SANDPIPER M20 Non-Metallic - Manual (Page 25)

m20nmdl3sm-rev0713 Model M20 Non-Metallic Page 23
DIAPHRAGM SERVICING
To service the diaphragms first
shut off the suction, then shut off the
discharge lines to the pump. Shut
off the compressed air supply, bleed
the pressure from the pump, and
disconnect the air supply line from the
pump. Drain any remaining liquid from
the pump.
Step #1: See the pump composite
repair parts drawing, and the diaphragm
servicing illustration.
Using a wrench or socket, remove
the 16 capscrews (items 8), hex nuts
and washers that fasten the elbows
(items 19 & 20) to the outer chambers
(items 16). Remove the elbows with the
manifolds and spacers attached.
Step #2: Removing the outer
chambers.
Using a wrench or socket, remove
the 16 capscrews (items 9 & 11), hex
nuts and washers that fasten the outer
chambers, diaphragms, and inner
chambers (items 15) together.
Step #3: Removing the diaphragm
assemblies.
Use a 1½" (38mm) wrench or
six pointed socket to remove the
diaphragm assemblies (outer plate,
diaphragm, and inner plate) from the
diaphragm rod (item 34) by turning
counterclockwise.
Inspect the diaphragm (item 17)
for cuts, punctures, abrasive wear
or chemical attack. Replace the
diaphragms if necessary.
Step #4: Installing the diaphragms.
Push the threaded stud of the outer
diaphragm plate through the center
hole of the diaphragm. Thread the inner
plate clockwise onto the stud. Use a
torque wrench to tighten the diaphragm
assembly together to 480 in Lbs. (54.23
Newton meters). Allow a minimum of
15 minutes to elapse after torquing,
then re-torque the assembly to
compensate for stress relaxation in
the clamped assembly.
Step #5: Installing the diaphragm
assemblies to the pump.
Make sure the bumper (item 5) is
installed over the diaphragm rod.
Thread the stud of one diaphragm
assembly clockwise into the tapped
hole at the end of the diaphragm rod
(item 34) until the inner diaphragm plate
is flush to the end of the rod. Insert rod
into pump.
Fasten the remaining outer chamber
(item 17) to the pump, using the
capscrews (items 11 & 12), hex nuts
and flat washers and tighten.
Make sure the bumper (item 6) is
installed over the diaphragm rod.
Thread the stud of the other
diaphragm assembly clockwise into the
tapped hole at the end of the diaphragm
rod (item 34) make sure the 2nd
diaphragm assembly is tight enough
that the inner plate is flush to the end
of the rod. The bead of the end of the
diaphragm should fit into the groove of
the inner chamber.
Fasten the remaining outer chamber
(item 16) to the pump, using the
capscrews (items 9 & 11), hex nuts and
flat washers.
Step #6: Re-install the elbow/
spacer/manifold assemblies to the
pump, using the capscrews (items 8),
hex nuts and flat washers.( Ref.pg 12)
The pump is now ready to be
re-installed, connected and returned
to operation.
OVERLAY DIAPHRAGM SERVICING
The PTFE overlay diaphragm
(item 18) is designed to fit over the
exterior of the standard diaphragm
(item 17).
Follow the same procedures
described for the standard diaphragm
for removal and installation.
Read these instructions
completely, before
installation and start-up.
It is the responsibility of
the purchaser to retain
this manual for reference. Failure to
comply with the recommendations stated
in this manual will damage the pump, and
void factory warranty.
IMPORTANT
One-Piece Bonded DIAPHRAGM
SERVICING (Bonded PTFE with
integral plate)
The one-piece bonded diaphragm
(item 17) has a threaded stud installed
in the integral plate at the factory. The
inner diaphragm plate has a through
hole instead of a threaded hole.
Place the inner plate over the
diaphragm stud and thread the first
diaphragm/inner plate onto the dia-
phragm rod only until the inner plate
contacts the rod. Do not tighten. A small
amount of grease may be applied between
the inner plate and the diaphragm to
facilitate assembly.
I n s e r t t h e d i a p h r a g m / r o d
assembly into the pump and install the
outer chamber. Turn the pump over
and thread the second diaphragm /
inner plate onto the diaphragm rod.
Turn the diaphragm until the inner
plate contacts the rod and hand tighten
the assembly. Continue tightening
until the bolt holes align with the inner
chamber holes. DO NOT LEAVE THE
ASSEMBLY LOOSE.