Operator`s manual

MAINTENANCE MANUAL
SECTION 3
3. PUMP ASSEMBLY
3.1 GENERAL DESCRIPTION
The pump assembly consists of a Hale centrifugal, single-stage pump with power shift and electric
priming, and a pump control panel. Also included are miscellaneous items such as an automatic pump
relief valve, a foam system, suction and discharge valves and couplings and drain valves. Power for the
operation of the pump is provided by the engine through the drive shaft linkage. Power is transferred from
the truck drive train to the pump by operating the pump control valve in the cab. The paragraphs that
follow describe the operation of the water system. The numbers in brackets refer to locations on Figure 3-
1, "Water Plumbing Schematic".
3.2 OPERATING MODES
The pump is designed to pump up to 200 psi. Generally, there are three modes of operation: Hydrant,
Static Water Supply and Water Tank. In the Hydrant mode the suction side of the pump is connected to a
hydrant source, or an external source such as a second pumper. In the Static mode the suction side of
the pump is connected through a suction hose to a static water supply, such as a stream, pond or storage
tank. In the Water Tank mode the pump utilizes the water stored on the truck.
9