Structure and parts of the HIAB crane
2.5
2.5
Operating system - hydraulic
components
The operating system consists of the following
hydraulic components:
• oil tank
• hydraulic pump
• oil cooler [option on some cranes]
• main control valve
• stabiliser control valve [option on some
cranes]
• hydraulic hoses and lines
• actuators:
first boom cylinder
second boom cylinder
extension cylinder/s
slewing cylinders / motor reducers
• return filter
• pressure filter [option]
2.6
LHV Load holding valves
All cylinders are equipped with load-holding
valves as a safety device. After a crane move-
ment they hold the crane in position, also in the
unlikely event of a burst hose.
If there is a leak or a component fractures, such
as a pipe, hose or a coupling, the load-holding
valves will stop the booms from collapsing down,
even when the hydraulic system is switched off,
and you operate a particular crane function.
To operate a hydraulic cylinder equiped with a
load holding valve, an opening pressure is re-
quired.
Operator's Manual GB
13