Table of Contents
Advertisement
1. The main release prevents the working pressure to rise too
high. There is one on each pressure control valve over each
pressure connection. If the pressure of oil coming to the control
valve exceeds the set value, oil will be discharged to the tank
channel until the set pressure level has been reached once
again.
2. Cylinder-specific pressure relief valves prevent the pressure
to rise too high in different cylinders. If the cylinder exceeds the
set pressure value, oil will be discharged from the cylinder
through the pressure relief valve until the permitted pressure
value has been reached.
3. Throttle check valves are used in swing, lift, and transfer cyl-
inders. They regulate the travel speed of the booms so that the
speed is adequate and the corresponding cylinders get enough
filling oil from the pump.
* NOTE!
The check valve's adjustment should be done
when unpressurised(Pump has been switched off); the valve
can become damaged.
4. The stabilizer legs are equipped with pressure-controlled
check valves (lock valve). They prevent the legs from collapsing
in case of a possible overload or hose failure.
5. A swing, lift, and transfer cylinder can be equipped with an
overcenter valve, if necessary. It locks the load into the desired
position and prevents the load from falling in case the hose
breaks. The load's descent takes always place in a controlled
way.
2.3.3 Emergency stops
he crane's control system must be equipped with a STOPswitch located in the crane's control posi-
tion. It can be used to cut off crane's oil supply (e.g. by an electrically controlled valve) or, alterna-
tively, the electric current to the pilot-operated control valve. Also the stopping of the drive unit is
considered as a STOP- operation, if it can be done from the control position.
2.3.4 Priorities and dimension drawings
More detailed device-specific information can be found in the booklet's APPENDIXES (10)
SAFETY INSTRUCTIONS
13
Advertisement
Table of Contents
