Comparative Study on the Spray Characteristics of Bottom-Up Sprinkler Heads

Bottom-up sprinkler heads are typically installed in parking lots of buildings and in places without a semi-finished ceiling. However, bottom-up sprinkler heads that comply with domestic fire codes can exhibit water spray performances depending on the manufacturer. In this study, we compare the spray characteristics of bottom-up sprinkler heads manufactured by five different vendors in Korea by conducting a waterproof amount test, spray distribution test, and spray pattern analysis. The results of the waterproof amount test indicated that all sprinkler head samples showed minimum and maximum deviations of 0.02 and 1.11, respectively, from the reference K-factor of 80; these deviations were within the allowable range specified in the relevant regulations. Further, the spray distribution test results indicated that all sprinkler head samples satisfied the three performance criteria specified in the relevant regulations, the radial spray distribution showed differences, and two distinct spray patterns (one that wets the ceiling and another that does not) were observed.