Upright Sprinklers in Super Markets 4

[Adnan86]

Why all super markets or Food Stores are protected with Upright sprinklers. Is it just because there is no flase ceiling or it has something to do with the flow pattern of the upright sprinkler or the smoke flow reduction or just to avoid obstuction in storage areas. Please provide any code requirement if possible. Thanks

 

[cdafd]

Pick of the designer, does not matter which way the heads are installed, as long as it meets 13.

 

[Sdpaddler50]

As noted by CDA, its the choice of the designer. For typical light and ordinary hazard fuel loads, upright or pendent, there is not much difference in performance. I think a reason you see mostly upright heads is the constuction. Its generally easier for run the pipe below the structure (beams, trusses, etc), and then riser nipple up to the head. I am curious what the sprinkler designers have to say about this though.

However, when it comes to high pile storage, FM did a very extensive series of testing about 4 years ago and found the pendent head is superior for high challenge fires involving storage. This configuration allows the water to be directly discharged downward, where it's needed, as opposed to a pendent which requires the water to be directed upward, then back down to the fire by the deflector. That is why the flow and pressure demands of some upright heads are larger than the same K factor head used in the pendent position within the 8-9 tables. In very high celings, the upright heads are not even allowed for some configurations.

 

[fpst]

I've never designed an actual system before for installation, but I've been studying sprinkler design for a year and a half and I think the reason you see uprights in retail stores like Wal Mart is because:

1. In truss construction it's usually easier to riser nipple up, your crossmain might not always fit between the trusses (the A's and V's especially) so you won't be able to get all pendents within 12"-1" of the deck.

2. Uprights are usually a few cents cheaper per sprinkler, I think.

3. What if something got in the pipes? MIC, sediment (paper mills that use non city water), metal shavings, etc, on your small branch lines? Well it's going to collect right in that pendent type sprinkler orifice because of gravity.

 

[fpst]

Also, it just occurred to me that there could be an aesthetic angle to this as well. In my local Wal Mart the branchlines are pretty big, all painted white to match the ceiling. Would kind of look bad if you had pendent sprinklers (which can't be painted) dotting the ceiling.

 

[Dapke36]

From my experience, it's exactly as fpst stated. We usually spec uprights so the chances of a heavy object blocking sprinkler discharge flow are reduced, and also so that if the system is drained (for any reason) the sprinklers will drain completely, and not trap water.

 

[MGXFP]

From a layout point of view upright style sprinkler systems are much easier to install than pendent style sprinklers. It gives the installers more flexibility because you can always sprig up to upright fire sprinklers regardless of where the branch lines are. Where there is flexibility it is easier to make a profit because in commercial construction things change as the job progresses.

 

[Adnan86]

Thanks guys for the good explanation. Got something to learn.