What is an important characteristic of eccentric fittings in plumbing?

Eccentric fittings are specifically designed to facilitate proper drainage within a plumbing system. These fittings allow for an offset connection between two pipes that may not be aligned perfectly. By offering different diameters and angles, eccentric fittings ensure that the flow of water can efficiently navigate through the system without creating traps or stagnation points that could impede drainage.

In the context of the other choices, while pressure zones, alignment of pipes, and regulating pressure are important plumbing considerations, eccentric fittings primarily focus on enhancing the efficiency of fluid movement and proper drainage in a system. Their design helps to maintain a smooth flow path, which is critical for preventing water from pooling or leaking, thereby promoting effective drainage throughout the plumbing infrastructure.