Airo A16 J Series, User Manual

Page: 73 / 128

User’s Manual – A16 J A18 J Series Page 73
7.2.9. Efficiency check of the pressure relief valve in the operating line.
The pressure relief valve controls the maximum
operating pressure (controlling lifting, descents and
slewing). Normally, this valve does not require any
adjustment, since it is calibrated at the factory before the
machine is delivered.
Calibration is strictly required:

After replacement of the hydraulics

After replacement of the pressure relief valve.
Perform a functional control of this valve at least once a
year.
To check the operation of the pressure relief valve:
 Introduce a pressure gauge with a full scale of
at least 250 bar in the special quick coupling
(1/4” BSP) D .
 Using the ground control panel lift the
pantograph (lower boom) up to the end stop.
 Check the detected pressure value. The correct
value should be as stated in the “ Technical
Features ".
Fig.27
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) D .
 Locate the pressure relief valve of lifting circuit B .
 Unscrew the dowel of the lock-nut;
 Perform lifting from the control panel on ground. Keep on lifting to stroke-end and force a bit.
 Adjust the pressure relief valve by means of the adjustment dowel to reach the pressure value indicated in
" Technical Features ".;
 Once calibration has been carried out, lock the adjusting dowel by means of the lock-nut.
ATTENTION!
THIS OPERATION IS A CRUCIAL MAINTENANCE TASK AND SHOULD BE STRICTLY CARRIED
OUT BY SPECIALIZED TECHNICIANS.