-
Pounds Per Square
Inch
(psi) is the measurement of water pressure. The
greater the psi, the better the cleaning efficiency.
-
Gallons Per Minute
(GPM) refers to the water flow rate. Look for a
combination of psi and GPM to deliver cleaning power. High
pressure with little water flow is not effective.
-
Cleaning Unit
(CU) is the water pressure multiplied by the water flow. A
higher number means more power.
-
Gasoline engines are
measured in horsepower (HP).
More HP equals more
power.
-
Electric motors are
measured in
amperage (amps).
More amps
equals more power.
-
Direct drive
is a
shaft driven pump directly off the engine or motor.
Requires less maintenance although when something does go
wrong, typically more expensive to fix.
-
Belt drive
uses a
set of pulleys and a v-belt or a cogged belt to drive the
pump. Although belts can break, they are less prone to
expensive mechanical repairs.
-
Plunger type
pumps
typically have high-pressure capability with great serviceability
and pump life. More plungers results in a smoother flow.
-
Radial axial
pumps are usually lower pressure pumps used on
lighter-duty equipment.
-
The nozzle
or tip
of the washer does the actual cleaning work. The spray
angle of the nozzle is adjustable to fit the cleaning
need. The wider the spray, or fan, the lower its ability
to cut through dirt. A zero-degree nozzle provides intense
power. Fan angles of 15 to 25 degrees cover larger areas,
combining stripping and washing power. Fans of 40 degrees
or more are generally used for simple washing. Rotating
nozzles (also called turbo nozzles) are used for heavy
duty cleaning applications.
