10.3 Valve repair
Unsuitable spare parts for the valves may lead to
problems for the pumps.
–
Only use new components that are especially
adapted to fit your valve (both in terms of
shape and chemical resistance).
–
Use the correct spare parts kits. In the event of
doubt, refer to the exploded views and ordering
information in the appendix.
Clean the discharge and suction valves only one
after another as they cannot be differentiated using
the arrow markings.
10.3.1 Double ball valves
Taking the discharge valve apart
1.
Unscrew the discharge valve from the dosing head and rinse
out.
2.
Dismantle the discharge valve.
3.
Rinse and clean all parts.
4.
Replace the worn parts and seals.
Assembling the discharge valve
When assembling, take note of the orientation of
the valve seats (3). The valve seats (3) are used
as a ball seat on the fine machined side and as a
ball cage and spring guide on the other side. The
fine machined side must point in the flow direction
with all valve seats.
When assembling the valves, take note of the
sequence:
Teflon – metal – Teflon – metal - ...
1.
Slide into the valve body (1) one after another:
n
one seal (2) and one valve seat (3) - direction!
n
one seal (2) and one valve bushing (4)
n
(If fitted: one spring (*) into the spring guide of the valve
seat (3))
n
one ball (5) into the valve body (1)
n
one seal (2) and the second valve seat (3) - direction!
n
one seal (2) and the second valve bushing (4)
n
(If fitted: the second spring (*) into the spring guide of the
valve seat (3))
n
the second ball (5) into the valve body (1)
n
one seal (2), the third valve seat (3) - (direction!) and a
further seal (2)
Cleaning a discharge valve
1
*
*
7
6
5
4
3
2
Fig. 22: Discharge valve (double ball
valve)
Repairs
64
