Thermal bypass outlet

Pressure Washer Familiarization and Troubleshooting Guide Section 1 • Operation

PRESSURE WASHER OPERATION

Operation of a pressure washer system may be briefly described as follows. Please refer to Figure1.1 for visual component identification: 1. An inlet hose delivers water to the motor-driven, pistontype pump. An inlet strainer (item 6) protects the pump (item 5) against damage from solid impurities. The motor driving the pump (item 9) may be gas or electric.

Figure 1.1 — Example Pressure Washer System 2. Rotary motion of the motor crankshaft is converted to reciprocating motion of the pump’s pistons using an axial cam. On a piston’s ‘suction’ stroke, an inlet valve opens and water is drawn into the piston chamber. On the piston’s ‘pressure’ stroke, that piston’s inlet check valve closes and its outlet check valve is forced open so pressurized water can leave the chamber. There is one inlet check valve and one outlet check valve for each piston.

Item Name 1 Spray nozzle 2 Hi-Lo nozzle collar 3 Spray gun extension wand 4 Spray gun with locking trigger 5 Pump, including optional thermal relief and/or easy start valve Item Name 6 Inlet strainer 7 Unloader/pressure regulator valve 8 Chemical inject fitting (optional) 9 Engine on cart 10 High pressure hose