate the lowest pressure margin above vapor pressure. If the relationship between the lowest pressure and vapor pressure shown in Equation 1 below (from American Petroleum Institute,  2010 Equation A.3) is not satisfied, this warning is displayed.

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