Storage sprinklers work in one of two ways. ESFR (early suppression, fast response) sprinklers are suppression mode: they are built to knock a storage fire down early, and Tyco notes they are primarily used for ceiling-only protection, so in-rack sprinklers can be left out for the listed materials and heights. Control mode sprinklers aim to control a fire and limit its spread rather than suppress it; CMDA (control mode density area) designs set a water density over an area, while CMSA (control mode specific application) sprinklers follow specific NFPA 13 criteria for high-piled storage.
For ESFR, the K-factor drives the pressure needed at the last sprinkler. Tyco offers K14.0 (ESFR-1, ESFR-14), K16.8 (ESFR-17), K22.4 (ESFR-22), K25.2 (ESFR-25) and K33.6 (ESFR-34). Tyco states the ESFR-17 works at lower end head pressures than K14.0 ESFR, and the ESFR-25 lower than both K14.0 and K16.8, which gives flexibility in pipe sizing and may reduce or remove the need for a fire pump. The ESFR-22 and ESFR-25 can protect specific materials without in-rack sprinklers up to 40 ft of storage under a 45 ft ceiling (NFPA) or 45 ft under 50 ft (FM), and the ESFR-34 up to 50 ft under 55 ft. Choose the upright ESFR-17 where pipes must run below the ceiling, and the dry-type ESFR-17 or ESFR-25 for freezers.
Large orifice control mode sprinklers suit storage that does not use ESFR. The K11.2 ELO-231, ELO-231B, ELO-231FRB, K11-231B and K11-231FRB were fire tested to replace K5.6 or K8.0 standard spray sprinklers over high-piled storage, and the K16.8 K17-231 to replace K8.0 or K11.2; Tyco notes they give higher flow at lower pressure. The Ultra K17 and LD (large drop) are for CMSA designs, the Ultra K34 for dry pipe or preaction systems over Class III commodities, and the EC-25 is an extended coverage CMDA sprinkler covering up to 196 sq ft. The TY7158 and TY7258 are specific use retrofit sprinklers, and the TY720 is the electronically operated sprinkler of Tyco's EAS-1 system.
Intermediate level sprinklers go inside the racks, with a shield that keeps water from higher sprinklers off their heat sensitive element; Tyco offers them in the TY-L, TY-B, TY-FRL and TY-FRB series, and the K11.2 lines become intermediate level versions with a guard and shield. Approvals differ by data sheet, so match them to your NFPA 13 or FM Global design. FPS supplies, installs and maintains Tyco storage sprinklers in Bhopal and across MP.