Dry pipe sprinkler systems are charged with which of the following?

Dry pipe sprinkler systems are charged with which of the following?

• A. Air
• B. Water
• C. Steam
• D. Oxygen

Answer: (A)

Dry pipe sprinkler systems are kept dry by precharging the piping with air under pressure. This air acts as a barrier that holds back the water until a sprinkler head is activated. When a head trips, the dry-pipe valve releases and water from the supply moves into the pipes, pushing the air out and filling the lines to deliver water to the heads. Using air prevents the pipes from filling with water in cold conditions, reducing the risk of freezing and damage. Steam isn’t used because it’s not practical for this purpose, and oxygen would cause corrosion and isn’t the normal charging medium. Water would defeat the whole point of a dry system. So, the system is charged with air.

Dry pipe sprinkler systems are kept dry by precharging the piping with air under pressure. This air acts as a barrier that holds back the water until a sprinkler head is activated. When a head trips, the dry-pipe valve releases and water from the supply moves into the pipes, pushing the air out and filling the lines to deliver water to the heads. Using air prevents the pipes from filling with water in cold conditions, reducing the risk of freezing and damage. Steam isn’t used because it’s not practical for this purpose, and oxygen would cause corrosion and isn’t the normal charging medium. Water would defeat the whole point of a dry system. So, the system is charged with air.