Fire Ring Main for Standpipes

[Buildtech2]

One of our client is doing a high level of value engineering and expecing significant savings by changing the piping material from back steel to HDPE. Instead of connecting landing valve directly from the alarm check valve riser, the standpipe will connect to the external fire ring main made of HDPE piping and from that ring main, connections will be provided to the fire hose valves inside the building at the perimeter. By this arrangement, they dont have to run lengthy balck steel pipes inside the cargo terminal which will provide them significant savings. Please refer to attached sketch.

I have not seen such type of network anywhere bu technically, I think there is not problem. Appreciate if anybody can advise me the feasibilty for such network.

 

[LittleInch]

Nothing attached.

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[Buildtech2]

I apologies.

Please see attached file.

 

[cdafd]

I am thinking the diagram does not match the description.


Does this installation have to meet a certain standard??

If so what is that standard?

 

[Buildtech2]

I will provide more clear diagram. There is no such special installation requirement to meet. The basis of design is in accordance with NFPA and IBC.

The changes in standpipe design is mainly due to the value engineerign exercise. Just to reduce the balck steel piping as it is more expensive.

 

[stookeyfpe]

The basis of design is in accordance with NFPA and IBC.

Then your design needs to comply with NFPA 24 for the underground private fire service main and NFPA 13 for the automatic sprinkler system. If the building requires a standpipe, it need to comply with NFPA 14 and can be part of the automatic sprinkler system.

You can't use HDPE pipe for the underground. You can use plastic pipe but it is required to comply with the AWWA C900 criterion per NFPA 24. Your fire protection piping inside the building will need to comply with NFPA 13 and NFPA 14. You may have some areas where CPVC could be employed. I'm not sure how you're going to make the lead-in from the plastic underground piping into the building because that will need to be noncombustible.

 

[mk3223]

Checked out that the "red stripe" HDPE pipe can be used for the fire main underground. But, it's mainly for the underground portion. May consult with your local AHJ to review and approve your design proposal.

 

[Buildtech2]

Class-1 standpipes at two locations around the building from alarm check valve risers connect to a seperate HDPE underground fire ring main around the building perimeter. From this ring main, several connections will be provided around the building perimeter to connect to the several fire hose reels inside the building. This is basically to avoid long black steel pipes inside the cargo terminal. I would like to know if this is acceptable.

 

[Buildtech2]

Please find attached diagram which shows two fire main rings. One for sprinklers risers and another for class-1 stand pipes.

 

[LittleInch]

You can't use HDPE pipe for the underground.

Errr, the latest version of NFPA 24 in section 10.1, table 10.1.1.1 states PE pipe to AWWA C906 standard?? This seems to have been an addition to the 2007 version of the code.

~Fittings on the other hand only list metallic systems.

therefore I believe that underground PE pipes are allowed for, but all other equipment needs to be metallic (standpipes, sprinkler lines etc.
NFPA 14 on standpipes lists only steel, copper and DI pipe

Your Iso does not seem to include the change of pipe material

Buildtech2 - You do know that you can access NFPA codes for free online via the NFPA website don't you?

SO, IMHO, you can't use PE pipe within the building and comply with NFPA, nor would it seem a good idea. Plastic melts quite easily when exposed to fire / heat and would not be most peoples choice for a fire water supply system potentially exposed to such conditions.

You could run your main around the building underground with a lot of tap offs, but not sure how this works with your design or layout

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Also: If you get a response it's polite to respond to it.

 

[Buildtech2]

May be I could not expalin it well in the previous posts. It is to be noted that HDPE pipes will only be used underground wheareas black steel pipes will be used for all above ground piping. The client want to save money by minimizing the black steel pipes inside the cargo terminal as it is very expensive. Therefore, he wanted to use seperate underground HDPE ring main for class-1 stand pipes outside the building. The connections will be made in this ring main with HDPE piping at different location and enter into the building underground and rise up with black steel pipes to connect to the fire hose valves. By this arrangement, he dont have to run more black steel piping inside the cargo terminal.

 

[LittleInch]

It would help if you marked on the ISO which sections are U/G and where the break is between HDPE and steel.

So long as the bit which come above ground is metal then I believe that system will be acceptable under NFPA requirements, but the AHJ acceptance is your key issue.

I think what you're saying is that instead of having a metal pipe run round the inside of the building, you're going to run a buried PE pipe around the outside of the building and then come above ground to feed the relevant hydrants, hoses, sprinklers etc??

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[cdafd]

Is this in the US?

Where are you getting your water supply and pressure from?

For just the fire hose valves,,, from the exterior of the building to where you want the pipe to come up into the building, what is your average distance?

 

[Buildtech2]

LittleInch: Yes, You are absolutely right.

cdafd: This project is in Dubai. There will be firefighting pump sets and above ground storage tank for the fire water supply.

The pipe will come into the building underground and then rise up to connect with black steel pipe. The distance from fire ring main to the building perimeter where hose valves will be installed is approximately 30 m.

 

[cdafd]

“””The distance from fire ring main to the building perimeter where hose valves will be installed is approximately 30 m.””

But how far average does the underground run from the perimeter of the building,,

Till it comes up through the slab, to the pipe for the hose valve?

 

[TravisMack]

I see PE, not HDPE for UG pipe in NFPA 24. A keyword search for HDPE does not produce any results in NFPA 24.

If you use materials that are acceptable per NFPA 13, 14, 20 & 24 then you will be OK.

If I understand your sketch correctly, the underground main for the standpipes is essentially your bulk mains. You will need to have an isolation valve for the lead-ins to the standpipes. You could do a combination line and omit one of your fire rings.

You should hire a consultant more familiar with this than yourself and see what they think about your situation.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

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[LittleInch]

HDPE is a generic description, but is covered by PE 4710 grade PE which is covered in AWWA C906 which is referenced in NFPA 24 etc for buried pipe. Therefore HDPE is covered.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[TravisMack]

Thanks for the clarification. It's always great to learn. We don't get much into underground fire line design and details. 99.9% of our stuff is overhead design work.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

"Follow" us at

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