Idex Blagdon Pump X75, Service And Operating Manual, Page: 8 / 38

x75mfvmdl2sm-rev0411 Page 6
A NOTE ABOUT AIR VALVE LUBRICATION
The 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 set to deliver one drop of 10 weight, 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 (available from Warren Rupp) 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.
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 Distributor, or the factory Literature Department at the number shown below. To receive
the correct manual, you must specify the MODEL 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.
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. 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 gaskets. Tighten the four hex head capscrews evenly and in an alternating cross pattern.