What is the primary purpose of high-point vents during hydrotesting?

• A. To vent water
• B. To purge air pockets
• C. To measure temperature
• D. To relieve pressure

Answer: (B)

In hydrotesting, the goal is to fill the system completely with water and pressurize it to verify integrity. Air trapped inside can block full water fill and create unreliable readings. Placing vents at the highest points takes advantage of gravity: air, being lighter than water, rises to the top, where these vents let it escape. By purging the system of air pockets, you achieve a uniform water fill and accurate pressure testing. Temperature measurement isn’t the role of these vents, and relieving pressure is handled by other safety devices; the vents’ primary job is to remove trapped air.