15
Structure and parts of the HIAB crane
Operator's Manual GB
2.8
2.8
Operating system - hydraulic
components
The operating system consists of the following
hydraulic components:
• oil tank
• hydraulic pump
PTO or a 12V/24V motor
• Main control valve
• hydraulic hoses and pipes
• actuators:
first boom cylinder
extension cylinder/s
• filter/s
2.9
LHV Load holding valves
The cylinder is equipped with a load-holding
valve. After a crane movement it holds the crane
in position.
If there is a leak or a component fractures, such
as a pipe, hose or a coupling, the load-holding
valve will stop the boom from collapsing down,
even when the hydraulic system is switched off,
and you operate a particular crane function.
To operate a hydraulic cylinder equipped with a
load holding valve, an opening pressure is re-
quired.