WIL-11113-E-04
6
HS430S High Pressure Bolted Metal
SECTION 3
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.
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 each stroke.
FIGURE 1
When air pressure is supplied to the
pump, the air valve directs pressure to the back
side of diaphragm A. 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 towards 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
Once the shaft has reached the
end of its stroke, the air valve redirects
pressurized air to the back side of diaphragm B.
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 condition of the
application.
HOW IT WORKS – AIR-OPERATED DOUBLE-DIAPHRAGM PUMP
HOW IT WORKS – AIR DISTRIBUTION SYSTEM
