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3) Replacing non-return valves (simultaneous replacement of diaphragms and non-return
valves is recommended)
Use tools No.1, 2, 3, 5, 7, 8, 9, and 10.
(1) Remove up to the pump head C in accordance with steps (1)~(8) for replacement of
the diaphragm.
(2) Remove the type-B inlet pipe from the non-return valve.
(3) Remove the valve seat retainer from the non-return valve casing, and remove the
valve seat and non-return valve.
(4) After disassembly, clean the various components with a paper towel soaked in ethyl
alcohol.
(5) Clean the new non-return valve with a paper towel soaked in ethyl alcohol, and place
in the non-return valve casing.
(6) Turn the side of the valve seat with the depression downwards.
Note: Tap the valve seat gently and check that it is fully in place.
(7) Apply a small amount of Loctite
®
242 to the valve seat retainer, and turn with a slotted
screwdriver.
(8) Apply a uniformly thin covering of vacuum grease to the O-ring in the type-B inlet pipe.
(9) Screw the type-B inlet pipe into the non-return valve casing.
Note: Take care not to cut the O-ring when screwing in the inlet pipe.
Type-B inlet
pipe
Non-return valve
casing
Pump head 1-1
Valve seat retainer
Non-return valve
Valve seat
Non-return valve replacement diagram (photo shows valve for DAU-120)
