FDC question

[cdafd]

Say I have two buildings on the same lot, say 20 feet apart.

Both have separate wet risers in them.

Owner decides to join the two buildings and make one.

So the fire sprinkler system is extended from one of the existing risers.

Per NFPA 13, is it legal,:::::::::

1. To connect the two together, in order to eliminate one fdc.

2. Put a check valve in the connection, so neither riser is over the sq ft limit.

3. The interconnection would be from each of the systems largest pipe.

4. The FDC would be on the system, with the check flowing into the other system.

 

[UFT12]

2. Put a check valve in the connection, so neither riser is over the sq ft limit

Would really like to see how this can be accomplished. Is one of the two risers going to be put out of commission or remain? What if you want to drain the system downstream the check valve?

NFPA 13 does not limit the area per riser rather the maximum area per floor. Although not stated in 13, the floor in this case is thought as one separate fire area (e.g. fire rated enclosure). If your case is various floors in such fashion, you could just connect the two risers with no additional valve but have all floors (or fire areas) separated with the common floor valve assembly per 13. Of course this should be something the local AHJ feel comfortable about it and that the costs involved for such modifications remain under reasonable limits.

 

[cdafd]

UfT

Both risers stay in service


Good point on draining