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]] On Behalf Of J H via Sprinklerforum Sent: Tuesday, February 4, 2020 3:41 PM To: [email protected] Cc: J H <[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 [cid:[email protected]] Aero Automatic Sprinkler Co. 21605 N. Central Ave. Phoenix, AZ 85024 Direct: 623.580.7820 Cell: 602.763.4736 [email protected]<mailto:[email protected]> _______________________________________________ Sprinklerforum mailing list [email protected]<mailto:[email protected]> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org<https://urldefense.proofpoint.com/v2/url?u=http-3A__lists.firesprinkler.org_listinfo.cgi_sprinklerforum-2Dfiresprinkler.org&d=DwMFaQ&c=wn3mZQLIuInh2ClcJ0_DIA&r=Z_2A85VL7AQzoqudh6uOyS3bn8etxB7nLN8OBJwQd9A&m=22e6bKepvo8qto61arVvXlovak9BImEt5_bPcRG4570&s=BAPqmF3QDplLIxU5oBLuKNOXMAQVNSmlBkkIViUNLE4&e=>
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