Combination Riser
Combination Riser
(OP)
If two combination standpipes were interconnected, but there was one floor control valve, that would still mean the floor was supplied by two or more combination risers. Correct?
I'm a little confused at a code that states a high rise shall be served from two or more combination standpipes/sprinkler risers.
I am 99.9% sure that means one control valve is acceptable providing that before that valve is double fed. If one standpipe goes down, that control valve still gets it's water.
I'm a little confused at a code that states a high rise shall be served from two or more combination standpipes/sprinkler risers.
I am 99.9% sure that means one control valve is acceptable providing that before that valve is double fed. If one standpipe goes down, that control valve still gets it's water.





RE: Combination Riser
RE: Combination Riser
It would seem that if you are double feeding each floor sprinkler system with only one floor control assembly, you would not be able to take one standpipe out of service without taking both out of service. NFPA 6.3.2 requires that valves be arranged so a standpipe can be isolated without interupting other standpipes.
RE: Combination Riser
Here is my real life example: Fire on the 10th floor of a 30 story high rise. FD responds, the sprinklers suppress the fire, and the firefighters close the valve. One hour later, another fire occurs on the 22nd floow. FD responds, along with a bunch of police officers, and finds a working fire controlled by the sprinklers on the 22nd floor. The fire goes out and the cops arrest an arsonist on the 1st floor when the FF recall service traps the stupid bastard. I witnessed this once 25 years ago. My point: the codes work.
It's not that hard of a problem. I think we are getting lost in the terminology.
I hope I didn't offend anyone.
Thanks.
RE: Combination Riser
BTW, I really enjoyed the seminar on storage. Thanks for the clarification on the EC-25.
I agree that we are probably getting confused with the terminogy.
While NFPA wants the standpipes interconnected so that FDC flow from a single FDC will flow to all standpipes, my understanding is it also wants to be able to isolate each standpipe for service. Downstream of the connection of the FDC to the common standpipe pipe, there needs to be a control valve to isolate.
I've attached a rough schmathic of what I originally understood Firefreak to be describing with a single sprinkler system floor control valve(assembly) feed from a dual supply.
If this is in fact the arrangement Firefreak was describing it would seem the standpipes cannot be isolated unless you were also going to add in shut off valves on the feeds from each of the standpipes to the sprinkler zone control assembly.
Certainly no offence taken here and hope none on your end either. Just trying to take the opportunity for me to learn something.
RE: Combination Riser
I'm glad you learned from my seminar.
Your design meets the letter of NFPA 14. The standards require valves so that systems can be maintained or modified to protect the building occupants in the event of changes to a building. Under the IFC, these valve require electric supervision, which I believe has done a great deal for improving the reliability of fire protection systems.
Your design is compliant, and if I could issue you a permit, I would.
RE: Combination Riser
Is it at all possible to get some enlightening on the storage seminar referred in above post?
Best Regards
Qalander(Chem)
RE: Combination Riser
Here is a warehouse fire protection seminar if you are looking for this type of training
htt
Details can be found here
http
This is NOT the seminar Stookey was/is involved with.
Just an FYI
Tom
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Fire Sprinklers Save Firefighters' Lives Too!
RE: Combination Riser
From the sounds of it though, you are all in agreement and as long as that one control valve is supplied by two seperate risers, everything is all set. It makes perfect sense because each riser has it's own isolation valve so one goes down, the other stays open.
Thanks everyone!
RE: Combination Riser
With this arrangement if you have to change a Fire hose valve or work on any part of say the riser on the left you cannot isolate it. Lets say there's a 'isolation valve' at the bottom of each riser. You close the Isolation valve at the bottom of the riser on the left. The riser of the left is still going to be full of water and pressurised because the water can travel through the Riser on the right and then through the pipe that is connecting the standpipes feeding each floor sprinkler assembly and up and down the riser on the left from there. You may as well not have an 'isolation valve at the bottom of the riser.
To work with the arrangement shown I still think you would need additoinal shut off valves on the feed pipe from each standpipe (another 2 per floor).
If the sprinkler systems are in fact required to be dual feed (and I really like the idea:)), I think 2 floor control assmeblies would be preferable (one at the stairwell at 2 ends of a corridor or something). A single main connecting them with branchline coming off it. You would be coordinating and installing less pipe as you would not have to connect feeds prior to running pipe to fed sprinklers (better for calcs too). You would also need a check valve (per NFPA 14) for each floor control assembly. Then you would have the ability to shut down one riser by closing an isolation valve at the bottom of each riser and keep and other standpipe and sprinkler systems live.
RE: Combination Riser
I agree with you. You can't isolate the standpipe in the arrangement you have shown. You would need to put a check valve at each connection coming from the riser in order to isolate a given standpipe.
Travis Mack
MFP Design, LLC
RE: Combination Riser
Cidona
do you have a copy of nfpa 14?? look in appendix A and check out some of the riser details around 7.1, not sure if this answers some of the questions.
RE: Combination Riser
cdafd. My understanding would be NFPA 14 doesn't show/require the indivigual sprinkler systems being 'dual fed'.
RE: Combination Riser
I think A.7.b maybe show a dual feed nfpa 14 2007
6.3.8.3 Where sprinkler system piping supplied by a combined system is supplied by more than one standpipe ("loop" or "dual feed" design), a sign shall be located at each dual or multiple feed connection to the combination system standpipe to indicate that in order to isolate the sprinkler system served by the control valve, an additional control valve or valves at other standpipes shall be shut off.
RE: Combination Riser
6.3.8.3 to me would not require sprinkler systems to be dual fed but says when they are being done, signage for isolation valves are required. This would further insinuate that additional valves for isolation would be required.