City main pressure

[Taha9111]

Please advice me about the city main fire water header pressure ? what should it be ?

what is the refrence to NFPA please?

 

[firepe]

Are you kidding? Looks like a fishing expedition.

You need to provide a lot more information. What is the fire water for? What are you protecting? for starters, and we'll go from there.

May I suggest you go hire someone qualified, to answer your questions.

 

[Taha9111]

Thanks for the reply. I am not kidding .I was involved in a fire caused me to loose $4 Millions and come to find the fire hydrant pressure was 26 PSI, bearing in mind that our industrial plants are provided with 150-200 psi net pressure , but this building to be in a fire water remote area where fire water was only 26 psi


My question is who or what regulates the city fire water main header pressure for cities and industrial cities?

 

[stookeyfpe]

If it is a municipal water supply, the water purveyour will most likely be indemnified. Your business constructed a plant in a location without adequate fire flow. It sounds like a building was erected far from the water supply source and due to pressure drop, sufficent fire flow was not available for the necessary demand.

Water utilities are generally regulated by Utility or Corporation Commissions, Water Commissions, or both. Generally these agencies stay away from fire flow issues and are primarly concerned that the water remains potable and waste water is properly disposed of and treated.

Is your fire the one currently burning at a steel mill in Midlothian, Texas?

 

[Taha9111]

No sir. I am in saudi arabia, still didnt get the answer tomy question.
Would you refer me to a code or a resource defind what pressure the city main should be on please.

 

[stookeyfpe]

I can't give you any guidance on Saudi Arabia codes and standards.

I'm in the US. You need to contact someone in your local government for the answer to your question.

Good luck.

 

[Taha9111]

we are using the NFPA code sir

 

[stookeyfpe]

Seek professional design assistance. Attached is link for a firm who appears qualified to perform the analysis and engineering review you are seeking:

http://www.teejan.com/gp_saudi_safety.html

This is not a referral as to their qualifications - it is based on simple web search.

 

[rconner]

While claiming no necessary relevance in Saudi Arabia, there is however an AWWA manual of water supply practices M31, entitled "Distribution System Requirements for Fire Protection". This manual explains of course that far more than just "pressure" per se should be considered when designing combined water systems that are to provide fire protection needs. While I don't know that I have the latest copy, at one time this manual was prefaced, "The adequacy of a water protection system for fire protection depends on the fire flows required."
There are various methods/authorities mentioned in this manual for calculating fire flow requirements, but generally I think some of the higher classifications or demands per most methods/authorities are for protection of occupancies such as industrial plants etc.

 

[DonPhillips]

I agree with Stookeyfpe, it depends on who supplies your water. There may not be a code governing it and even if there is, there may be immunity. I would start questioning your water supplier.

Don Phillips

http://worthingtonengineering.com

 

[MJCronin]

Taha...

If your plant was designed in accordance with NFPA standards in the USA, there should have been a detailed evaluation by a registered fire professional of the fire water source (as mentioned above.)

This detailed evaluation would include both the source pressure and flowrate.

If the flowrate was found to be acceptable, but the supply pressure was low, a booster pump arrangement would be necessary and should be included in the final plant design.

The custom booster pump must be configured, designed and periodically tested in accordance with NFPA guidelines. The required boost pressure and flowrate would depend on the plant configuration.

Some companies offer pre-packaged skids designed just for this purpose.

http://www.pattersonpumps.com/fireprepac.html

Looks like you awarded your plant design to the low bidder and got what you paid for..........

-MJC

 

[Bhhowie]

Taha;

The answer in most cases in the US is nobody has the answer. There are places where a 26 PSI residual pressure is sufficient for use, if the flow is sufficient to boost.
A static pressure of 26 PSI is a very poor situation.
If you had very large water mains 26 PSI residual pressure may not be a bad thing.
Hope this helps.