SANDPIPER PB1-A - Manual (Page 2)

PB1-A Type 3 Page 2 520-032-000 5/99
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.
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.
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.
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
7 /
8
" (2.22 cm) wrench on the outer plate
lugs. (If a socket is used, it must be a six point socket.)
The diaphragm assembly has been secured to the diaphragm rod with LOCTITE
242 Blue. This is to eliminate movement. During diaphragm servicing, the outer
diaphragm plate can be removed by turning the assembly counterclockwise, using a
7 /
8
" (2.22 cm) wrench on the outer diaphragm plate lug. (If a socket is used, it must
be a six point socket.) To replace the interior components consisting of shaft seals,
sleeve bearings and bearing retainers, the inner chambers must be disassembled
from the intermediate bracket by removing six capscrews.
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).
REASSEMBLY
To reassemble the diaphragm assembly, the threads of the outer diaphragm plate
must have LOCTITE 242 Blue applied to the threads before threading into the
diaphragm rod. Torque the diaphragm assembly to 25 ft. lbs. (33.90 Newton meters)
(see Fig. 4). Allow a minimum of 15 minutes to elapse after torquing, then re-torque
diaphragm assembly to 25 ft. lbs., compensating for stress relaxation in the clamped
assembly.
During reassembly make certain that the rubber bumper is on the rod at each side.
Install the diaphragm with the natural bulge outward as indicated on the diaphragm.
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 25 ft. lbs. (33.90 Newton meters). Torque while
Fig. 1 Air inlet
Fig. 2 Exhaust muffler
Fig. 4 Torquing of diaphragm
Fig. 3 Gaskets in place before reassembly