WIL-10440-E-03
Wilden
®
6
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.
CLOSED
OUTLET
OPEN
OPEN
OUTLET
CLOSED
CLOSED
OUTLET
OPEN
B
A
B
A
B
A
CLOSED
CLOSED
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; a balanced load
removes 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
diaphragm, 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. Atmospheric 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.
HOW IT WORKS
— AIR DISTRIBUTION SYSTEM
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
Section 3
HOW IT WORKS
— PUMP
