What is the total discharge pressure for Engine 3?

The total discharge pressure for Engine 3 is correctly identified as being between 60 psi and 90 psi. This range is standard for many fire engines during firefighting operations, as it provides adequate pressure for effectively delivering water to the fire scene while maintaining safety and operational efficiency.

Fire engines are designed to operate optimally within specific pressure parameters. The range of 60 psi to 90 psi typically ensures sufficient flow rates for hoses while preventing damage to the hoses and nozzle equipment that can occur at excessively high pressures. Additionally, maintaining pressure within this range allows firefighters to effectively manage hoses and adapt to different firefighting scenarios, such as when working with various types of nozzles that may have different pressure requirements.

In contrast, other ranges mentioned may fall outside of what is typical for operational safety and might not provide the necessary performance for effective fire suppression. Ranges exceeding 90 psi can lead to increased risk of equipment failure and put undue stress on the firefighters handling the hoses. Therefore, the selected range of 60 psi to 90 psi is both safe and practical for operational effectiveness.