The Pressure Settings; Hydraulic Oil Cooling; Relief And Control Valves Of The Valve Blocks - JUNTTAN PM 20L Operator's Manual

JUNTTAN
7.4.1

THE PRESSURE SETTINGS

The pressure settings of the relief valves are made by Junttan Oy. The set values can be
seen in the hydraulic diagrams.
7.4.2

HYDRAULIC OIL COOLING

The oil from the return oil sump goes through two lines to the oil coolers and then
through to the return filters. The oil coolers fans are used with the hydraulic motors.
Hydraulic power to the motors is taken from the pilot pump. When the oil temperature
rises to + 55°C the temperature sensor energizes the solenoid valve which directs the oil
to the fan motor. There is also a manual switch for the oil coolers fans in the cab. See
Section Operator's controls. The temperature of the oil in the return oil sump is detected
by the temperature sensor, and displayed on a temperature gauge in the cab.
7.4.3

RELIEF AND CONTROL VALVES OF THE VALVE BLOCKS

At the end of each valve block there is a main relief valve, which is common to all the
functions connected to the valve block. The operating pressure of a function connected
to the valve block may be lower than the pressure set by the main relief valve or the
pressure of the function may need to be reduced for some reason. In such cases there is
one or two work port relief valves mounted on the valve block for this function in
question. For some functions it is necessary to adjust their speed. For this purpose there
is flow control restrictors mounted on the valve blocks.
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Routine service section