Shaft Seal Block - mycom 3225**C Series Instruction Manual

5.5.11 Shaft Seal Block

The standard mechanical seal assemblies used in the current shaft seal of
screw compressors are of the BBSE (balance bellows single) type. There are other cases where the
BOS (balance O-ring single) type seals are used, according to the specification by the customer.
a) Before installing the mechanical seal, clean the seal
installation area on the rotor shaft. In particular,
immediately prior to the assembly, check again that
no flaw is present on the step area of the shaft where
the seal is to be installed.
b) Install the oil seal [50] on the seal retainer [48]. The
installation orientation of the oil seal has been
reversed in November 2002 as a design change.
While the oil seal had been installed with the oil seal
lip facing the direction of the atmosphere, the
direction was reversed. This is because excessively
high pressure should be avoided by helping the
escape of oil from the seal box.
Using a Teflon block or the like as a pad (Photo 105),
lightly hit the pad to push the oil seal evenly into the
retainer until it is fully seated. Once the oil seal is
fully inserted, you can easily sense it as the hitting
sound as well as the response will change.
After the installation, check that the level difference
with the retainer is uniform and that the oil seal is
evenly inserted by observing the condition from the
opposite side.
c) Insert the O-ring [744] into the inner circumference of
the oil seal sleeve [528], and install the sleeve into
the oil seal retainer with an O-ring inserted as shown
in Photo 106.
Compound 2-stage Screw Compressor 3225**C
Figure 5-18 BBSE-type Mechanical Seal
5-57
2202MYJE-MY-C8-N_2018.02.
Chapter 5 Maintenance and Inspection
Photo 105
Photo 106
5.5 Reassembly
standard