What is the purpose of an air blowout in a standpipe system installed on floating marinas?

• A. To purge air pockets during testing
• B. To prevent freezing of the piping system
• C. To increase water velocity
• D. To vent corrosive gases

Answer: (B)

The main idea is winterizing the standpipe so it won’t be damaged by freezing. An air blowout is used to push water out of the piping and fill the lines with air, which prevents remaining water from freezing and expanding inside the pipes on floating marinas. This keeps the system protected during cold weather and makes it easier to reoccupy or test later.

Air blowouts aren’t primarily about venting air pockets during normal testing—that function is handled by air-release vents at high points. Nor is it intended to increase water velocity or to vent gases as a normal purpose in marina standpipes.