Planmeca Compact I, Technical Manual

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Chapter G - PARTS REPLACEMENT & REPAIR
Planmeca Compact i G-15
SUCTION SYSTEM RELATED
Technical Manual
Pulse valve opens (after every five seconds)
Electrical function:
Control voltage is connected to the microvac, pulse and
flushing valves.
Pneumatical function:
The vacuum is connected to the membrane assembly
(drain and intermediate membranes). The intermediate
membrane is forced to shrink by the vacuum. The pres-
sure balancing membrane stays in position (due to the
pressure difference between the chambers) preventing
water from flowing to the lower chamber. The drain mem-
brane blocks the opening from the lower chamber to the
drain. The vacuum also closes the breather valve.
After about 0.5 seconds the pressure difference between
the chambers is balanced by the pressure balancing tube.
The pressure balancing membrane moves downwards
due to gravity allowing saliva and water to flow to the lower
chamber.
Pulse valve
Membrane
assembly
Drain membrane
Breather
valve
Pressure
balancing tube
Intermediate
membrane