Duncan Renovator AS4000, Руководство пользователя

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Commisioning Phasing Cylinders
1. General
(a) The cylinders will re-phase in both directions. Each piston is fitted with 2 poppet valves which open at
the end of the stroke to allow oil to bypass the piston. The bypass of oil at the end of the stroke allows for
initial bleeding of the system and re-phasing in operation.
(b) The valve in the piston is a precision device,
CLEANLINESS IS OF THE UTMOST IMPORTANCE.
Contamination in the oil will accelerate deterioration of the valve seat. Cylinders will creep once the
integrity of the seating is lost.
2. Bleeding the System
(a) Initial bleeding after connection to the tractor
Purge all air from the system by fully stroking rams in both directions. Allow the oil to flow through the
cylinders with the tractor at an idle for a minimum of 2 minutes at each end of the stroke.
(b) Re-phasing after initial bleeding
After initial bleeding the cylinders will only require occasional re-phasing during operation. This is done by
extending the rams for about 30 seconds or until all cylinders have reached the end of their stroke.
3. Fault Finding
1. Cylinders creeping during operation
There are two primary causes of this:
(i) Air in the hydraulic system
(ii) By passing of the poppet valve.
(a) Check that there is no air in the system. Raise and lower the machine. All cylinders should move
instantaneously, any lag indicates that there is air in the system. Other signs of air in the system are hoses
vibrating/squealing or the control handle shuddering. Re-bleed the system if necessary.
(b) If there is no sign of air in the system and the cylinders still creep, raise the machine off the depth stop
and measure the movement of each cylinder rod.
(c) If both cylinders move at the same rate it is likely to be the control valve/lock out valve that is leaking.
(d) If the slave continues moving after the master cylinder has hit the depth stop it is likely to be the piston
in the master cylinder that is bypassing.
(e) If the slave cylinder extends while the master cylinder retracts it is likely to the the piston in the master
cylinder that is bypassing.
(f) If the master cylinder does not move but the slave does it is likely to be the piston in the slave cylinder
that is bypassing.
(g) If the piston is bypassing it is likely to be contamination in the phasing valve. The cylinder will have to
be dismantled, cleaned and fitted with a new poppet valve.
‘Renovator AS4000’
Phasing Cylinders