Service
Manual PageEdition
Type
31
8911
34. Inlet Valve, Water
Data
Capacity at 300 kPa 300 litres/min
Operating limits 40-1000 kPa

Description

The valve is electromagnetically operated and has
a rubber diaphragm as its opening and closing
element. The valve utilises the water pressure
when opening and closing.
When the electromagnetic is de-energised, the
valve is closed.
The water pressure acts through the pilot pressure
opening on the top of the rubber diaphragm.
Because the water pressure is acting on a relatively
larger area on the top of the diaphragm than on the
bottom (part of the underside of the daphragm is in
contact with the outlet of the valve, where there is
no prssure) the water pressure from below is
insufficient to lift the diaphragm, so that the
diaphragm forms a seal against the valve seat.
When the magnet is energised, the opening from
the top of the diaphragm to the outlet of the valve is
opened. Since the diameter of this opening is
greater than that of the pilot opening, the diameter
of which is limited by the balancing nozzle, the
pressure on the top of the diaphragm falls. The
water pressure on the bottom of the diapragm can
then lift the diaphragm and open the valve. 1364
Coil Armature
Compres-
sion
spring
Diaphragm
Balancing
nozzle
Inlet Valve body
Outlet
1365
Coil
Armature
Duct to valve outlet
Pilot pressure duct
Balancing
nozzle
Rubber diaphragm Compression Spring
34