21
BÜCHI
Vac
V-511/512/513
6 Maintenance
5. Now connect the connecting hose, tighten the hose con-
nections, and then assemble the second pump head the
same way as the first one.
6. If the vacuum is not achieved, it may be necessary to
replace or clean the valve head seals. To do this, remove
the valve heads as indicated in 6.2. 1-4.
Carefully take the white sealing rings out of the retainer using
the valve reed and place them in an ultrasonic bath (if possible).
Refit the cleaned individual parts or replacement parts as
shown in the diagram.
6.3
Function control
A functional control should be carried out at least once a year
as follows:
Pump:
The suction time for a dry volume of 3 litres at 20 mbar should
not take longer than 60 seconds.
The functional control should also include a regular inspection
of hoses for any brittle areas and leaks.
If the pump does not perform to specification, the pump,
diaphragms and valve heads must be cleaned and replaced,
if necessary.
