Douglas, The Health Department is the who that regulates the why, where, when and what regarding water quality. They'll want a Double Check Backflow Assembly (DCBA) or Double Detector Check (DDC) on the incoming riser before you change to black or galvanized steel, and an Reduced Pressure Backflow Assembly (RPBA, often mislabeled RPZ because it has an area between the checks known as the reduced pressure zone) on each of the loops. Oregon, like Washington, probably has a retroactivity clause in the health code so whether a new system or old you'll need these if someone knowledgable is the regulator.
Now to the systems. Depending on when this was built determines if you can use that piping configuration with the check valves with holes you're alluding to. But here's the rub, if the health department makes you change to a RPBA you'll need to drain the system, if you have that configuration the building has to be over five years old and needs a five-year internal inspection so you'll have to drain the system, or if you've been working on the system you have likely drained the loops. As per Charles' comments you can't put the old stuff back and you can't buy the listed pre-mix that doesn't exist. Back to the holes in the check valves question: Yes, in all the check valves in the loop in that old piping configuration. The hole and the differences in elevation of the water only pipe vis-s-vis the piping with solution is to allow for the entire system to absorb the expansion of the anti-freeze solution (more dramatic than water at normal temperatures) without allowing ant-freeze solution to creep back into main system. If you have an RPBA then you need to use a properly sized (calculated) and listed expansion tank to regulate the pressure. On Sat, Jan 28, 2017 at 5:10 AM, Charles Thurston <[email protected]> wrote: > Hello Douglas, > > I got this from the 2013 code in the front where it talks about the > changes from the prior version: "The use of antifreeze in new NFPA 13 > sprinkler systems is now prohibited unless the solution use has been listed > and the listing indicates illustrates the inability for the solution to > ignite." > > From the information provided you are going to need an RPZ > backflow between the antifreeze loop and the system. You have to have one > to isolate it from a drinking water supply. RPZs are not allowed to be > installed in a pit. Biggest problem of installing an RPZ as per Figure > 7.6.3.3 is each time you have a surge in the system it is going to let > excess pressure out of the antifreeze side and dilute the antifreeze > solution. > > Figure 7.6.3.1 gives a layout if you change the backflow outside to > be above ground and put the PRZ out there. > > Saturday, January 28, 2017, 1:43:41 AM, you wrote: > > > We have a building with 2 outside canopies, each is protected by an > antifreeze loop. The sprinkler system has a backflow in a pit. Do each of > the 2 antifreeze loops need a one way swing check valve, with a hole in > the clapper? I will put a test port at each end of both loops, even though > the loops are not 150 gallons. > > > > > *-- Best regards, Charles Thurston * > [email protected] > > > > > > *MYRTLE BEACH FIRE SAFETY GROUP A Division of Pye-Barker Fire Safety 1445 > Cannon Road Myrtle Beach, SC 29577 (843) 916 - 8787 <(843)%20916-8787> > (843) 839 - 3473 <(843)%20839-3473> facsimile* > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler. > org > > -- Ron Greenman [email protected] 253.576.9700 The Universe is monstrously indifferent to the presence of man. -Werner Herzog, screenwriter, film director, author, actor and opera director (1942-)
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