TM 10-4320-325-14
g. Secure with Teflon washer (2) and impeller locking bolt (1).
Note
When replacing seal, also replace volute O-ring (Item 7, Figure 4-8),
wear plate O-ring (Item 8, Figure 5-1), and four self-sealing screws (Item
11, Figure 5-1).
h. If a new impeller and/or wear plate is installed, or if the impeller clearance is to be changed,
determine the shim thickness to obtain a clearance of 0.01 to 0.015 inches (0.254 to 0.381 mm)
by the following procedure:
(1)
Screw impeller (3) clockwise on shaft adapter (9) without shims (4). Make sure impeller is
seated firmly against shaft shoulder. Secure impeller with Teflon washer (2) and impeller
locking bolt (1).
(2)
Measure from impeller face to wear plate face using a feeler gauge. Clearance should be
0.01 to 0.015 inches (0.254 to 0.381 mm).
(3)
Shims (4) are 0.01 inches (0.254 mm) thick and 0.005 inches (0.127 mm) thick. Add any
combination of shims to obtain proper clearance.
i. After proper clearance is obtained, tighten impeller locking bolt (1).
5-8
