SANDPIPER PB3-4-A User Manual

SERVICE AND OPERATING MANUAL

®

Model PB¾ - A

Type 3

PLEASE NOTE!

The photos 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 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 valve spool. This pushes
it into position for shifting of the air distribution valve.

The chambers are manifolded together with a suction and discharge check valve
for each chamber, maintaining flow in one direction through the pump.

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.

WARNING

Take action to prevent static sparking.
Fire or explosion can result, especially
when handling flammable liquids. The
pump, piping, valves, containers or
other miscellaneous equipment must be
grounded.

CAUTION

Operating temperature limitations are as
follows:

PFA ....... 212°F(100°C) Max to 0°F(-18°C)Min.

PVDF .... 200°F(93°C) Max to 10°F(-13°C)Min.

Nylon .... 120°F(48°C) Max to 32°F (0°C) Min.

Polypro 150°F(65°C) Max to 40°F (5°C) Min.

BEFORE OPERATION

Before pump operation, inspect all
gasketed fasteners for looseness
caused by gasket creep. Retorque loose
fasteners to prevent leakage prior to
start-up. Follow recommended torques
stated in this manual.

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 10 feet (3.05 meters) or
less. For suction lifts exceeding 10 feet of liquid, fill the chambers with liquid prior to
priming.

®

surge suppressor is recommended to further reduce

Figure 1: Air Inlet Capscrews

AIR SUPPLY

Air supply pressures cannot exceed 100 psi (6.89 bar). Connect the pump air inlet
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
(19mm) in diameter) between pump and piping to eliminate strain to pipes.

3

/4"

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 in-

WARREN RUPP, INC. A Unit of IDEX Corporation • P.O. Box 1568 • Mansfield, Ohio 44901-1568 USA • [phone] Fax [phone]

520-121-000 7/99 Model PB¾ -A Type 3 Page 1

creases 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.

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.

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 3/8" (.9525 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. Use exhaust kit 475-107-000 to pipe out exhaust.

Freezing or icing of the air exhaust can occur under certain temperature and
humidity conditions. Use of a Warren Rupp Extractor/Dryer unit should eliminate
most icing problems.

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 twelve capscrews 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.

WARNING

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.

CAUTION

In the event of diaphragm rupture,
pumped material may enter the air end
of the pump, and be discharged into the
atmosphere. If pumping a product which
is hazardous or toxic, the air exhaust
must be piped to an appropriate area for
safe disposition.

Figure 2: Exhaust cap assembly. (475-107-000)

DIAPHRAGM SERVICING

Remove the two V-Band clamps securing the outer chambers to the intermediate
housing. Remove the diaphragm assembly (outer plate, diaphragm, inner plate) by
turning the assembly counterclockwise using a 3/4" (1.91 cm) wrench on the outer
plate lugs. (If a socket is used, it must be a six point socket.) The interior components
consisting of the shaft seal and pilot valve assembly are now accessible for service.

Procedures for reassembling the diaphragms are the reverse of the above. Dur­ing reassembly make certain that the rubber bumper is on the rod on each side.
Install the diaphragm with the natural bulge outward.

Install the outer diaphragm plate on the outside of the diaphragm and make
certain that the large radius side of the inner plate is toward the diaphragm. Tighten
the outer diaphragm plate to approximately 90 in. lbs. (10.16 Newton meters).

Torque while allowing the diaphragm to turn freely with plates. Use a wrench on
the outer diaphragm plate of the opposite side to keep rod from rotating. If the
opposite chamber is assembled, the rod need not be held.

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

Figure 3: Check valve and seat.

Figure 4: Diaphragm and diaphragm plate.

Model PB¾ -A Type 3 Page 2 520-121-000 7/99

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.

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.

MODELS WITH SUCTION/DISCHARGE LESS THAN 1"

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 assembIy 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 spooI 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 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 his 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 suppiy 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, Iightly lubricate the o-rings on the sleeve
with an o-ring assembly lubricant or lightweignt 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, and retaining ring on the valve body. Using the arbor press or bench vise
that was used in disassembly, press the sleeve back into the valve body. Re-install
the spool, keeping the counter-bored end toward you, and install the spring, oppo­site end cap and retaining ring 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, at 70 in./lbs. (7.9 Newton meters).

CAUTION

Before maintenance or repair, shut off
the compressed air line, bleed the
pressure, and disconnect the air line
from the pump. The discharge line may
be pressurized and must be bled of its
pressure. When used for toxic or
aggressive fluids, the pump should
always be flushed clean prior to
disassembly.

Figure 5: Sleeve and spool set.

Figure 6: Disassembling the pilot valve.

PILOT VALVE ACTUATOR

The pilot valve spool (item 9C) contains 6 o-rings (item 9D). This spool moves
through the sleeve (item 9B). Check condition of o-rings for cuts or gouges before re­assembly. Apply a light coating of grease to the o-rings when inserting into the
sleeve. Insert spool into sleeve from chamfered side. The o-ring on the end should
be installed after the spool is in place (install last). Make sure the sleeve is locked
into the intermediate bracket (item 16) with retainer ring ( item 9E). Fig. 7.

Figure 7: Pilot valve with o-rings.

TROUBLESHOOTING

1. Pump wlll not cycle

A. Check to make sure the unit has enough pressure to operate and that the air inlet

valve is open.

B. Check the discharge line to insure that the discharge line is neither closed nor

blocked.

C. If the spool in the air distribution valve is not shifting, check the main spool. It must

slide freely.

D. Excessive air leakage in the pump can prevent cycling. This condition will be

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