Didn't matter on Jim's - pump and tank. Assume air gap, since tank non-potable. So drilled check is fine- except when water replaces what dribbled out.
As for dry vrs AF, can't use CPVC with dry; dry pend are $$$ and may not fit in small space allotted; in 13d the unlisted bladder is $75, so what= put it in! We've done a lot of AF systems just so we could make an installation practical- i.e, rather CPVC/AF than dry with steel, drains and couplings every 2'. glc -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Matt Grise Sent: Thursday, January 21, 2010 2:41 PM To: '[email protected]' Subject: RE: Antifreeze Backflow Prevention Sorry...unclear wording. I meant that you could use either: 1) an RPZ at the riser, and a drilled check valve at the loop 2) a double check bfp at the riser and an RPZ at the loop We sometimes use the second setup since RPZ's cost so much more than DC BFP's. If the primary riser is 4,6,8" and the antifreeze loop only needs a 1.25" RPZ, it can be less expensive to use 2 bfp's. Matt Grisé PE*, LEED AP Sales Engineer Alliance Fire Protection *Licensed in KS & MO 913.888.0647 ph 913.888.0618 f 913.927.0222 cell www. AFPsprink.com -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Roland Huggins Sent: Thursday, January 21, 2010 1:38 PM To: [email protected] Subject: Re: Antifreeze Backflow Prevention What's your basis for requiring two backflow prevention devices? You can use the U-loop with the drilled check valve on the antifreeze system w/o a BFP but then your backflow protection between the sprinkler system and the potable water can no longer be just a double check BFP but must be a reduced-pressure type. Roland On Jan 21, 2010, at 8:25 AM, Matt Grise wrote: > You are correct. There needs to be backflow protection between the > public/domestic supply and the sprinkler system, and also between > the wet system and the antifreeze loop. > > Matt Grisé PE*, LEED AP > Sales Engineer > Alliance Fire Protection > *Licensed in KS & MO > _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
