SANDPIPER MP07D - Manual (Page 4)

Model MP07D Design Level 3 Type 4 Page 4 520-134-000 3/03
which secures the diaphragm and plate to the rod by keeping the diaphragm
engaged with the inner diaphragm chamber by inserting two or three capscrews
through the bolt holes so that the diaphragm cannot rotate when loosening. The
diaphragm plates, diaphragm and bumper will now come off the assembly. Repeat
all actions if the other diaphragm needs to be inspected or replaced.
Procedures for reassembling the diaphragms are the reverse of the above. The
diaphragms must be installed with their natural bulge to the outside, toward the
outer diaphragm plate. Install the inner plate with the flat face against the
diaphragm.
After all components are in position in a vise and hand tight, tighten with a
wrench to approximately 40 ft. lbs. (5.53 kilograms/meters) torque. After both
diaphragm assemblies have been assembled, thread one assembly into the shaft
(hold the shaft near the middle in a vise with soft jaws, to protect the finish). Install
this subassembly into the pump and secure by placing the outer chamber on the
end with the diaphragm. This holds the assembly in place while the opposite side is
installed. Torque the last diaphragm assembly to 30 ft. lbs. (4.147 kilograms/meters).
This final torquing will lock the diaphragm assemblies together. Place the remaining
outer chamber on the open end and loosely tighten the bolts. Replace the manifold
assemblies to square the flanges before final tightening of the remaining bolts,
alternating for progressive tightening, the eight capscrews that secure outer
chamber to inner chamber.
Make sure the o-ring between the Teflon driver chamber and Teflon driver
diaphragm is in place before final torquing of the eight capscrews that hold the
chambers together.
MAINTENANCE AFTER USE
When the pump is used for materials that tend to settle out or transform from
liquid to solid form, care must be taken after each use or during idle time to remove
them and flush the pump as required to prevent damage.
In freezing temperatures the pump must be completely drained when idle. This
model must be tilted to allow the liquid from the chambers to run out of the discharge
port.
MAINTENANCE NOTE
A preventative maintenance procedure should be established to check the
Teflon diaphragms for breakage. Even though this part was proven to be good for
millions of cycles, each application may present its own problems.
The choice of the Teflon unit would tend to show that the material being handled
would not be compatible with the standard Neoprene or other rubber. If a Teflon
diaphragm were to break, the unit would continue pumping via the driver diaphragm.
In a standard Marathon pump, a ruptured diaphragm would show up as air bubbles
in media being pumped or pumped material being blown out the exhaust muffler.
These events would not occur in the Teflon unit until the material in the driver
diaphragm had been attacked and destroyed. If it were to reach that point, the pump
as a whole would stand a chance of being lost instead of just a diaphragm.
SERVICE INSTRUCTIONS:TROUBLE SHOOTING
1. Pump will not cycle
A. Check to make sure the unit has enough pressure to operate and that the air inlet
valve is open.
B. Check the discharge line to insure that the discharge line is neither closed nor
blocked.
C. If the spool in the air distribution valve is not shifting, check the main spool. It must
slide freely.
D. Excessive air leakage in the pump can prevent cycling. This condition will be
evident. Air leakage into the discharge line indicates a ruptured diaphragm. Air
leakage from the exhaust port indicates leakage in the air distribution valve. See
further service instructions.
E. Blockage in the liquid chamber can impede movement of diaphragm.
F. Plugged or dirty exhaust muffler.
2. Pump cycles but will not pump
A. Suction side of pump pulling in air. Check the suction line for air leaks and be
sure that the end of the suction line is submerged. Check flange bolting. Check
valve flanges and manifold to chamber flange joints.
IMPORTANT
This pump is pressurized internally
with air pressure during operation.
Always make certain that all bolting is
in good condition and that all of the
correct bolting is reinstalled during
assembly.
Fig. 3 Pilot valve removal
Fig. 4 Pilot valve spool and o-rings
CAUTION
If a diaphragm fails, the pumped
product or fumes can enter the air side
of the pump. This side is exhausted
through the exhaust port (muffler).
When the product is a hazardous or
toxic material, the exhaust should be
piped to an appropriate area for safe
disposition.
When the product source is at a
higher level than the pump (flooded
suction), the exhaust should be piped
to a higher level than the product to
prevent spills caused by siphoning.