CPVC residential fire sprinkler system

[EastHumboldt]

My brother has one of these systems in his new house, with the special orange CPVC pipe. He poked a hole in it and we had to drain the system to replace a couple feet of pipe. We’re aware that this isn’t standard white pvc pipe and we can’t use that for the repair. We have ordered some of the special orange pipe, orange fittings, and the special glue. The actual repair is a pretty straightforward plastic plumbing job involving a couple ells and couplings.

Back in the day, when I was a commercial building maintenance mechanic for the city, we had a lot of black iron fire sprinkler systems that required treated water to keep the pipes from corrroding too bad or antifreeze where the pipes were in an exterior soffit. Since the system he has is entirely indoors and all plastic except the brass service valves, I’m assuming we can just turn on the valves and refill it with standard city water?

The system is fed by a 1-1/4” line that tees. One side of the tee is the sprinkler system and the other side is his domestic water supply. And do we need to worry about bleeding any air? I’m also assuming if there a ever was a fire, the system is “ self bleeding” when a head pops?

 

[Habitat#1]

Is there a backflow preventer that keeps the water that sits in the sprinkler side from going back into drinking water side?I'm not a plumber but that seems like the type of place that needs one. Was he required by local codes to install or chose to?

 

[EastHumboldt]

Yes there is a BFP valve. Ball valve shutoffs above and below the BFP and a service drain valve (looks like a globe valve) teed in above the upper ball valve. That’s where we drained the system.

This is the riser in the garage. The pipe that he drilled is in the house.

 

[EastHumboldt]

No sprinkler guys on here?

 

[carlc]

Im not normally a "consult a professional" guy, but this is probably one of those instances. He paid good money to have the system installed, probably saves on insurance premiums, and the system gives him piece of mind. If its repaired DIY, will you ever be certain its repaired correctly, and going to function when needed? If there is a failure, what will insurance say? Sorry for the negative answer, but fire suppression isn't something to mess with without proper knowledge.

 

[JJ1179]

I can say that in the city where I work, the FS system also feeds the toilets, so there’s constant flow in the system which prevents the system from being over pressurized due to the back flow valve. When there is a pressure surge from the city water, the system pressure can gradually rise and without being flushed and “drained” from flushing the toilet bowls, it would eventually be over the maximum functional working pressure designed for that specific FS system for the house. I would drain the system as you did, make the needed repair and then turn it back on. Just be sure and follow the manufacturer’s suggestions for glue curing times before re pressurizing the system. The gauge will read the static pressure once finished and turned back on. Where I’m at, the max pressure for FS systems is 80psi. Most house pressure is in the neighborhood of 50-60psi and well within working range. The FS will have a minimum and maximum working pressure designed for that system.