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Which of the following is true about a "dry pi…

Which of the following is true about a “dry pipe” sprinkler system?

PrepAway - Latest Free Exam Questions & Answers

A.
It is a substitute for carbon dioxide systems.

B.
It maximizes chances of accidental discharge of water.

C.
It reduces the likelihood of the sprinkler system pipes freezing.

D.
It uses less water than “wet pipe” systems.

Explanation:
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. Water is not allowed into the pipes that feed the sprinklers
until an actual fire is detected. First, a heat or smoke sensor is activated; then, the water fills the pipes leading
to the sprinkler heads, the fire alarm sounds, the electric power supply is disconnected, and finally water is
allowed to flow from the sprinklers. These pipes are best used in colder climates because the pipes will not
freeze.
Incorrect Answers:
A: A “dry pipe” sprinkler system is not a replacement for a carbon dioxide system. Dry pipe systems still use
water which is not suitable for many fires. Therefore, this answer is incorrect.
B: A “dry pipe” sprinkler system does not maximize the chances of accidental discharge of water. The chances
are reduced as there is no water held in the pipes. Therefore, this answer is incorrect.
D: A “dry pipe” sprinkler system uses no less water than “wet pipe” systems. Therefore, this answer is incorrect.

Harris, Shon, All In One CISSP Exam Guide, 6th Edition, McGraw-Hill, 2013, p. 474


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