Water droplets entrained in steam leaving the boiler are referred to as what?

• A. Priming
• B. Blowdown
• C. Flash steam
• D. Scavenging

Answer: (A)

Priming is the term for water droplets carried along with steam as it leaves the boiler. This happens when the boiler contains too much moisture, or when steam is produced so rapidly that liquid water isn’t fully separated from the vapor before it exits the drum. The result is wet steam, which can carry droplets into turbines or condensers, reducing efficiency and causing wear.

This is different from blowdown, which is deliberate removal of water to control impurities; from flash steam, which is steam formed when hot liquid is released to a lower pressure; and from scavenging, which relates to removing unwanted gases or liquids from another part of the system.