Wiki Pages

Category: terms-definitions

  • Pump Capacity Rating

    Maximum amount of water a pump will deliver at the indicated pressure.

  • Pump Charts

    Charts carried on a fire apparatus to aid the pump operator in determining the proper pump discharge pressure to use when supplying hoselines.

  • Pump Discharge Pressure (PDP)

    Actual velocity pressure (measured in psi) of the water as it leaves the pump and enters the hoseline.

  • Pump Drain

    Drain located at the lowest part of the pump to help remove all water from the pump. This eliminates the danger of damage due to freezing.

  • Positive Displacement Pumps

    Self-priming pump that moves a given amount of water or hydraulic oil through the pump chamber with each stroke or rotation. These pumps are used for hydraulic pumps on aerial device hydraulic systems and for priming pumps on centrifugal fire Read on! →

  • Pounds per Square Inch (psi)

    Customary unit for measuring pressure.

  • Power Take-Off (PTO)

    Rotating shaft that transfers power from the engine to auxiliary equipment.

  • Preconnect

    (1) Attack hose connected to a discharge when the hose is loaded; this shortens the time it takes to deploy the hose for fire fighting. (2) Soft intake hose that is carried connected to the pump intake.

  • Preservice Tests

    Tests performed on fire pumps or aerial devices before they are placed into service. These tests are broken down into manufacturer’s tests, certification tests, and acceptance tests.

  • Pressure

    Force per unit area measured in psi or kPa.

  • Pressure Governor

    Pressure control device that controls engine speed and therefore eliminates hazardous conditions that result from excessive pressures.

  • Pressure Operation

    Operation of a two- (or more) stage centrifugal pump in which water passes consecutively through each impeller to provide high pressures at a reduced volume.