Gardner Denver RFL Series, Owner'S Manual

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RFL-7-500 Page 28
8.2.6 Non-Return Valve
No maintenance is necessary for the non-return valve. We recommend a first inspection after 300 hours of operation.
Inspect the valve for oil carbon deposits and determine the interval for the next inspection on the basis of the valve condition. The
thickness of the oil carbon layer must not exceed 1mm.
Fig. 8.2 Non-return valve
1. Machine body 2. Guide plate
3. Valve plate 4. Cylinder pin
5. Two Belleville washers
Sealing and gliding surfaces must be free of oil carbon deposits in order to guarantee proper functioning of the non-return valve.
Should cleaning be necessary, the valve must be removed.
•
Insert a slide hammer into the M6 tapped end of the cylinder pin (4) and carefully remove the guide plate (2), valve seat (3)
and pin from the body.
•
After careful cleaning, check the valve seat for the quality of seal. If the seal leaks, regrind it with grinding paste.
•
Before reassembling the valve, which is carried out in reverse order, the sliding surfaces of the cylinder pin (4) should be
coated with MOLYKOTE oil, type M 55 (manufactured by Dow Corning).
8.2.7 Ventilation Valve
If the ventilation valve is mounted in a dirty position, the pressure compensation bore can gradually close with dirt which would
restrict the function of the valve.
To avoid this, make a visual inspection of the ventilation valve at regular intervals (at least every 3 months or more frequently if the
ventilation valve is covered with dirt). Clean if necessary.