dmf2dl5sm-rev0317
Model DMF2 Page 6
AIR INLET & PRIMING
For start-up, open an air valve approximately 1/2" to 3/4" turn. After the unit
primes, an air valve can be opened to increase flow as desired. If opening
the valve increases cycling rate, but does not increase flow rate, cavitation
has occurred, and the valve should be closed slightly.
For the most efficient use of compressed air and the longest diaphragm
life, throttle the air inlet to the lowest cycling rate that does not reduce flow.
A NOTE ABOUT AIR VALVE LUBRICATION
The SANDPIPER pump’s pilot valve and main air valve assemblies are
designed to operate WITHOUT lubrication. This is the preferred mode of
operation. There may be instances of personal preference, or poor quality
air supplies when lubrication of the compressed air supply is required. The
pump air system will operate with properly lubricated compressed air supplies.
Proper lubrication of the compressed air supply would entail the use of an
air line lubricator (available from Warren Rupp) set to deliver one drop of
10 wt., non-detergent oil for every 20 SCFM of air the pump consumed at
its point of operation. Consult the pump’s published Performance Curve to
determine this.
It is important to remember to inspect the sleeve and spool set routinely.
It should move back and forth freely. This is most important when the air
supply is lubricated. If a lubricator is used, oil accumulation will, over time,
collect any debris from the compressed air. This can prevent the pump from
operating properly.
Water in the compressed air supply can create problems such as icing
or freezing 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+PLUS:
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.
MODELS WITH 1" SUCTION/DISCHARGE OR LARGER,
AND METAL CENTER SECTIONS:
The main air valve sleeve and spool set is 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.
