This is permissible. Conceptually, it was something that was introduced when antifreeze became a problem around 2010. The Tyco RCP-1 is no longer available. Low pressure dry vavles are an avenue towards making these systems work with CPVC piping material.
While others in this thread have indicated low supervisory air (15 psi max.), and the requirement for water delivery in 15 seconds, what has not been said is tha residential sprinklers must be listed for dry system use, most are not. Sprinklers with a dry system listing delayed water for 15 seconds which meant the fire was larger and the required flows and pressures are going to be higher than most residential sprinkler listed flows and pressures. Thank you, Brandon Telford Product Technology Manager The Reliable Automatic Sprinkler Co. Inc. On Tue, Mar 3, 2026 at 11:38 AM Matt Grise <[email protected]> wrote: > It can be done! > > There are a couple of different ways to do it. > > 1- once upon a time, Tyco-Simplex-Johnson Controls offered a low-pressure > residential dry system kit/box. Not sure if that is still available. > 2 - there are at least a couple low pressure dry pipe valves that will > work with CPVC dry systems. The trick is that you have to use a very low > pressure supervisory air. Some of the CPVC pipe documents out there don't > specifically list that they are ok for dry systems, but if you pester the > manufacturers, they have the documents available. > > Be sure to be careful about where you use the dry systems. NFPA 13 > requires water delivery of 15 seconds to heads protecting dwelling units. > > I have seen CPVC dry systems used to protect balconies in apartment > buildings. > > Matt > > On Tue, Mar 3, 2026 at 10:28 AM Patrick Tomaszewski < > [email protected]> wrote: > >> Never heard of this. >> >> Ive only ever seen standards and manufacturers documentation saying that >> CPVC products are approved for wet systems only. >> >> >> >> Maybe instead of telling him no, you can ask client to produce the >> documentation saying it is acceptable – we can do whatever the client wants >> as long as it complies with codes, standards, manufacturer’s docs, and AHJ >> approval. >> >> >> >> That way you don’t have to risk being wrong, while maintaining compliance >> based on your own knowledge. >> >> >> >> [image: signature_2544299208] >> >> Patrick tomaszewski | *Estimator* >> >> www.valiantfireco.com <http://www.valiantfireco.comorg> >> >> [email protected] <[email protected]> >> >> 📍3910 Howe rd. Wayne, MI 48184 >> >> *“Every Second Matters.” * >> >> IG <https://www.instagram.com/valiantsec.mi/> • FB >> <https://www.facebook.com/valiantsec.mi> • LINKED IN >> <https://www.linkedin.com/company/valiant-security-llc> >> >> >> >> >> >> *From:* Fpdcdesign <[email protected]> >> *Sent:* Tuesday, March 3, 2026 11:21 AM >> *To:* Sprinklerforum <[email protected]> >> *Subject:* [Sprinklerforum] CPVC in dry system >> >> >> >> I had a client tell me this morning that there was something about CPVC >> being approved for residential dry systems where low pressure dry valves >> were used. I have never heard of it and can’t find any references about it. >> Before I tell him no, is there something that I am missing? >> >> >> >> Todd G Williams, PE >> >> Fire Protection Design/Consulting >> >> Stonington, CT >> >> 860-535-2080 (ofc) >> >> 860-554-7054 (fax) >> >> 860-608-4559 (cell) >> >> _________________________________________________________ >> SprinklerForum mailing list: >> >> https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org >> To unsubscribe send an email to >> [email protected] >> > > _________________________________________________________ > SprinklerForum mailing list: > https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org > To unsubscribe send an email to > [email protected]
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