Fire hydrant standard
Fire hydrant standard
(OP)
get a question:
Can fire hydrant be installed on 4-in water line? all the fire marshall regulated that it shall be installed on at least 6-in water line.
Some of my friends told me that it used to be OK to install FH on 4-in water line.
can anyone give me a more detailed introduction? Thanks.
Can fire hydrant be installed on 4-in water line? all the fire marshall regulated that it shall be installed on at least 6-in water line.
Some of my friends told me that it used to be OK to install FH on 4-in water line.
can anyone give me a more detailed introduction? Thanks.





RE: Fire hydrant standard
RE: Fire hydrant standard
Modern water systems are installed with a minimum size of 8" piping. Fire flow is typically a minimum of 1500 gpm and i susually a larger flow depending on the application (residential/commercial).
RE: Fire hydrant standard
RE: Fire hydrant standard
Most insurance companies and rating agencies typically require a fire flow of a minimum of 1500 gpm or higher depending on the building zoning mix (residential and or commercial).
That is why modern water systems are installed with a minimum size of 8" piping. It is difficult to get the required fire flow in a 6" water main.
To answer your question, 4 inch pipe is too small for a fire hydrant.
Since the difference in cost between 6" and 8" in minimal, it is recommended to use 8" minimum size of pipe.
RE: Fire hydrant standard
If you actually perform a fire flow analysis for your system, and are trying to use a 6" main, you will usually exceed the maximum allowable velocity, and/or will have so much head loss that you will not be able maintain the minimum residual pressures during a fire flow analysis. It only gets worse if you run the same analysis when using a 4" main.
RE: Fire hydrant standard
Thomas J. Walz
Carbide Processors, Inc.
www.carbideprocessors.com
Good engineering starts with a Grainger Catalog.
RE: Fire hydrant standard
RE: Fire hydrant standard
"Public mains shall be of ample size, in no case smaller than 6 in. (152 mm)."
Has this been somehow changed to allow smaller pipes?
RE: Fire hydrant standard
However in the Petroleum Refining set-up I served
Witnessed the basic hydrant's design; almost invariably the
6" dia pipe was used having one 4" dia take-off and two 2.5" dia take-offs
Near the capped end.(Pillar Type were mostly employed)
Hope this helps
Best Regards
Qalander(Chem)
RE: Fire hydrant standard
RE: Fire hydrant standard
even from 20" dia varying to 10"dia designed to cater Flowrate needs;
however the hydrants were almost always fabricated with 6" dia pipe.
If I recall correctly.
Best Regards
Qalander(Chem)