![]() After the test is performed, they provide a fire hydrant flow test sheet with a standard layout and full details.Ĭalculate with orifice equation 4.7.3 of NFPA 291. While the flow hydrant is flowing, the rate of flow is measured (gpm) and information about the outlet is recorded for further calculations.Įxcerpt of flow test results from MWS in Nashville.The pressure at each hydrant is measured again – referred to as “flow pressure” at the flow hydrant and “residual pressure” at the monitoring hydrant.The valve on the flow hydrant is opened fully.The static pressure is measured at each hydrant.A pitot gauge is connected to the flow hydrant.A capped pressure gauge is connected to the monitoring hydrant.A Pitot flow test is pretty standard for hydrant testing.o No matter your locality, a fire flow test is performed using a flow hydrantand a monitoring hydrant. Make sure you know whether you can do the test yourself or not. In the City of Nashville, they don’t do flow tests and you have to either hire someone or do it yourself. For example, in the City of Lebanon, the utility provider doesn’t perform flow tests, so an employee or subcontractor has to go out and do it after scheduling with the City. Different municipalities have different procedures. Obtain hydrant flow information from your local municipality. If that doesn’t do it, you may need to ask the utility provider to run it on their full network model (they probably have one). ![]() In that case, try setting up a model using only one source, as the second will generally just add more capacity. Since this is a fake pump, these points will be based on the results of a hydrant flow test.īE WARNED this approximation doesn’t really work if you are connecting to the existing municipal water system at multiple locations (aka cross-connecting). For real pumps the full curve can be measured, and is generally available from the pump manufacturer. The “reservoir” represents the static pressure available, and the “pump” is used to approximate the relationship between pressure and flow when various demands are exerted on the system.Ī pump curve is defined using at least three reference points where both pressure and flow are known. This model uses ductile iron pipe (DIP).Ī pump-reservoir approximation is a method of representing the available flow from a municipal main without all the real-world data from the entire water service network (aka, way too much data). The “roughness coefficient” is a Hazen-Williams coefficient – don’t try to put a Manning’s here or you will have a bad day.Pipe diameter is something you’re designing, but should definitely not be bigger than the main you’re connecting to.Pipe length comes directly from your diagram.“Start Node” and “End Node” will be generated from the diagram you just drew.Now we can start entering in the pipe information from the exhibit. The blue scribbles are me drawing on the picture and not actually in the EPAnet diagram.
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