Airo A Series - Circuit Movements Pressure Relief Valve Operation Check; Pressure Relief Valve of Proportional Movement Circuit

Use and Maintenance Manual – A12 JE A15 JE A17 JE A12 JED A15 JED
Series
Page 65
7.2.7. Circuit movements pressure relief valve operation check
7.2.7.1. Pressure relief valve of proportional movement circuit
The pressure relief valve described controls
the maximum pressure on the circuit of
proportional movements (pantograph, upper
boom, telescopic boom, jib, turret rotation, jib
rotation). Normally, this valve does not
require any adjustment, since it is calibrated
at the factory before the machine is
delivered.
Calibration is required:
▪ in case of replacement of the
hydraulic block
▪ in case of replacement of the
pressure relief valve only.
Check operation at least once a year
Fig. 23
To check the operation of the pressure relief valve:
▪ Introduce a pressure gauge with full scale of at least 250 bar in the special quick coupling (1/4” BSP) A;
▪ Using the ground control panel, lift the pantograph (lower boom) up to the end stop.
▪ Check the pressure value. The correct value is indicated in the chapter “Technical features".
To calibrate the pressure relief valve:
▪ Introduce a pressure gauge with full scale of at least 250 bar in the special quick coupling (1/4” BSP) A;
▪ Locate the pressure relief valve of lifting circuit B;
▪ Unscrew the adjusting dowel lock-nut.
▪ Using the ground control panel, lift the pantograph (lower boom) up to the end stop.
▪ Adjust the pressure relief valve by means of the adjusting dowel so as to reach the pressure value indicated in
chapter "Technical Features".
▪ Once calibration has been carried out, lock the adjusting dowel by means of the lock-nut.
WARNING!
AS THIS OPERATION IS VERY IMPORTANT IT IS TO BE CARRIED OUT BY SKILLED TECHNICIANS
ONLY.
A
B