What occurs when priming takes place in a boiler?

• A. It fills with water completely
• B. Water particles are carried over with the steam
• C. Temperature rises rapidly
• D. The pressure decreases

Answer: (B)

When priming occurs in a boiler, it refers specifically to the situation where water particles are carried over with the steam being generated. This phenomenon happens due to a combination of factors, such as excessive cooling water, rapid steam generation, or inadequate boiler design. Essentially, the steam bubbles can become so turbulent that they carry water droplets along with them, which can lead to inefficient heating, potential contamination of the steam system, and damage to components downstream.

This is critical to understand because priming can adversely affect both the efficiency of the boiler and the safety of the overall system. Carrying water particles with steam can reduce the quality of steam, compromising processes that rely on dry steam, such as turbine operation in power plants.

The other options reflect conditions that do not accurately describe priming. While filling the boiler completely with water or a rapid increase in temperature might describe other boiler operations or malfunctions, they do not directly relate to the phenomenon of priming. Similarly, a decrease in pressure is not a characteristic of priming and could suggest a different issue altogether. Thus, understanding priming as the carryover of water with steam is essential for effective boiler operation and maintenance.