Specifications Information and Repair Parts Manual 3680, 3690 and 3700 Series
3680-250-00
2
1/2020
Centrifugal Pumps
SHIM ADJUSTMENT
1.
When installing a replacement adapter (Ref. No.4), impeller
(Ref. No. 8), or casing (Ref. No. 12) it may be necessary to
vary number of impeller shims (Ref. No. 7) that will be
required. This is easily done by adding one shim more than
was removed and reassembling pump as described in
“Mechanical Seal Replacement” section.
NOTE:
When adding or removing shims, it is best to proceed with a
0.010" increment each time. While tightening unit together turn shaft;
feel for shaft seizing. If shaft begins to seize before fasteners are
completely tight, disassemble pump and remove one shim and repeat
assembly.
2.
Once having added one shim more than original, ensure
that casing and adapter are firmly fitted (check fasteners
Ref. No. 13). When pump shaft turns freely, add shims until
it does strike, then remove a 0.010" shim. This should allow
proper clearance.
3.
Proper running clearance for impeller should be as close as
possible to volute without striking; maximum clearance is
1/32" (0.032").
4.
Follow above procedure until proper clearance is obtained.
This will ensure maximum performance.
