That is for CMSA only. Using standard spray, you want to look at 8.6.5.2.1.8. That is the reference for smaller than 3” not needing to meet the 3x rule. For 3” and larger, you must comply with 3x rule for standard spray.
<http://www.mfpdesign.com/> Travis Mack, CFPS, CWBSP, RME-G, SET MFP Design, LLC 3356 E Vallejo Ct Gilbert, AZ 85298 480-505-9271 fax: 866-430-6107 <mailto:[email protected]> [email protected] www.mfpdesign.com Send large files to us via: <https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.hightail.com%2Fu%2FMFPDesign&data=02%7C01%7C%7C1121d49f9e6b4cf248f108d4df580e77%7C14e5497c16da42e69ffa77d19bafe511%7C0%7C0%7C636379016677342180&sdata=eGdMZGu2wXhUupGwgGTrqF3b54OP5%2BAZvlHhABSexWY%3D&reserved=0> https://www.hightail.com/u/MFPDesign LinkedIn: <https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.linkedin.com%2Fin%2Ftravismack&data=02%7C01%7C%7C1121d49f9e6b4cf248f108d4df580e77%7C14e5497c16da42e69ffa77d19bafe511%7C0%7C0%7C636379016677342180&sdata=tT5E7LsZjSmyreKi4gDCa70EWN%2BZodi%2FhbeCbHNRijI%3D&reserved=0> https://www.linkedin.com/in/travismack “The bitterness of poor quality remains long after the sweetness of low price is forgotten.” From: Sprinklerforum <[email protected]> On Behalf Of Ron Greenman via Sprinklerforum Sent: Tuesday, October 8, 2019 9:27 AM To: [email protected] Cc: Ron Greenman <[email protected]> Subject: Re: Upright Sprinkler >From the 2016 Handbook 8.11.5.2.2 Branch Lines. Upright sprinklers shall be positioned with respect to branch lines in accordance with one of the following: (1) Upright sprinklers shall be permitted to be attached directly to branch lines less than or equal to 4 in. (100 mm) nominal in diameter. (2) Upright sprinklers shall be permitted to be offset horizontally a minimum of 12 in. (300 mm) from the pipe. (3) Upright sprinklers shall be permitted to be supplied by a riser nipple (sprig) to elevate the sprinkler deflector a minimum of 12 in. (300 mm) from the centerline of any pipe over 4 in. (100 mm) nominal in diameter. Research conducted by FM Global has demonstrated that sprinklers will operate properly as long as the sprinkler is located within the required vertical distance between it and the ceiling above. In addition, testing has demonstrated that there is not a sizable reduction in actual delivered density when upright sprinklers are installed in the presence of a 4 in. (100 mm) wide object located directly below them. Sprigs or riser nipples are not necessary for upright sprinklers as long as the diameter of the pipe does not exceed 4 in. (100 mm). When an upright sprinkler is installed directly on the branch line, the branch line becomes an obstruction. As the branch line pipe size is increased, the “pipe shadow,” or area below the sprinkler that is affected, increases. Because CMSA sprinklers attack the fire, this obstruction can have a significant impact if the fire is located directly below the sprinkler and is a concern when the branch line piping is larger than 2 in. (50 mm). Many systems require larger piping to meet the hydraulic design requirements of the CMSA sprinkler. Raising the sprinkler on a riser nipple reduces the angle of obstruction by limiting the area affected by the obstruction to no more than would be created by a smaller branch line. Another approach to the problem is taken in 8.11.5.2.2(2). If the sprinkler is offset at least 12 in. (300 mm), the discharge from the sprinkler can flow under the branch line. This position eliminates the obstruction or limits the impact of the obstruction caused by the branch line so that it does not pose a significant problem. Ron Greenman [email protected] <mailto:[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-) On Tue, Oct 8, 2019 at 9:17 AM Bruce Hermanson via Sprinklerforum <[email protected] <mailto:[email protected]> > wrote: Did NFPA remove the requirement where upright sprinklers attached to pipe 3” or larger needs to be on a sprig? I remember seeing it in past editions but cannot find it in 2016. Bruce Hermanson President TSFP 47810 Galleon Drive Plymouth, MI 48170 (734) 454-1350 _______________________________________________ Sprinklerforum mailing list [email protected] <mailto:[email protected]> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
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