Holmatro DPU31 Manual Del Propietário página 9

8. Operation
The oil from the hydraulic pump is supplied to the tool via high-pressure hoses. The oil returns at
atmospheric pressure to the pump if the tool dead-man's handle is in the neutral position.
Tool Control Handle decal.
Oil is admitted under the tool piston if the dead-man's handle is in the "open" position. The tool will then
open. The oil above the piston flows back to the pump.
Oil is admitted above the tool piston if the dead-man's handle is in the "close" position. The tool will
close. The oil under the tool piston flows back to the pump.
The tool dead-man's handle always returns to the neutral position when released.
CORE™ TOOLS & PUMPS
The hydraulic system in the unit is provided with a safety valve. This safety valve prevents excessive
pressure in the tool if the return line to the pump is blocked. Never change the setting of this safety valve.
Oil will discharge from the rear of the tool if the return hose becomes blocked while the pump is running.
If this happens, first switch the pump engine/motor to OFF and disconnect the hose. Then connect a new
hose.
When Holmatro valve blocks are mounted on your Holmatro power unit, the manual operated
release valve is no longer needed. As soon as the hose is connected, oil is flowing through the hose's inner
shell and returning back to the tank of the pump through the hose's outer shell. When a rescue tool with
the adaptor installed has been connected to the hose, oil will flow into the tool. To change from
one rescue tool to another, the user simply disconnects the rescue tool from the hose and connects the
alternate rescue tool to the hose. Oil always flows from the female coupler into the male coupler for
Holmatro systems.
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