5
WILDEN PUMP & ENGINEERING, LLC
WIL-10060-E-03
RIGHT STROKE
LEFT STROKE
RIGHT STROKE
S e c t i o n 3
H O W I T W O R K S — P U M P
The Wilden diaphragm pump is an air-operated, positive displacement, self-priming pump. These drawings show the flow pattern
through the pump upon its initial stroke. It is assumed the pump has no fluid in it prior to its initial stroke.
FIGURE 1 When the solenoid is
energized, the air valve directs pressure
to the back side of diaphragm A . The
compressed air is applied directly to the
liquid column separated by elastomeric
diaphragms . The diaphragm acts as a
membrane between the compressed air
and the liquid, balancing the load and
mechanical stress from the diaphragm .
The compressed air moves the diaphragm
away from the center section of the pump .
The opposite diaphragm is pulled in by
the shaft connected to the pressurized
diaphragm . Diaphragm B is on its
suction stroke; air behind the diaphragm
has been forced out to the atmosphere
through the exhaust port . The movement
of diaphragm B toward the center section
of the pump creates a vacuum within
chamber B . Atmospheric pressure forces
fluid into the inlet manifold forcing the
inlet valve ball off of its seat . Liquid is
free to move past the inlet valve ball and
fill the liquid chamber (see shaded area) .
FIGURE 2 When the solenoid valve is
deenergized, the air valve redirects
pressurized air to the back side of
diaphragm B . The pressurized air forces
diaphragm B away from the center
section while pulling diaphragm A to the
center section . Diaphragm B is now on
its discharge stroke . Diaphragm B forces
the inlet valve ball onto its seat due to the
hydraulic forces developed in the liquid
chamber and manifold of the pump . These
same hydraulic forces lift the discharge
valve ball off of its seat, while the opposite
discharge valve ball is forced onto its seat,
forcing fluid to flow through the pump
discharge . The movement of diaphragm
A toward the center section of the pump
creates a vacuum within liquid chamber
A . Atmospheric pressure forces fluid into
the inlet manifold of the pump . The inlet
valve ball is forced off of its seat allowing
the fluid being pumped to fill the liquid
chamber .
FIGURE 3 Once the solenoid valve is
reenergized the air is directed to the
back side of diaphragm A, which starts
diaphragm B on its exhaust stroke . As
the pump reaches its original starting
point, each diaphragm has gone through
one intake and one discharge stroke .
This constitutes one complete pumping
cycle . The pump may take several cycles
to completely prime depending on the
conditions of the application .
