SANDPIPER EB50M - Manual (Page 3)

520-035-000 2/02 Model EB2-M, EB2-MB, MEB2-M, EB50M Type 3 Page 3
Water in the compressed air supply can create problems such as icing or freez-
ing of the exhaust air causing the pump to cycle erratically, or stop operating. This
can be addressed by using a point of use air dryer to supplement a plant’s air drying
equipment. This device will remove excess water from the compressed air supply
and alleviate the icing or freezing problem.
ESADS: EXTERNALLY SERVICEABLE AIR DISTRIBUTION
SYSTEM
Please refer to the exploded view drawing and parts list in the Service Manual
supplied with your pump. If you need replacement or additional copies, contact your
local Warren Rupp Distributor. or the Warren Rupp factory Literature Department at
the number shown below To receive the correct manual, you must specify the MODEL
and TYPE information found on the name plate of the pump.
The main air valve sleeve and SpooI set Iist located in the valve body mounted on
the pump with four hex head capscrews. The valve body assembly is removed from
the pump by removing these four hex head capscrews.
With the valve body assembly off the pump, access to the sleeve and spool set is
made by removing four hex head capscrews (each end) on the end caps of the valve
body assembly. With the end caps removed, slide the spool back and forth in the
sleeve. The spool is closely sized to the sleeve and must move freely to allow for
proper pump operation. An accumulation of oil, dirt or other contaminants from the
pump’s air supply, or from a failed diaphragm, may prevent the spool from moving
freely. This can cause the spool to stick in a position that prevents the pump from
operating . If this is the case, the sleeve and spool set should be removed from the
valve body for cleaning and further inspection.
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 abra-
sions. 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 equiva-
lent. 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 ardor 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. Reinstall 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, reinstall the valve body on the pump using new gas-
kets. Tighten the four hex head capscrews evenly and in an alternating cross pattern.
PILOT VALVE
This assembly is reached by removing the air distribution valve body from the
pump and lifting the pilot valve body out of the intermediate housing.
When reinserting an externally serviceable pilot valve, push both plungers out of
the path of the pilot valve so that they and the pilot valve are not damaged.
Service Note: If a problem arises with the pilot valve, it is usually corrected by
replacing only o-rings. Always grease the spool prior to inserting into the sleeve. If
the sleeve is removed from the body, reinsertion must be from the same side it was
removed from, the chamfered side. Again, grease the o-rings so that it slides into the
body. Make sure the retaining ring has securely been inserted around the sleeve.
BEFORE OPERATION
Before pump operation, inspect all
gasketed fasteners for looseness
caused by gasket creep. Retorque loose
fasteners to prevent leakage. Follow
recommended torques stated in this
manual
DANGER
Before doing any maintenance on the
pump, be certain all pressure is
completely vented from the pump,
suction, discharge, piping, and all other
openings and connections. Be certain
the air supply is locked out or made non-
operational, so that it cannot be started
while work is being done on the pump.
Be certain that approved eye protection
and protective clothing are worn all
times in the vicinity of the pump. Failure
to follow these recommendations may
result in serious injury or death.