Maintenance
Clean suction and pressure valves
34
© Lutz-Jesco GmbH 2018
BA-10407-02-V08
Motor-driven diaphragm dosing pump
MEMDOS LB
Operating instructions
12.5 Clean suction and pressure valves
Contaminated valves affect the dosing preceision and this means that
you should clean the valves on a regular basis.
i
Suction and pressure valves differ in the sequence of assem-
bly of the individual parts. Disassemble them one at a time to
prevent parts being mixed up.
Finally, screw the valves at first finger-tight into the dosing head. While
doing this, ensure that the seals or O-rings are correctly seated inside the
valves and the dosing head.
WARNING
Caustic burns or other burns through dosing media!
If valves are serviced without replacing the seals, it can lead to leak-
age and to an eventual escape of the dosing media.
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Replace the seals when maintaining the valves.
Required torque for tightening plastic valves into the dosing head:
MEMDOS LB
Torque
(
±
10%)
4 - 20
3 Nm
4-HP - 20-HP
3 Nm
35 - 60
5 Nm
80 - 260
15 Nm
310 - 400
15 Nm
510 - 1010
20 Nm
Table 29: Valve torque
For stainless steel valves with fibre seals or seals made of PTFE, the given
torque values are the minimum values. Due to their elastic deformation,
these must be re-tightened several times.
