Central Sprinkler’s New K-25 ESFR Sprinkler

The Central Sprinkler Co. of Lansdale, PA has designed a new ESFR sprinkler head with pressure requirements of up to 60% less than its ESFR predecessors. The new Ultra K-25 ESFR sprinkler head has already been accepted by Factory Mutual (FM). The pressure requirement for the old ESFR sprinkler heads (K-factor of 14) was 50 psi for 30 ft. buildings with 25 ft. high storage. The pressure required for the same storage arrangement using the Ultra K-25 can be reduced to 20 psi.

There are several advantages to the K-25 ESFR sprinkler as compared to the older K-14 ESFR sprinkler. They are as follows:

– The main advantage is the lower required pressure.

– It can eliminate the need for a pump and all of the associated pump expenses.

– The maximum deflector distance is 18 in. for the K-25 ESFR heads whereas the K-14 ESFR heads have a maximum deflector distance of 14 in.

– The K-25 ESFR heads can be used for buildings up to 45 ft. high with 40 ft. high storage, without the need for in-rack sprinklers. The K-14 ESFR heads require in-rack sprinklers in this situation.

– There is a 5 ft. incremental ceiling design criteria above 30 ft. This limits the amount of pressure required in a more user friendly manner and makes plans easier to design and review.

The remaining installation guidelines are essentially the same for both ESFR sprinklers. The technical data on the ULTRA K-25 ESFR sprinkler head is as follows:

Model: ULTRA K-25
Style: Pendent
Orifice Size: 0.93 in.
K-Factor: 25
Thread Size: 1 in. N.P.T.
Temp. Rating: 160ºF and 200ºF
Sensitivity: Quick Response
Approvals: FM

A Tentative Interim Amendment has been made in the 1998 edition of NFPA 231C to incorporate the design of the K-25 ESFR sprinkler head. Table 10-1.1 “Early Suppression Fast Response (ESFR) Sprinkler Data” allows the following design parameters:

Note: No in-rack sprinklers are required for the above mentioned design arrangements.

For more information call technical services at (800) 523-6512 – Central Sprinkler Co. of Lansdale, PA.