8.
Trouble Shooting
Power supply
of pilot valve
Phenomenon
Cause
Countermeasure
OFF
Air leaks from 3 (R) port.
1. Inclusion of foreign matter onto sheet
surface of the valve assembly.
2. Damage on rubber portion of the valve
assembly.
3. Damage of the valve spring.
4. Inclusion of foreign matter onto sheet
surface of the piston assembly.
5. Damage on rubber portion of the
piston assembly.
6. Damage of the piston spring.
1. Please air blow the sheet surface
of the valve assembly.
2. Please replace the valve assembly.
3. Please replace the valve spring.
4. Please air blow the sheet surface
of the piston valve assembly.
5. Please replace the piston valve
assembly.
6. Please replace the piston spring.
The residual pressure is not
exhausted.
1. Manual override position of the pilot
valve assembly is ON.
2. Failure of the pilot valve assembly.
3. Damage of the spool spring.
1. Please switch the manual override
OFF.
2. Please replace the pilot valve
assembly.
3. Please replace the control valve
assembly.
ON
Air is not supplied to 2 (A)
port.
(There is no leakage from
3 (R) port.)
1. Decrease of the operation pressure.
2. Failure of the pilot valve assembly.
3. Condition of the needle operation is
closed.
1. Please supply the operating
pressure within 0.2 to 1.0MPa.
2. Please replace the pilot valve
assembly.
3. Please turn the needle to the
open direction (“+” direction).
Air is not supplied to 2 (A)
port.
(There is a leakage from
3 (R) port.)
1. Decrease of the operation pressure.
2. Air supply capacity from 1 (P) port
is not sufficiency.
(Combined sonic conductance is
too small)
1. Please supply the operating
pressure within 0.2 to 1.0MPa.
2. Please refer to the precaution
of “PIPING”, and review the
piping and the equipment on
the upstream side.
Air leaks from 3 (R) port.
(small amount of leakage)
1. Inclusion of foreign matter onto sheet
surface of the control valve assembly.
2. Damage on rubber portion of the
control valve assembly.
3. Inclusion of foreign matter onto sheet
surface of the valve assembly.
4. Damage on rubber portion of the
valve assembly.
1. Please air blow the sheet surface
of the control valve assembly.
2. Please replace the control valve
assembly.
3. Please air blow the sheet surface
of the valve assembly.
4. Please replace the valve assembly.
Flow adjustment by the
switching operation of the
needle (open/close) cannot
be done.
(Air leaks from 2 (A) port
even if the needle is closed.)
1. Inclusion of foreign matter onto sheet
surface of the control valve assembly.
2. Damage on rubber portion of the
control valve assembly.
1. Please air blow the sheet surface
of the control valve assembly.
2. Please replace the control valve
assembly.
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