FIRE PUMP SELECTION 1

[Adnan86]

I have seen a project where the fire pump of 10 bar discharge pressure with 300gpm was required. The existing city water pressure was 3 bar. The pump was selected for 10 bar discharge capacity without considering the available site pressure. As per my knowledge the required pump will be of 7bar capacity (10-3). Please let me know if m going wrong. Also suggest me any online pump selection links.

 

[stanier]

You can google "pumps" and answer your own question. Sulzer, Goulds, KSB, Sihi, Flowserve all make fire pumps. Suggest you get NFPA 20 and learn what is required in a fire pump.

Insurer take a dim view of engineers designing fire protection systems that have not done it before under the supervision of an experienced engineer. The risks are too great.

“The beautiful thing about learning is that no one can take it away from you.”
---B.B. King

http://waterhammer.hopout.com.au/

 

[Artisi]

Was the city main capable of maintaining 3 bar under all conditions? This might answer your question, failing that why not ask the engineer why made the pump selection.

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.)

 

[bimr]

This link has a discussion of the sizing issues.

http://www.firesprinkler.org/techservices/articles/020410sz_frpmp.html

8.2 SYSTEM DESIGN

8.2.1 Pressure

All water mains, including those not designed to provide fire protection, shall be sized after a hydraulic analysis based on flow demands and pressure requirements. The system shall be designed to maintain a minimum pressure of 20 psi (140 kPa) at ground level at all points in the distribution system under all conditions of flow. The normal working pressure in the distribution system should be approximately 60 to 80 psi (410 - 550 kPa) and not less than 35 psi (240 kPa).

http://10statesstandards.com/waterstandards.html#7.3.1

Do you know the size of the city water main that is servicing your facility? Has the City done a hydrant test?

 

[Artisi]

Of course everyone is assuming this is a NFPA / UL installation, but bear in mind there are other standards for fire pump installations with their own guide-lines requirements.

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.)

 

[Adnan86]

Artisti, Yes the Site water main is 3 bar under all conditions. Please let me knw if the following link is helpful to do my need full....

https://rcwapp.xyleminc.com/fp_select.asp

In this selection i am giving the DEVELOPED PSI = 10 bar( Demand)
SUCTION PRESSURE = 3 BAR ( Available site pressure)
I hope M goin right. But your support is much appreciated.

 

[Adnan86]

Bimr, Thanx for your answer.. The suggest link was really helpful.

 

[Adnan86]

Yes the City water Main is 200mm.