How to use the "Hydrant Status" property in WaterGEMS and WaterCAD

  Applies To 
  Product(s): WaterGEMS, WaterCAD
  Version(s): V8i, CONNECT Edition
  Area:  Modeling
  Original Author: Scott Kampa, Bentley Technical Support Group

Problem

How is the "Hydrant Status" property used in WaterGEMS and WaterCAD?

Solution

Hydrant status (open or closed) defines if the hydrant's emitter coefficient is applied or not. If the status is "open", then any demand from the "Emitter Coefficient" field is applied. The emitter coefficient field is used to define the relationship between pressure and outflow when the hydrant is opened. If the status is set to "Closed", then no demand from the "Emitter Coefficient" field will be applied. 

Regardless of the hydrant status, any demand entered directly in the hydrant properties (in the "demand collection" or "unit demand collection" fields) will still be applied. Meaning, if you have an emitter coefficient set, and a base flow + pattern demand entered on the same hydrant and the status is "closed", then only the fixed demand will be used to determine the demand at that node. So, if you wish to model a fixed demand for hydrant flow but do not want to apply it for a certain scenario (to consider it as closed), then you will need to use a separate demand alternative in that scenario and set the fixed demand to zero. If you can represent the hydrant outflow as an emitter coefficient, then you would omit any fixed demands (remove anything in the demand collection and unit demand collection), enter the emitter coefficient field (see article below for guidance on determining that coefficient) and set the hydrant status field to Closed to model a scenario where the hydrant is not flowing.

See Also

Options for modeling an outflow that varies with pressure

Calculating available flow at a hydrant

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