Maintenance
Page 17
Tsurumi’s Operation, Service, and Repair Manual
(7) If installed, remove shim (31) from bore in impeller (or remove shim from end of
engine crankshaft).
(8) Remove four bolts (14), spring washers (15), plain washers (16), and seals (17).
Remove casing cover (2) from the engine (33). Check the condition of seals (17) and
replace if damaged.
(9) Assemble the centrifugal pump according to the procedures in
Assembly of the
Centrifugal Pump
unless one of the following applies:.
(a)
If the pump has been disassembled to replace mechanical seal (7), refer to
4-8. Replacement of Mechanical Seal
for replacement procedures.
(b)
If the pump has been disassembled to replace cushions (23 or 24), refer to
4-9. Replacement of Cushions
for replacement procedures.
(c)
If the pump has been disassembled to remove or replace engine (33), refer to
4-10. Replacement of Engine
for replacement procedures.
4-7 Replacement of Mechanical Seal
A.
Description of the Mechanical Seal
(1) The mechanical seal (7) is a two part seal. The seal consists of a fixed element and
a rotating element.
(2)
The fixed element is installed in the center bore of the cover casing. The fixed ele-
ment is sealed between the seal and the center bore that is provided by a strip of
sealant on the outside diameter of the seal.
(3) The rotating element is installed in the center bore of the impeller. The rotating ele-
ment consists of a silicone-carbide mating ring and a close-fitting rubber cushion.
(4)
A static seal is provided between the pump casing and the volute casing.
B.
Removal of Mechanical Seal
(1)
Disassemble the pump only to the extent required to access the seal in casing cover
(2) and impeller (3). Refer to Remove Centrifugal Pump Components.
(2) Remove old mechanical seal (7) from casing cover (2) using a driver similar to the
driver in Figure 4-5.
NOTE:
•
Sealant is used on the outside diameter of mechanical seal (7). The sealant has a strong bond
in the casing cover bore and requires considerable driving force to remove the seal. Use of an
arbor press is therefore recommended.