Chapter 26 (3 of 3)

The clapper assembly located inside most dry pipe valves relies on

• temperature differential
• flow differential
• volume differential
• pressure differential

ON a dry pipe system, to maintain the pressure differential, which side of the clapper valve has the large size pipe

• Air
• Solid

• Oil
• Water

When should a dry pipe sprinkler system be drained to prevent freeze breaks

• In the fall and through winter (Potential for moisture buildup)
• Only when the system is malfunctioning (Risk of damage)
• Once a month (Regular maintenance)
• In the spring and summer (No risk of freezing)

What a causes an accelerator (dry pipe) to activate

• Gradual drop in air pressure
• Sudden increase in air pressure
• Rapid drop in air pressure
• Stable air pressure

What does an exhauster do in a dry pip sprinkler system

• Close the water supply
• Open a large-diameter portal to allow air out
• Increase water pressure
• Activate the alarm system

An accelerator allows

• Air pressure to flow to the exhaust side of the clapper valve
• Air pressure to flow to the supply side of the clapper valve
• Air pressure to flow to the opposite side of the clapper valve
• Air pressure to flow to the inlet side of the clapper valve

A single interlock preaction system uses

• unpressurized air
• foam
• water
• pressurized air

A double interlock preaction system uses

• Carbon dioxide
• Pressurized water
• Oxygen
• Pressurized air or nitrogen

What is the benefit of a preaction valve

• Preaction valve increases fire risk
• Sprinkler won't be triggered by damage
• Sprinkler will be triggered by damage
• Preaction valve reduces water pressure

Deluge sprinklers must have

• Frozen pipes
• Wet pipes
• Leaking pipes
• Dry pipes