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Fault table
The safety valve is not sensitive to faults as long as the specified application
conditions are complied with, in particular the oil quality and the operating
temperature.
Table 22: Fault table
Fault
The response
pressure indicated
on the component
marking is not
reached during
testing at the test
stand.
The response
pressure indicated
on the component
marking is not
exceeded during
testing at the test
stand.
If the response
pressure is exceeded,
the system pressure
increases excessively
even though
the safety valve
responds.
During bleeding,
the system pressure
exceeds the
10% limit above
the maximum
admissible pressure
(see EC Pressure
Equipment Directive
2014/68/EU,
Appendix I, chap. 7.3).
Safety valve response
pressure is too low.
Possible cause
A valve with unsuitable
response pressure has been
installed.
The safety valve is damaged and
blocked internally.
A safety valve with insufficiently
dimensioned flow was installed.
The T port of the safety valve
is connected via a line with
excessive flow resistance.
The viscosity of the hydraulic
fluid is outside the valve
specification.
A safety valve with unsuitable
response pressure has been
installed.
The difference between
operating pressure and
response pressure of the safety
valve is too small.
RE 25880-B/10.18, DBA...1X/...E, Bosch Rexroth AG
Troubleshooting
Remedy
Check the specified response pressure
of the valve by means of the last figure
of the component marking at the valve
or name plate.
Select and order a valve with suitable
response pressure.
Replace the safety valve.
Select and order a safety valve with
suitable specified flow.
Use larger discharge pipes (increase
outlet diameters), avoid a deflection of
flow, observe the maximum admissible
counter pressure in the discharge
line, see chapter 9.3 "Operation with
counter pressure in the discharge line".
Check whether a suitable hydraulic
fluid can be used in the system and
exchange the hydraulic fluid.
Check the specified response pressure
of the safety valve by means of the last
figure of the component marking at
the safety valve or name plate. Select
and order a safety valve with suitable
response pressure.
Check whether the system can be
operated at lower operating pressure
or select and order a safety valve with
suitable response pressure.
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