What occurs when small amounts of air collect in piping, leading to air locking?

When small amounts of air collect in piping, they can create what is referred to as air locking. This phenomenon typically occurs in systems where liquids, such as water, are intended to flow through the pipes. The presence of a bubble of air can obstruct the passage of the liquid, as the air bubble occupies space within the pipe and creates a blockade. Therefore, the primary concern is that this air bubble effectively prevents the smooth flow of water, leading to disruptions in the system's operation.

Although reduced system efficiency is a consequence of air locking, the defining characteristic of the issue is the blockage created by the air bubble itself. Excessive heat generation can occur in some systems as a result of inefficiencies, but it is not a direct result of air locking. Similarly, increased water velocity is generally not associated with the presence of air and could actually decrease due to the blockage caused by air in the piping system. The core concept lies in the fact that air locking directly inhibits fluid movement, which is accurately captured by the correct answer.