2-4 Automatic Pressure Control DevicesAutomatic Pressure
Control Devices
Types of Devices
Pressure relief valves
Pressure governor
Purpose
Control excessive pressure
Protects fire fighters and equipment from water
hammer
Works on the principle of pressure differential
Discharge Pressure Relief Valve
OPERATION
Pressure side of the pump to the inlet
Adjustable
Components
Pilot valve/controller
Four-way valve
Relief valve
Four-way valve
Pilot valve
Discharge Pressure Relief Valve
Intake Pressure Relief Valve
OPERATION
Excess pressure from the supply line
Some not easily adjustable
External to pump panel or internal on pump
External Relief
Valve
Internal Relief
Valve Control
Pressure Governor
PURPOSE
Controls excessive pressure
Protects fire fighters and equipment
OPERATION
Opening and closing the throttle to the engine
Electronic
Manual
Pressure
Governor