Hale 2CBP - Manual (Page 28)

Booster Pumps
Sec III- 8 Preventive Maintenance
performance has dropped appreciably
compared to its original performance, it
needs to be serviced. (Apparatus test
results should be on file with the delivery
documents. If not, they may be obtained
from the apparatus manufacturer or from the
original certifying authority.)
Worn Clearance Rings and Impeller Hubs
Because clearance ring replacement requires
pump disassembly, it is advisable to thoroughly
check other possible causes of low performance
before assuming that clearance ring wear is at
fault.
Clearance rings limit the internal bypass of
water from the discharge side of the pump back
to the suction. The radial clearance between
the impeller hub and the clearance rings is only
a few thousandths of an inch when new. In clear
water, the clearance rings continue to effectively
seal for hundreds of hours of pumping. In dirty
or sandy water, the impeller hub and clearance
rings will wear faster. The more wear, the
greater the bypass and lower pump
performance.
When new, the radial clearance between the
impeller hubs and the clearance ring is from
0.005 to 0.007 inch per side. Any increase will
allow more bypass and result in lower
performance. It should not be necessary to
replace clearance rings and impellers until the
average radial clearance reaches 0.015 to 0.020
inch or more per side, as measured with
calipers. Refer to Table 3-2.
If the clearance rings on the CBP pump show
significant wear but the impeller itself is within
the size tolerance, "undersized " clearance rings
can be installed to delay a complete rebuild.
Contact Customer Service at Hale Products and
refer to part 321-0070-01-0 for CBP
Often, replacement of the clearance rings will
reduce the bypass and restore the pump to near
original performance. A complete restoration
requires that the impellers also be replaced. See
Section V for maintenance and repair
information if pump disassembly is required.
EXTREME CONDITIONS
MAINTENANCE GUIDELINES
Freezing Weather
Drain the pump body and discharge valves. If
the gearbox is equipped with a water cooling
line, drain this line also. There should be drains
for the gauge lines, the cooling line to the
engine, and to the relief valve (if equipped). All
of these should be opened until all water is
drained out, then close the drain valves.
In freezing weather, drain the pump as follows:
1. Open the discharge and suction valves,
remove suction tube caps and discharge
valve caps.
2. Open the pump body drain cocks and drain
valves
3. After the pump is completely drained replace
all caps and close all valves.
Contaminated Water
After pumping salt water, contaminated water or
foam solution, or if water containing sand or
other foreign matter has been used, connect the
pump to a fresh water hydrant or other source of
fresh clean water and flush the contaminants
out of the pump.