Which component is always under pressure in an irrigation system?

The main line in an irrigation system is designed to always be under pressure because it is the primary conduit through which water is delivered from the source to the various parts of the irrigation network. This constant pressure is crucial for ensuring that water can effectively reach the locations where it is needed, thus providing consistent coverage for the landscape or crops being irrigated.

Maintaining pressure in the main line is essential for the proper operation of the system, allowing for the effective distribution of water through the lateral piping and to the emitters or sprinkler heads. If the main line did not maintain pressure, it would hinder the entire irrigation process, leading to inadequate watering and potential stress on the plants.

While other components, such as the master valve, lateral piping, and isolation valves, may experience pressure during system operation, they are not always under constant pressure like the main line. The master valve may remain closed during system inactivity; lateral piping experiences variations in pressure based on water flow, and isolation valves are typically used to restrict or control water flow in specific areas at certain times. Therefore, the main line's continuous pressure is what distinguishes it as the component always under pressure.