SANDPIPER PB1/2-A - Manual (Page 4)

Model PB½ -A Type 3 Page 4 520-041-000 2/99
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 re-
assembly. 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.
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
evident. Air leakage into the discharge line indicates a ruptured diaphragm. Air
leakage from the exhaust port indicates leakage in the air distribution valve. See
further service instructions.
E. Blockage in the liquid chamber can impede movement of diaphragm.
2. Pump cycles but wlll not pump
A. Suction side of pump pulling in air. Check the suction line for air leaks and be sure
that the end of the suction line is submerged. Check flange bolting. Check valve
flanges and manifold to chamber flange joints.
B. Make certain the suction line or strainer is not plugged. Restriction at the suction
is indicated by a high vacuum reading when a vacuum gauge is installed in the
suction line.
C. Check valves may not be seating properly. To check, remove the suction line and
cover the suction port with your hand. If the unit does not pull a good suction
(vacuum), the check valves should be inspected for proper seating.
D. Static suction lift may be too high. Priming can be improved by elevating the
suction and discharge lines higher than the check valves and pouring liquid into
the unit through the suction inlet. When priming at high suction lifts or with long
suction lines operate the pump at maximum cycle rate.
3. Low performance
A. Capacity is reduced as the discharge pressure increases, as indicated on the
performance curve. Performance capability varies with available inlet air supply.
Check air pressure at the pump inlet when the pump is operating to make certain
that adequate air supply is maintained.
B. Check vacuum at the pump suction. Capacity is reduced as vacuum increases.
Reduced flow rate due to starved suction will be evident when cycle rate can be
varied without change in capacity. This condition will be more prevalent when
pumping viscous liquids. Viscosity is limited to a maximum of 10,000 SSU. When
pumping thick, heavy materials the suction line must be kept as large in diameter
and as short as possible, to keep suction loss minimal.
C. Low flow rate and slow cycling rate indicate restricted flow through the discharge
line. Low flow rate and fast cycling rate indicate restriction in the suction line or air
leakage into suction.
D. Unstable cycling indicates improper check valve seating on one chamber. This
condition is confirmed when unstable cycling repeats consistently on alternate
exhausts. Cycling that is not consistently unstable may indicate partial exhaust
restriction due to freezing and thawing of exhaust air. Use of an anti-freeze lubri-
cant in an air line lubricator should solve this problem.
For additional information, see the Warren Rupp Troubleshooting Guide.
WARRANTY
This pump is warranted for a period of five years against defective material and
workmanship. Failure to comply with the recommendations stated in this manual
voids all factory warranty.
©1999 Warren Rupp, Inc. All rights reserved.
®SandPIPER and Tranquilizer are registered tradenames of Warren Rupp, Inc.
®Neverseize is a registered tradename of Loctite
Printed in U.S.A.
IMPORTANT
This pump is pressurized internally with
air pressure during operation. Always
make certain that all bolting is in good
condition and that all of the correct
bolting is reinstalled during assembly.
RECOMMENDED
WARREN RUPP ACCESSORIES
TO MAXIMIZE PUMP
PERFORMANCE:
• Tranquilizer ® Surge
Suppressor. For nearly
pulse-free flow.
• Warren Rupp Air Dryer. For
clean, dry compressed air.
• WarrenRupp Filter/Regulator.
For modular installation and
service convenience.
• Warren Rupp Speed Control.
For manual or programmable
process control. Manual
adjustment or 4-20mA
reception.
For more detailed information
on these accessories, contact
your local Warren Rupp
Factory-Authorized Distributor,
or Warren Rupp corporate
headquarters.