ALMAC BiBi 850-BL, Use And Maintenance Manual

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BIBI 850-BL Use and maintenance manual Rev.00
82
6.8 Inspection of lift circuit pressure relief valve operation
Check track tension at the inspection frequency indicated in the general chart. This valve acts as a
supplementary protection device for the electronic overload device and prevents the platform from
lifting once the nominal load has been exceeded by 50%.
To perform the test, unscrew the inlet plug “
M1
” on the hydraulic valve unit ( see
drawing above ) and fit on a 1/4” Gas pressure gauge union as shown in the figure
alongside.
Now screw a tube for the pressure gauge fitting and a pressure gauge with 250 bar
full scale into the union described above.
While one operator remains on the ground so as to check the pressure relief valve
setting, another operator must work from the console in order to:
a) start the platform and combustion engine
b) press the platform "descent" button ( 16 ) until it reaches the limit and hold it down. This
activates the pressure relief valve of the lift circuit.
c) Read the pressure on the gauge, which should be 190 bar ± 5 bar
The valve is calibrated during the testing operations performed by ALMAC S.r.l. and should not
require further adjustment unless:
 the hydraulic circuit is replaced
 the actual pressure relief valve is replaced.
Pressure
gauge socket
-M2-
Lift circuit pressure
relief valve