5
Functional description
5.1 Drive unit
The metering pump is an oscillating diaphragm pump, the stroke length of
which can be adjusted. An electric motor drives the pump.
5.2 Liquid End
The heart of the liquid end is a highly resistant piston (4) made from
coated stainless steel. The suction valve (1) closes as soon as the piston
(4) is moved in to the dosing head and the feed chemical flows through the
discharge valve (3) out of the dosing head. As soon as the piston moves in
the opposite direction, the discharge valve (3) closes due to the negative
pressure in the dosing head and fresh feed chemical flows through the
suction valve (1) into the dosing head.
Use the flushing collar (6) to flush the sealing surface of the piston.
P_SI_0144_SW
3
2
7
4
6
5
1
Fig. 7: Cross-section through the liquid end
1
Suction valve
2
Dosing head
3
Discharge valve
4
Piston
5
Packing collar
6
Flushing collar
7
Flushing connector
Functional description
14
Summary of Contents for Sigma / 2 Basic Type SBKa
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