VWR VP 8 Vac Manuel D'instructions page 14

English
Health hazard due to dangerous substances
in the pump!
Depending on the substance transferred, caustic burns or poisoning are possible.
 Wear protective clothing if necessary, e.g. protective gloves.
WARNING
 Flush pump before replacing the diaphragm and valve plates/sealings (see chapter 8.2.1).
Removing pump head
1. On the pneumatic head connection (3), loosen the union nuts (2) by
hand. Then slightly loosen the angle-fitting (1) in the pump head (4)
by turning it anticlockwise, so that the connecting tube can be pulled
out.
2. On both pump heads mark the position of top plate (fig. 10/5), head
plate (fig. 10/6), intermediate plate (fig. 11/8) and adapter relatively
to each other by a drawing line with a felt-tip pen. This helps to avoid
incorrect assembly later.
3. Loosen the outer screws (5) on the pump head/pump heads.
4. Carefully remove pump heads.
Change diaphragm
Replace the diaphragms of pump heads consecutively in order to
ensure that the same number of diaphragm spacers is used as
before
1. Push down one diaphragm until other diaphragm is pushed upwards
to its highest position.
2. Carefully unscrew the upper diaphragm (1) anti-clockwise using both
hands.
3. Replace spacer thick (2) and spacers thin (3) onto the screw thread
of the new diaphragm (same number and order).
4. Screw in the new diaphragm and tighten it by hand.
5. Carry out steps 1 to 4 for the second pump head.
Change valve plates/sealings
Replacing the valve plates/sealings of both pump heads
consecutively.
1. At one pump head: Loosen screw (1) in the center of the top plate
(2).
2. Remove top plate (2) and head plate (3) from intermediate plate (5).
Valve plates/sealings (4) are visible.
3. Remove old valve plate/sealings (4).
4. Clean intermediate plate (5) carefully (if there should be deposits in
the recesses in the intermediate plate).
5. Insert new valve plates/sealings (4) in the recesses in the
intermediate plate (5).
6. Carry out steps 1 to 5 for the second pump head.
7. Dispose of the old diaphragms and valve plates/sealings properly.
Refitting pump head
1. At one pump head: Apply pressure all around the edge of the
diaphragm.
2. Place the intermediate plate (8) with valve plates/sealings on the
adapter in accordance with the felt-tip pen marking.
3. Place the head plate (6) on the intermediate plate (8) in the position
indicated by the guide pin (7).
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Fig. 7: Removing pump head
Fig. 8: Changing diaphragm
Fig. 9: Changing valve plates/
sealings