Latest Update: 20/04/2018
3
PROBLEM HANDLING: CAUSES AND SOLUTIONS
PROBLEMS
PROBABLE CAUSES
SOLUTIONS
Valve recycles frequently
Check Valve O-ring worn out
Leaking couplings
Bypass blocked or throttled
Replace
Check and Restore
Clean or Adjust
Valve does not reach
desired pressure level
Piston seals worn out
Material matter between seat and shutter
Nozzle worn out
Replace
Clean up seat
Replace
Pressure spikes
Less than 5% of total flow rate discharged in bypass
Excessive flow rate in bypass
Adjustment carried out with spring completely
compressed
Reset
Choose different valve type or adjust passages
Loosen knob and replace nozzle
Valve does not bypass at
low pressure
Jammed check valve
Check valve O-ring worn out
Material matter on check valve
Clean or replace
Replace
Clean
REGULATIONS :
See Standard Manual.
referred to in the
Declaration of Conformity
.
For a correct use, follow the instructions given in this booklet and re-print them on the Use and
Maintenace Manual of the machine.
Make sure that you are given
the original Declaration of Conformity
for the chosen item. This booklet is
applicable for all unloader valves type VB 450-200/300
MAINTENANCE
All maintenace operations must be carried out by qualified personnel only.
ROUTINE:
every
400 hours of operation (around 10000 cycles), check and lubrify seals with waterproof grease.
EXTRAORDINARY:every
800 hours of operation (around 20000 cycles), check conditions of seals and other internal
components. If required, replace them with original PA spare parts.When installing the spares, lubrify them with
waterproof grease.
IMPORTANT
: in case of replacement, assemble the valve correctly, resetting all conditions to starting levels
and making sure to fix the nut pos.25 with thread locking liquid.
The manufacturer is not liable for damages resulted from incorrect fitting and maintenance.
Technical data, descriptions and illustrations are indicative and subject to modification without notice.
