Question 57

Explanation

Correct Answer:

B is correct. In a preaction water sprinkler system, a thermal-fusible link on the sprinkler heads must melt before the water will pass through the sprinkler heads, which creates the delay in water release. This type of suppression system is best in data processing environments because it allows time to deactivate the system if there is a false alarm. 

Incorrect Answers:

A is incorrect. A wet pipe system always contain water in the pipes and is usually discharged by temperature control–level sensors. 

C is incorrect. A deluge system has its sprinkler heads wide open to allow a larger volume of water to be released in a shorter period. Because the water being released is in such large volumes, these systems are usually not used in data processing environments. 

D is incorrect. In dry pipe systems, the water is not actually held in the pipes. The water is contained in a “holding tank” until it is released. The pipes hold pressurized air, which is reduced when a fire or smoke alarm is activated, allowing the water valve to be opened by the water pressure.