SANDPIPER SET2-A - Manual (Page 3)

520-117-000 5/99 Model SET2-A Type 3 Page 3
Remove the spool from the sleeve. Using an arbor press or bench vise (with an improvised
mandrel), press the sleeve from the valve body. Take care not to damage the sleeve. At
this point, inspect the o-rings on the sleeve for nicks, tears or abrasions. Damage of this
sort could happen during assembly or servicing. A sheared or cut o-ring can allow the
pump’s compressed air supply to leak or bypass within the air valve assembly, causing
the pump to leak compressed air from the pump air exhaust or not cycle properly. This
is most noticeable at pump dead head or high discharge pressure conditions. Replace
any of these o-rings as required or set up a routine, preventive maintenance schedule
to do so on a regular basis. This practice should include cleaning the spool and sleeve
components with a safety solvent or equivalent, inspecting for signs of wear or damage,
and replacing worn components.
To re-install the sleeve and spool set, lightly lubricate the o-rings on the sleeve with
an o-ring assembly lubricant or lightweight oil (such as 10 wt. air line lubricant). Press the
set into the valve body easily, without shearing the o-rings. Re-install one end cap, gasket
and bumper on the valve body. Using the arbor press or bench vise that was used in
disassembly, press the sleeve back into the valve body. You may have to clean the surfaces
of the valve body where the end caps mount. Material may remain from the old gasket.
Old material not cleaned from this area may cause air leakage after reassembly. Take
care that the bumper stays in place allowing the sleeve to press in all the way. Re-install
the spool, the opposite end cap, gasket and bumper on the valve body. After inspecting
and cleaning the gasket surfaces on the valve body and intermediate, re-install the valve
body on the pump using new gaskets. Tighten the four hex head capscrews evenly and
in an alternating cross pattern.
OPErATiON
Your SandPIPER pump has been tested prior to shipment and is ready for use as
received. It is completely self-priming and no initial filling with fluid is required.
If the unit is to be totally submerged, the air exhaust must be piped above the liquid
level to prevent the liquid and foreign material from entering the air distribution valve
mechanism.
Open the inlet air valve at least one turn to allow sufficient cycling rate for the pump
to prime (30 to 60 cycles per minute). After pumping starts, adjust the inlet air valve
for the desired pumping capacity. When further opening of the inlet air valve increases
cycling rate without increasing the flow rate, the pump is being starved of liquid due to
suction limitations. Further opening of the air inlet valve will waste compressed air. Set
the inlet air valve for lowest cycling rate that does not decrease flow rate for most efficient
operation.
frEEZiNG Or iciNG Of EXHAUST
Icing of the air exhaust can occur under certain conditions of temperature and
humidity on compressed air power equipment. When pump performance suffers because
of icing, use of an air dryer will solve the problem. Icing is more likely to occur at high
discharge pressures.
Air EXHAUST
SandPIPER pumps can be submerged if the materials of construction are compatible
with the liquid and the exhaust is piped above the liquid level. (See OPErATiON, above.)
Piping used for the exhaust should not be smaller than 1" pipe size. Reduced pipe size
can restrict the exhausted air and reduce pump performance.
cHEcK VALVE SErViciNG:
Need for inspection or service is usually indicated by poor priming, unstable cycling,
reduced performance or the pump’s cycling but not pumping.
DiAPHrAGM SErViciNG:
Driver Diaphragms
Drain the driver diaphragm chamber by removing the boss plug on the underside
of the driver chamber. Remove eight bolts securing the two manifolds to the chambers.
Remove eight bolts securing the diaphragm chamber. This permits inspection of the Teflon
diaphragm and the driver diaphragm. Loosen the plate 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.