24
6 Maintenance
BÜCHI
Vac
V-500/V-501/V-502/V-503
Removal and cleaning of valve head
1. Release both of the black hose couplings GL-14 between
the pump heads.
2. Using the allen wrench provided, loosen crosswise with a
quarter-turn each and remove the 4 screws on the valve
head top.
3. Carefully remove the valve head top with the valve head
and glass head.
4. Place the entire part on a soft surface. The glass head
can now be removed by applying light pressure to the
valve head.
The valve head, glass head, and diaphragms can now be
cleaned with a suitable cleansing agent (e.g., acetone), or
defective parts can be replaced. The valves of the valve head
can be cleaned by putting the whole valve head into an acetone
bath. If they are still contaminated, use an ultrasonic bath.
Avoid hitting the sides and edges of the glass head. A glass
head which has been dropped may not suffer any apparent
damage, but could break if used again!
Removal of the diaphragms
Only remove the diaphragms if they are broken or can not be
cleaned in a mounted way. They can be released by turning
them counterclockwise.
Replacement of the diaphragms
Before you replace the diaphragm make sure, that the
diaphragm holder fits tight on the lower side of the diaphragm.
There must be
no gap
between holder and diaphragm
The diaphragm and the diaphragm holder can then carefully
be screwed on and tightened by hand with the same force as
your have needed to detache it before! Check again if there is
no gap
between diaphragm and holder after replacing the
diaphragm.
