Specifications

WIL-10410-E-02 3 WILDEN PUMP & ENGINEERING, LLC
Section 3
how it works—pump
The Wilden diaphragm pump is an air-operated, positive displacement, self-priming pump. These drawings show 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 The air valve directs pressurized
air 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 separation membrane between the
compressed air and liquid, balancing the
load and removing mechanical stress
from the diaphragm. The compressed
air moves the diaphragm away from
the center 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 atmosphere through the exhaust
port of the pump. The movement of
diaphragm B toward the center of the
pump creates a vacuum within chamber B.
Atmospheric pressure forces fluid into
the inlet manifold forcing the inlet valve
ball off its seat. Liquid is free to move
past the inlet valve ball and fill the liquid
chamber (see shaded area).
FIGURE 2 When the pressurized dia-
phragm , diaphragm A, reaches the limit
of its discharge stroke, the air valve
redirects pressurized air to the back side of
diaphragm B. The pressurized air forces
diaphragm B away from the center
while pulling diaphragm A to the center.
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 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 of the pump creates a
vacuum within liquid chamber A. Atmos-
pheric pressure forces fluid into the inlet
manifold of the pump. The inlet valve ball
is forced off its seat allowing the fluid
being pumped to fill the liquid chamber.
FIGURE 3 At completion of the stroke,
the air valve again redirects air 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 exhaust 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.
The heart of the patented Pro-Flo
®
SHIFT Air Distribution
System (ADS) is the air valve assembly. The air valve design
incorporates an unbalanced spool with the small end of the
spool being pressurized continuously while the large end of
the spool is alternately pressurized, then exhausted to move
the spool. The air valve spool directs pressurized air to one
chamber while exhausting the other. The air forces the main
shaft/diaphragm assembly to move to one side – discharging
liquid on that side and pulling liquid in on the other side. When
the shaft reaches the end of the stroke, the inner piston actuates
the pilot spool, which controls the air to the large end of the air
valve spool. The repositioning of the air valve spool routes the
air to the other air chamber. The air control spool allows air to
flow freely into the air chamber for the majority of each pump
stroke, but it significantly restricts the flow of air into the air
chamber when activated by the inner piston near the end of the
each stroke.
OUTLET
CLOSED
CLOSEDOPEN
OPEN
INLET
B A
OUTLET
CLOSED
CLOSED OPEN
OPEN
INLET
B A
OUTLET
CLOSED
CLOSED OPEN
OPEN
INLET
B A
how it works—air distribution system