SANDPIPER PB2-A User Manual

SERVICE AND OPERATING MANUAL
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Models PB11/2-A & PB2-A
Type 3
PLEASE NOTE!
The photos shown in this manual are for general instruction only. YOUR SPECIFIC MODEL MAY NOT BE SHOWN. Always refer to the parts list and exploded view drawing for your specific model when installing, disassembling or servicing your pump.
PRINCIPLE OF PUMP OPERATION
This ball type check valve pump is powered by compressed air and is a 1:1 pressure ratio design. It alternately pressurizes the inner side of one diaphragm chamber, while simultaneously exhausting the other inner chamber. This causes the diaphragms, which are connected by a common rod, to move endwise. Air pressure is applied over the entire surface of the diaphragm, while liquid is discharged from the opposite side. The diaphragm operates under a balanced condition during the discharge stroke, which allows the unit to be operated at discharge heads over 200 feet (61 meters) of water head.
Since the diaphragms are connected by a common rod, secured by plates to the center of the diaphragms, one diaphragm performs the discharge stroke, while the other is pulled to perform the suction stroke in the opposite chamber.
For maximum diaphragm life, keep the pump as close to the liquid being pumped as possible. Positive suction head in excess of 10 feet of liquid (3.048 meters) may require a back pressure regulating device. This will maximize diaphragm life.
Alternate pressuring and exhausting of the diaphragm chamber is performed by means of an externally mounted, pilot operated, four-way spool type air distribution valve. When the spool shifts to one end of the valve body, inlet air pressure is applied to one diaphragm chamber and the other diaphragm chamber exhausts. When the spool shifts to the opposite end of the valve body, the porting of chambers is reversed. The air distribution valve spool is moved by an internal pilot valve which alternately pressurizes one side of the air distribution valve spool, while exhausting the other side. The pilot valve is shifted at each end of the diaphragm stroke by the diaphragm plate coming in contact with the end of the pilot spool. This pushes it into position for shifting of the air distribution valve.
The chambers are manifolded together with a suction and discharge check valves for each chamber, maintaining flow in one direction through the pump.
INSTALLATION & START-UP
Locate the pump as close to the product being pumped as possible, keeping suction line length and number of fittings to a minimum. Do not reduce line size.
For installations of rigid piping, short flexible sections of hose should be installed between pump and piping. This reduces vibration and strain to the piping system. A Warren Rupp Tranquilizer pulsation in flow.
This pump was tested at the factory prior to shipment and is ready for operation. It is completely self-priming from a dry start for suction lifts of 15 feet (4.5 meters) or less. For suction lifts exceeding 15 feet of liquid, fill the chambers with liquid prior to priming.
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surge suppressor is recommended to further reduce
IMPORTANT
Read these instructions completely, before installation and start-up. It is the responsibility of the purchaser to retain this manual for reference. Failure to comply with the recommendations stated in this manual will damage the pump, and void factory warranty.
POSSIBLE EXPLOSION HAZARD can result if 1, 1, 1,-Trichloroethane, Methylene Chloride or other Halogenated Hydrocarbon solvents are used in pressurized fluid systems having Aluminum or Galvanized wetted parts. Death, serious bodily injury and/ or property damage could result. Consult with the factory if you have questions concerning Halogenated Hydrocarbon solvents.
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 non­operational, 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 at all times in the vicinity of the pump. Failure to follow these recommendations may result in serious injury or death.
AIR SUPPLY
Air supply pressures cannot exceed 100 psi (7.0 bar). Connect the pump air inlet (Fig. 1) to an air supply of sufficient capacity and pressure required for desired performance. When the air line is solid piping, use a short length of flexible hose not less than pipes. The weight of the air supply line and of the filter must be supported by some means other than the air valve cap. Failure to provide support may result in damage to the pump. A pressure regulating valve should be installed to prevent pressure from exceeding recommended limits.
WARREN RUPP, INC. A Unit of IDEX Corporation • P.O. Box 1568 • Mansfield, Ohio 44901-1568 USA • (419) 524-8388 • Fax (419) 522-7867
520-130-000 2/97 Model PB1½-A & PB2-A Page 1
1
/2" (12.7mm) in diameter between pump and piping to eliminate strain to
Fig. 1 Air inlet
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 (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.
CAUTION
Hydrofluoric acid above 40% concen­trate should not be pumped with the polypropylene unit. Check chemical compatibility chart for other fluids.
CAUTION
Operating temperature limitations are as follows:
PVDF:PVDF:
PVDF: 200°F (93.3°C) Max. to 10°F (-12.2°C) Min.
PVDF:PVDF: Polypro.:Polypro.:
Polypro.: 150°F (65°C) Max. to 40°F (4.4°C) Min.
Polypro.:Polypro.:
Fig. 2 Exhaust muffler
MODELS WITH 1" SUCTION/DISCHARGE OR LARGER, AND NON-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 a retaining ring (each end) securing the end cap on the valve body assembly. With the end caps removed, slide the spool back and forth in the sleeve. The spool is closely sizes 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 o­ring 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). Re­install one end cap, and retaining ring on the valve body. Using the arbor press or bench vise that was used in disassembly, body, without shearing the o-rings. Re-install the spool, opposite end cap and retaining ring 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, at 150 in./lbs. (16.94 Newton meters).
carefully press the sleeve back into the valve
Fig. 3 Check balls exposed
Fig. 4 Torquing the diaphragm plate
Fig. 5 Torque of diaphragms
Model PB1½-A & PB2-A Page 2 520-130-000 2/97
PILOT VALVE
The pilot valve assembly is accessed by removing the main air distribution valve body from the pump and lifting the pilot valve body out of the intermediate housing (See Fig. 10).
Most problems with the pilot valve can be corrected by replacing the o-rings. Always grease the spool prior to inserting it into the sleeve. If the sleeve is removed from the body, reinsertion must be at the chamfered side. Grease the o-rings to slide the sleeve into the valve body. Securely insert the retaining ring around the sleeve. When reinserting the pilot valve, push both plungers (located inside the intermediate bracket) out of the path of the pilot valve spool ends to avoid damage.
PILOT VALVE ACTUATOR
Bushings for the pilot valve actuators are held in the inner chambers behind the diaphragms. The plunger may be removed for inspection or replacement. First remove the air distribution valve body and the pilot valve body from the pump. The plungers can be located by looking into the intermediate. It may be necessary to use a fine piece of wire to pull them out. The bushing can be turned out through the inner chamber by removing the outer chamber assembly. Replace the bushings if pins have bent.
AIR EXHAUST
If a diaphragm fails, the pumped liquid or fumes can enter the air end of the pump, and be exhausted into the atmosphere. When pumping hazardous or toxic materials, pipe the exhaust to an appropriate area for safe disposition (see Fig. 2).
This pump can be submerged if materials of construction are compatible with the liquid. The air exhaust must be piped above the liquid level. Piping used for the air exhaust must not be smaller than 1" (2.54 cm). Reducing the pipe size will restrict air flow and reduce pump performance .When the product source is at a higher level than the pump (flooded suction), pipe the exhaust higher than the product source to prevent siphoning spills.
Freezing or icing of the air exhaust can occur under certain temperature and humidity conditions. Use of a Warren Rupp Air Dryer unit should eliminate most icing problems.
Fig. 6 Gaskets / o-rings
Fig. 7 Gaskets / o-rings
BETWEEN USES
When used for materials that tend to settle out or transform to solid form, the pump should be completely flushed after each use, to prevent damage. Product remaining in the pump between uses could dry out or settle out. This could cause problems with valves and diaphragms at re-start. In freezing temperatures, the pump must be drained between uses in all cases.
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.
Remove the four V-Band clamps securing the manifold assemblies to the outer chambers. Inspect the surfaces of both check valve and seat for wear or damage that could prevent proper sealing. If pump is to prime properly, valves must seat air tight (see Fig. 3).
DIAPHRAGM SERVICING
Remove the four V-Band clamps securing the manifold assemblies to the outer chambers. Remove the two V-Band clamps securing the outer chambers to the inner chambers. Remove the diaphragm assembly (outer plate, diaphragm, inner plate) by turning the assembly counterclockwise using a 1 plate lugs. For the PB2, use a 1½" (3.8 cm) wrench. To disassemble the diaphragm assemblies, lock the inner plate in a soft jaws vice and turn the outer plate counterclockwise from the inner plate using the same wrench. Be sure inner plate is free of burrs. The interior components consisting of shaft seals, sleeve bearings and bearing retainers are now accessible for service.
3
/8" (3.492 cm) wrench on the outer
Fig. 8 Gasket, item 63, used only on polypro­pylene models.
Fig. 9 Sleeve & spool exposed.
520-130-000 2/97 Model PB1½-A & PB2-A Page 3
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