in the same fashion as the ESFR sprinklers, requiring a “12 head” design for the system water demand, identical hose stream demand and water supply duration. The same sprinkler installation rules with regard to physical obstructions and ceiling elements are applied to both the ESFR pendent sprinklers and the new sprinkler. However, because it does not use a fast-response link, the new sprinkler is being classified not as an ESFR sprin- kler but as a CMSA sprinkler. This type of technology can offer a significantly
alone is not the necessary and sufficient condition for a sprinkler system to achieve fire suppression. More importantly, it is the condition where ADD is greater than RDD and where superior fire suppression can be expect- ed.
A new large K-factor standard-response sprinkler has
been developed that can now achieve fire suppression of cartoned plastic commodities under a ceiling up to 40 ft high. The sprinkler model is a pendent sprinkler with a nominal one-inch diameter orifice and a K-factor of 25.2. A series of fire tests concluded that the standard-
response K 25.2 sprinkler can be as effective as ESFR sprinklers in providing protection for storages in ware- houses with ceiling height up to 40 ft, since both the ESFR sprinklers and the new sprinkler were evaluated with the same fire scenarios. Based on the performance of the new sprinkler, FM Global has treated the sprinkler
Product innovation The FireLock® LP-46 Low Pressure Upright
Storage Sprinkler from Victaulic is FM Approved for up to 40 foot ceilings to protect up to cartoned expanded and unexpanded plastic commodities. This new proprietary design offers a signifi- cantly reduced end-head pressure as compared to traditional ESFR technolo- gy and is poised to replace ESFR as the design standard in high ceiling storage applications. Further, this new sprinkler can reduce diameters in branch lines and potentially reduce or eliminate pump size, affording significant cost savings in mater- ial and labor. The LP-46 Upright Sprinkler pro-
vides a robust conventional standard response fusible link and a 25.2 K-Factor, distributing water in a pattern that covers 100 square feet per sprinkler. System design for the LP-46 is based upon straight forward 12-head calculations, and can result in the need for up to 20 percent fewer sprinklers in a given system, further adding to the cost savings over traditional technologies.
Plumbing Engineer
reduced end-head pressure as compared to traditional ESFR technology and is poised to replace ESFR as a design choice in storage applications. A benefit of the reduced end-head pressure of this new storage sprinkler is the opportunity to reduce pipe diameters in branch lines and cross mains and, potentially, even to eliminate the need for a pump, if the public water supply is strong enough, affording significant cost savings in material and labor.
Moving forward The needs for adequate fire protection continue to
grow in the storage environment as these spaces grow taller and broader and as racks are built higher. A broad- er variety of materials with different levels of flammabil- ity are now being stored, requiring a wider range of fire protection solutions. Complex installation guidelines for each class of sprinklers further complicate the design landscape. In 2010, FM Global began an update of its data sheets
that specifies the rules for system design and installation for storage sprinkler systems. The goal is to simplify the variations in sprinkler classes and to base the system design rules on performance of the sprinkler, not on the traditional names of the sprinkler. Hence, greater consis- tency in system performance can be obtained. The fire suppression or control performance of sprin-
klers depends on the combined effects of the sprinkler attributes: sprinkler orientation (pendent or upright), sprinkler deflector design for generating the desirable spray pattern, volume median diameter of the spray, sprinkler sensitivity (RTI) and temperature rating. FM Global’s new data sheets base the system design rules on performance of the sprinkler rather than on the tradition- al name associated with the sprinkler. This sprinkler per- formance is predictable, based upon the parameters of the system. As storage space design continues to evolve, new tech-
nologies continue to be introduced into the marketplace to meet increasing challenges. n
Dr. H.C. Kung is the research director at Victaulic and
a Fellow of the Society of Fire Protection Engineers. His career spans more than 35 years with Factory Mutual and Underwriter’s Laboratory, where he drove develop- ment of residential, quick response, ESFR, Extra Large Orifice, ESFR upright and K17 large drop sprinkler tech- nologies.
February 2011/Page 37
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