NFPA 13 does not REQUIRE 1” outlets for shell spaces. However, it is good practice.
I would not include a bushing in my calcs nor would I ever expect greater than a 11.2 k sprinkler in a buildout – at least in the SE part of the country. Greg McGahan Genesis Fire Services, LLC o-850-637-8535 From: Sprinklerforum <[email protected]> On Behalf Of Kyle.Montgomery via Sprinklerforum Sent: Wednesday, February 5, 2020 10:07 AM To: [email protected] Cc: Kyle.Montgomery <[email protected]>; Bruce Verhei <[email protected]> Subject: RE: [EXTERNAL] Re: Shell Spaces and Bushed Outlets Yeah, for the first part of my question about 8.15.20, I agree. But I realize that the easy answer there is that the tee probably makes little difference, so why not just include it in the calc. So I figured I would spice it up since we actually do run into this type of scenario from time to time. So it’s really two questions that can be considered independently: 1. Does NFPA 13 require minimum 1” outlets in shell spaces? 2. If I have a sprinkler installed in a bushed outlet, do I need to include the equivalent length for that tee in my calculations. -Kyle M From: Sprinklerforum [ <mailto:[email protected]> mailto:[email protected]] On Behalf Of Bruce Verhei via Sprinklerforum Sent: Wednesday, February 5, 2020 9:01 AM To: <mailto:[email protected]> [email protected] Cc: Bruce Verhei < <mailto:[email protected]> [email protected]> Subject: Re: [EXTERNAL] Re: Shell Spaces and Bushed Outlets K-17. That’s a little different than I expect. I always thought more like parts of a strip mall building that might end up OH-2. Best. On Feb 5, 2020, at 07:58, Kyle.Montgomery via Sprinklerforum <[email protected] <mailto:[email protected]> > wrote: That’s the crux of my question. A literal interpretation could say that the sprinkler is no longer connected directly to the tee, so you have to include the equivalent length for the tee in the calculations. But is that really the intent in this scenario? Is the bushing really creating an impact to the hydraulics? It seems strange to me that the type of fitting the sprinkler is connected to (welded outlet, threaded tee, threaded elbow) is of no concern to the hydraulics, unless the fitting has a bushed outlet. Does a threaded tee with a bushing really create more friction loss than, say a saddle tee (mechanical tee)? In a lot of cases it doesn’t make much of a difference, but every once in a while you run into a scenario where you’re upgrading an area that had 1” outlets to something that needs a large orifice sprinkler (like a K17) and if you have to add the friction loss for a 1” tee into your calc it really does have an impact. -Kyle M From: Sprinklerforum [ <mailto:[email protected]> mailto:[email protected]] On Behalf Of J H via Sprinklerforum Sent: Tuesday, February 4, 2020 3:41 PM To: <mailto:[email protected]> [email protected] Cc: J H < <mailto:[email protected]> [email protected]> Subject: [EXTERNAL] Re: Shell Spaces and Bushed Outlets That doesn't sound legit - I would keep the tee in the calculations. A bushing isn't really recognized as a fitting per table 23.4.3.1.1 - more like a transient fitting. On Tue, Feb 4, 2020 at 1:22 PM Kyle.Montgomery via Sprinklerforum <[email protected] <mailto:[email protected]> > wrote: Esteemed members of the fire sprinkler community, NFPA 13 (2016 Edition) section 8.15.20 is basically telling us to provide bushed 1” outlets for sprinklers in shell spaces, right? Section 23.4.4.8.1(9) tells us that friction loss can be excluded for the fitting directly connected to a sprinkler. In your opinion(s), is it the intent of the standard that you have to add the friction loss for a tee into your hydraulic calculation if using bushings, since the sprinkler is no longer directly connected to the tee? Or is it acceptable to consider a tee with a bushing as one fitting for the purpose of hydraulic calculations. Kyle Montgomery <image001.png> Aero Automatic Sprinkler Co. 21605 N. 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