Fire Hose cabinet

The typical 2 1/2" hose (63mm) fire hose should be abke to deliver 30 LPS approximately 500 USGPM. That's what NFPA also recommends.

Dear SV13, are you sure the flow will be 30 lps for 2 1/2", becasue the velocity in the hose will be around 10 m/s for such flow.is this velocity acceptable for such application, i think 30 lps is the flow required by the fire hydrant not the hose.

regards,

Sorry! I should have written 10 LPS. In Australia, we normally consider a number of hydrants operating depending on the size and class of building and multiply numbers with 10 LPS to calculate the total hydrant flow. A standpipe normally has 2 x 2 1/2" outlets. In USA, NFPA recommends use of 500 gpm for hydrants which is about three Australian hydrants.

Regarding hydrant v/s hose, a 2 1/2" connection is nrmally a standpipe type fire hydrant and not a hose connection.

I thought 2.5" hose standard flow was 250 US gpm. The number of outlets on pumpers is usually: pump capacity = (number of outlets) x 250.

The assumption may or may not correct. The velocity depends on the pressure and the lengthe of hose pipe. The volume then depends on the diameter of the hose. If you want it to be more accurate then you need to do a pressure drop calculation. The simplest is to use Bernaulli's equation that will give you an overestimate value. Add frictional losses if you want it to be more precise.

If you provide upstream pressure, downstream pressure (1 atm ) and length of hose then I may be able to give you some numbers.