Pompa ad Ingranaggi - Serie MX
Gear Pump - MX Series
43
1) Single seal (see Figure 1)
a) Access to the mechanical seal
After removing the feather key
from its seat, loosen the hexagonal head screws
of the
seal cover
and extract it, by paying attention not to damage the seal static part
,
housed in the cover. It is thus possible to check the state of wear and tear of the seal con-
tact surfaces. On reassembly, pay attention not to pinch the sealing O-ring
housed in the
cover.
b) Replacing static seal
To remove the static part of the seal
from the seal cover
, it is necessary exert a pres-
sure upon the external side of the seal. After placing the seal cover on a plane and greasing
the walls to make assembly easier, insert the new static seal with the relevant O-ring; use a
pad interposed with a soft bearing to exert the force perpendicularly to the cover.
c) Replacing dynamic seal
To remove the dynamic part of the seal
it is advisable to use an iron wire bent at 90° at
one end to hook the first or the second coil of the seal spring
. Exert a traction force paral-
lel to the shaft
, by paying attention not to scratch this last. After greasing the shaft to
make assembly easier, insert the new mechanical seal by rotating the spring in the direction
opposite to that of the coil; use a pad interposed with soft bearing to press the seal up to
make the spring
rest on the projection (or on the seeger
) provided on the shaft.
2) Double back-to-back seals (see Figure 2)
a) Access to the external mechanical seal
After removing the feather key
from its seat
, loosen the hexagonal head screws
of the ex-
ternal seal cover
and remove this last, by paying attention not to damage the static part of the
external seal
, housed in the cover. It is thus possible to check the state of wear and tear of the
external seal contact surfaces. On reassembly, pay attention not to pinch the sealing O-ring
housed in the cover.
b) Replacing static seals
To remove the static part of the external seal
from the seal cover
, it is necessary to ex-
tract, by using special pliers, the seeger ring
housed in the cover, remove the ball bearing
and exert a pressure upon the external side of the seal. After placing the seal cover on a
plane and greasing the walls to make assembly easier, insert the new static seal with the
relevant O-ring; use a pad interposed with a soft bearing to exert the force perpendicularly to
the cover.
To gain access to the static part of the internal seal, proceed as described at points
c)
.
Then, unscrew the socket screws
of the internal mechanical seal seat
A, by paying at-
tention not to damage the static part of the seal
, housed in the cover, and extract it, by exerting
a pressure upon the external side of the seal.
After placing the internal mechanical seal seat on a plane and greasing the walls to make
assembly easier, insert the new static seal with the relevant O-ring; use a pad interposed
with a soft bearing to exert the force perpendicularly to the cover.
c) Replacing dynamic seals
To remove the dynamic part of the external seal
it is advisable to hold the spring
and,
with a rotation movement in the same direction as that of its coil, exert a traction force paral-
lel to the shaft
A, by paying attention not to scratch this last. After greasing the shaft to
make assembly easier, insert the new mechanical seal by rotating the spring in the direction
opposite to that of the coil; use a pad interposed with a soft bearing to press the seal up to
make the spring rest on the stop ring
fixed on the shaft.
To replace the dynamic part of the internal seal
, it is necessary to disassemble the ring
, fixed on the shaft by means of threaded grub screws
.
We recommend to mark accu-
rately the ring position on the shaft before disassembly, so as to ensure the correct
seal pre-load later.
To remove the dynamic part of the internal seal
it is advisable to use
an iron wire bent at 90° at one end to hook the first or the second coil of the seal spring
.