What type of nozzle is designed to maintain a constant pressure regardless of the flow rate?

The automatic nozzle is specifically designed to maintain a consistent pressure regardless of the flow rate. This is achieved through an internal mechanism that adjusts the opening size of the nozzle in response to the pressure in the system. When the flow rate increases or decreases, the nozzle automatically adjusts to ensure that the pressure remains stable. This feature is especially important in firefighting and other applications where maintaining a specific pressure is crucial for effective operation and to ensure the safety of the personnel using the equipment.

In contrast, the other types of nozzles do not have this capability. For instance, a fog nozzle is primarily used to create a fine mist for cooling and suppression but does not maintain constant pressure under varying flow conditions. A standard nozzle typically relies on a fixed opening and may experience pressure fluctuations based on the flow rate. A combination nozzle can switch between various flow patterns but again does not inherently stabilize pressure across flow rate changes. These characteristics highlight why the automatic nozzle is the most effective choice for applications requiring constant pressure management.