Solenoid diaphragm pump
Series R/RS 204.1
Operating Instructions
20
www.sera-web.com
Subject to technical modifications!
TA 416
Rev.
11 en
04/2013
7.2.5
Suction / pressure valve
The pump valves are always ball valves which can only func-
tion properly when they are installed in a vertical position. The
condition of the valves is decisive for the operational behaviour
of the pump. The valves should only be exchanged completely.
Pay attention to the flow direction when installing the valves
(see Fig. 13).
CAUTION !
Pressure valve above, suction valve below!
Flow
direction
Fig. 13 Double valves, for evample. PVDF-FRP
7.2.6
Automatic ventilation device (RS-
design)
The self-venting controlled magnetic diaphragm pumps of the
series RS 204.1 are equipped with a vent valve which is in-
stalled on the pump pressure nozzle and which cannot be ret-
rofitted.
The pump vents the dosing head of the pump and the suction
line, either externally or manually controlled or automatically at
a predefined interval.
The vent valve consists of a combination of a check valve,
which should prevent a back-flow of the medium, and a sole-
noid valve (see Fig. 14). When the controlled solenoid valve
opens the spring-loaded rotor with attached seal is lifted from
the valve seat and pressure is relieved from the space be-
tween the pump valve and the integrated check valve.
Thus pump and the pipes on the suction side can be vented
without pressure.
Please note that the required stroke volume is covered by the
usable stroke length range.
CAUTION !
Always install the pump above the suction tank and lay
the return pipe with descending gradient to the suction
tank!
Vent valve
Solenoid valve
Check
valve
Hose
nozzle
Return line
Fig. 14 Vent valve, controllable
