Hydraulically Calculated Pipe Diameters for Fire Fighting Networks
Hydraulically Calculated Pipe Diameters for Fire Fighting Networks
(OP)
I am searching for the software to calculate hydraulically the pipe diameters of the firefighting network for extra hazard classification of the sprinkler system as per NFPA.
The sizing is to be calculated hydraulically and not by the Pipe Schedule System of NFPA.
In Chapter 13 of NFPA there is an example of the Hydraulic Calculations, but I believe that is only to size the Pump Capacity for the remotest area of sprinkler activation and that procedure does not give the pipe sizes for the rest of the network.
Some of the Software Companies that I have consulted contend that they have the software for the entire network but the pipe sizes must be entered from the Pipe Schedule System. This is puzzling given that the very purpose of going to the software is to calculate the diameters hydraulically without any reference to the pipe schedule system.
Please shed some light on this subject and recommend some software that could do the needful. Thanks.
The sizing is to be calculated hydraulically and not by the Pipe Schedule System of NFPA.
In Chapter 13 of NFPA there is an example of the Hydraulic Calculations, but I believe that is only to size the Pump Capacity for the remotest area of sprinkler activation and that procedure does not give the pipe sizes for the rest of the network.
Some of the Software Companies that I have consulted contend that they have the software for the entire network but the pipe sizes must be entered from the Pipe Schedule System. This is puzzling given that the very purpose of going to the software is to calculate the diameters hydraulically without any reference to the pipe schedule system.
Please shed some light on this subject and recommend some software that could do the needful. Thanks.





RE: Hydraulically Calculated Pipe Diameters for Fire Fighting Networks
To make pipe design practical you must make some initial assumptions, as follows
Spacial position of each sprinkler
Location of the source(s) of water
Location of pump(s)
Topological configuration of the piping system (network)
Determine the length of each pipe
Material of each pipe (roughness)
Inlet pressure at your sources and/or outlet pressures at all sprinklers
Assume a Diameter of each pipe.
Required flows out of each sprinkler.
With the above information, you will determine the pressure losses and find out the flows possible at each sprinkler. You will change the pipe diameters and inlet and/or outlet pressures and the pump, and/or change the piping configuration as necessary to ensure that you have the correct flows issued by each sprinkler.
Maybe what you really want is to hire an engineer that understands all of that. Otherwise get some training in it yourself, which is better done before you start trying to buy magic silver bullets.
RE: Hydraulically Calculated Pipe Diameters for Fire Fighting Networks
The pipe schedule system of pipe sizing is fairly straightforward, and there is no need to use any software for that.If the hydraulically calculated pipe network requires input of the pipe diameters that are taken from the pipe schedule system table developed by NFPA, then one could simply size the system without the software.
I appreciate your response but I am still waiting to hear someone say:
YES WE NEED TO ASSUME THE SAME PIPE DIAMETERS AS IN THE PIPE SCHEDULE TABLES OF NFPA,
OR
WE CAN PLUG IN PIPE DIAMETERS AS ZERO, BUT THE PROGRAM WILL OUTPUT THE REQUIRED DIAMETERS…..
RE: Hydraulically Calculated Pipe Diameters for Fire Fighting Networks
Just use the canned scheduled pipe diameters in the programs and be happy you don't have to deal with impractical computer generated results. That would require more work then a skilled designer could do in pass #1.
RE: Hydraulically Calculated Pipe Diameters for Fire Fighting Networks
RE: Hydraulically Calculated Pipe Diameters for Fire Fighting Networks
RE: Hydraulically Calculated Pipe Diameters for Fire Fighting Networks
RE: Hydraulically Calculated Pipe Diameters for Fire Fighting Networks
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Hydraulically Calculated Pipe Diameters for Fire Fighting Networks
Segments near the pump discharge normally have higher flows, thereby requiring largest diameters, as full source flow has usually just been pressured up and flow has yet to be split amongst any laterals running to the sprinklers.
RE: Hydraulically Calculated Pipe Diameters for Fire Fighting Networks
Thanks again to BigInch, Artisi.......and all.