In which type of sprinkler system does air or nitrogen under pressure replace the water in the sprinklers above a valve?

Question

Quizplus · Accepted Answer

In a dry-pipe sprinkler system, air or nitrogen under pressure is used to fill the pipes instead of water. This type of system is used in places where the water in the pipes could freeze, as the pressurized air or nitrogen holds a remote valve, known as a dry pipe valve, in a closed position. Water does not enter the piping until the air pressure is released, which happens when a fire activates one or more sprinklers.

In Which Type of Sprinkler System Does Air or Nitrogen