From what condition are all pumpers rated?

All pumpers are rated from the condition of draft because this represents the most demanding operational scenario for a fire apparatus. When a pumper is drafted, it operates by drawing water from a static source, such as a pond or a drafting tank, rather than from a pressurized source like a municipal water supply. This rating ensures that the pump can perform reliably under maximum strain, as drafting requires the pump to create a vacuum to lift water.

By using draft as the rating condition, manufacturers can guarantee that the pump will meet performance standards even in situations where access to pressurized water sources is limited. The ability to draft effectively indicates that the pump can also handle other conditions of operation, such as front suction or side suction, because these are generally less challenging than drafting from a static water source. This makes the rating during draft a critical benchmark for emergency service operations, ensuring that fire apparatus can adequately meet demands in various scenarios.