
The Wilden diaphragm pump is an air-operated, positive displacement, self-priming pump. These drawings show fl ow pattern
through the pump upon its initial stroke. It is assumed the pump has no fl uid 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 fl uid into
the inlet manifold forcing the inlet check
valve off its seat. Liquid is free to move
past the inlet check valve and fi ll 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 check valve 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
check valve off its seat, while the opposite
discharge check valve is forced onto its
seat, forcing fl uid to fl ow 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 fl uid into the inlet
manifold of the pump. The inlet check valve
is forced off its seat allowing the fl uid being
pumped to fi ll 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 suction stroke. As
the pump reaches its original starting
point, each diaphragm has gone through
one suction 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.
NOTE:
The fl uid inlet of the Brahma
Advanced™ pump is located at the top
and the fl uid discharge is located at the
bottom of the pump.
S e c t i o n 3
H O W I T W O R K S — P U M P
WIL-11140-E-03
3
WILDEN PUMP & ENGINEERING, LLC
H O W I T W O R K S — A I R D I S T R I B U T I O N S Y S T E M
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The Turbo-Flo™ air distribution system incorporates one moving
part and consists of an air valve body, air valve piston and center
block. The unique design of the air valve relies on differential
pressure and works in conjunction with the center block bushing
and the shaft/diaphragm assembly to direct pressurized air into
one of the air chambers while exhausting the other. The air causes
the shaft/diaphragm assembly to shift to one side – discharging
liquid on that side and pulling liquid in on the other side. When
the shaft/diaphragm assembly reaches the end of its stroke, the
slots on the shaft align with the slots in the center block bushing
“triggering” the air valve piston to shift in the air valve body. The
repositioning of the air valve piston routes the pressurized air to
the other air chamber.