BA-
45.01.0 • US •01/15
7-3
7. Maintenance
7.2.6
Non-return valve
No maintenance of the non-return valve is necessary.
We recommend an initial check after 300 hours of
operation.
The valve must be checked for oil carbon deposit, and
depending on its condition, the interval for the next
check must be fixed. The layer of oil carbon must not
exceed 1 mm in thickness.
Sealing and sliding surfaces must be free
from oil carbon deposits so that the function
of the non-return valve is preserved.
1.
Valve housing
2.
Guide plate
3.
Valve plate
4.
Cylinder pin
Figure 7-2:
Non-return valve
If cleaning should be necessary, the valve must first be
removed.
Remove the mounting screws, and pull out the non-
return valve between the mounting flanges.
To dismantle the valve, press down the valve plate
(7.3/3) until it touches the guide plate (7.3/2), then
remove the latter carefully from the valve housing
centre (7.3/1) with a press.
After thorough cleaning, check the valve seating for
the quality of the seal. If there is a leak, grind the
valve seating afresh with grinding paste.
Before assembly, which is carried out in reverse
order, the sliding surfaces of the cylinder pin (4)
should be coated with MOLYKOTE oil, type M 55
(manufacturer: DOW CORNING).
7.2.7
Ventilation valve
If incorrectly installed the vent hole C, used for
pressure compensation of the ventilation valve may
block and reduce the function of the ventilation valve.
Figure 7-3:
Ventilation valve
To avoid this carry out a visual check of the ventilation
valve regularly (at least every 3 months and, if
necessary, dismantle the ventilation valve, clean the
dirt and blow out the bore hole for pressure
compensation with compressed air.
Proceed as follows for dismantling:
Unscrew fixing screws (7.4/A).
Remove upper valve part (7.4/B) and clean valve
interior.
Blow out the vent hole for pressure compensation
(7.4/C) with compressed air from the inside to the
outside.
Reassemble in reverse order.
Watch for correct centering of the pressure
spring (7.4/D) and correct seat of the
rolling diaphragm (7.4/E) during assembly.