Trouble Shooting - SMC Networks VGA342R Series Operation Manual

Trouble shooting

Perform troubleshooting with higher possibility based on the failure phenomenon.
Operation failure
Sealing failure
Problem
The pilot valve does not switch.
Pilot valve switches. Main valve does
not switch. Or, switching is delayed.
Air leakage from the main valve air
exhaust [3(R) port*]
*For body ported type and N.O.
specification, from 1(P) port.
Air leakage from the gasket
Air leakage from the pilot valve air
exhaust port (PE port).
- 8 -
Possible causes
Pilot pressure decreased.
Foreign matter is caught in the pilot valve or spool valve.
External pilot pressure decreased.
O-ring is swollen.
Excessive lubrication
O-ring is worn.
Lodging of foreign matter.
Incomplete switch of spool valve
Sealing failure of actuators (such as cylinder)
Insufficient tightening of the bolt
O-ring is swollen.
Foreign matter caught in the seat
Countermeasures
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VG300**-OMH0006-A