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My fireflow report shows fire flow nodes failing due to low pressure at the suction side of a pump. What can I do about this?
If you are not concerned about this, you can create a special "low pressure" zone and select that as the zone for the node in question. This way it will not be considered in the automated fire flow analysis (unless you select to have a minimum system pressure constraint.) However, you may want to make sure the reservoir elevation upstream of the pump is correct and that the pump intake pressure meets the minimum NPSH requirements.
1) Create a selection set for all the junctions in the low pressure zone. There are a few different ways to do this that are described in the wiki linked to below.
2) With that selection set active in the drawing pane go to "Edit" > Invert Selection to select all the other elements. Right click in the drawing pane and choose "Create Selection Set".
3) Open the Fire Flow Alternative manager and chose the selection set created from step 2. This excludes all the low pressure junctions from the fire flow alternative.
4) Close the fire flow manager and compute the scenario
WaterGEMS Automated Fire Flow FAQ