What happens to steam as it enters the dry pipe?

When steam enters the dry pipe, it undergoes a process where it changes direction and separates impurities. This is due to the design of the dry pipe system, which is specifically created to allow for a separation of the steam from any moisture and particulates that may have been carried along with it.

The change in direction helps facilitate this separation, as centrifugal forces are applied, allowing heavier water droplets or impurities to migrate away from the steam flow. The primary purpose of the dry pipe is to ensure that only dry steam, free from contaminants, is delivered to the intended process or application. This is crucial in preventing issues that can arise from the presence of water or impurities, such as corrosion, reduced efficiency, or damage to equipment.

In contrast to the other choices, the correct option accurately reflects the operational principle of a dry pipe system where the focus is on maintaining a high-quality steam supply. The other options touch on different phenomena that don't accurately represent the function of a dry pipe in a steam system.