WIL-10272-E-01
Wilden
®
19
Disassembly / Reassembly
Air Valve / Center Section Disassembly
The air valve assembly consists of both the air valve body and piston
and the center block. The unique design of the air valve relies only on
differential pressure to effect the diaphragm shift. It is reliable and
simple to maintain. The bushing in the center block, along with the
diaphragm shaft, provides the “trigger” to tell the air valve to shift. The
following procedure will ensure that the air valve on your Wilden pump
will provide long trouble-free service.
AIR VALVE BODY AND PISTON ASSEMBLY AND DISASSEMBLY
The air valve can be disconnected from the pump by removing the four
socket head cap screws which attach it to the center block. The piston
should move freely and the ports in the piston should line up with the
ports on the face of the air valve body (see
Figure D).
The piston
should also appear to be dull, dark gray in color. If the piston appears
to be a shiny aluminum color, the air valve is probably worn beyond
working tolerances and should be replaced.
If the piston does not move freely in the air valve, the entire air valve
should be immersed in a cleaning solution.
NOTE:
Do not force the piston by inserting a
metal object.
This soaking should remove any accumulation of sludge and grit
which is preventing the air valve piston from moving freely. Also,
remove and clean the air valve screen.
If the air valve piston does not move freely after the above cleaning,
the air valve should be disassembled as follows: Remove the snap
ring from the top end of the air valve cylinder and apply an air jet to
the 3/16-inch hole on the opposite end of the air valve face
(see
Figure C).
CAUTION:
The air valve end cap may come out with
considerable force. Inspect the piston and cylinder bore
for nicks and scoring
.
Figure A
AIR FILTER
SCREEN
CENTER BLOCK AIR VALVE BODY
AIR VALVE ASSEMBLY
AIR INLET
AIR VALVE
PISTON
CENTER BLOCK
BUSHING
END CAP
Figure B
Figure C
Figure D
