Remove the idler and bushing assembly from the pin.
Inspect for signs of excessive pin, head, idler and/or
bushing wear. Replace any worn parts Note the pin
grease groove position. If applicable, prior to removing.
Remove the packing gland.
If you have a mechanical seal pump, remove the end
cap and the mechanical seal is exposed.
Remove the mechanical seal by sliding off the end of
the shaft. Loosen the set screws In the set collar
through the connection provided and remove it.
Carefully remove the rotor and shaft from the pump.
Avoid damaging the casing or rotor bearing sleeve
If the casing, rotor bearing sleeve bushing and/or rotor
show signs of excessive scouring or wear they should
Remove the packing and press the rotor bearing sleeve
bushing out through the stuffing box area. Note that the
rotor bearing sleeve for the Q, M, N and R pumps Is
bolted to the casing as a sub-assembly. This can be
removed to facilitate easier handling if the bushing must
be replaced. Mark its position prior to removing.
Should it be necessary to install new
carbon bushings. extreme care should be
fracturing. It is a brittle material and easily
cracked. If cracked, these bushings will
quickly disintegrate. An arbor press
should be used to install carbon bushings.
Be sure the bushing is started straight and
do not stop the pressing operation until
the bushing is in the proper position.
invariably results in bearing failure.
Carbon bushings for high temperature
interference fits and must be Installed by
an arbor press after heating the bearing
bracket or idler to 450°F. Check the
bushing for cracks after installation.
Press the bearing housing bushing into place and
check the after press fit size to ensure clearance (as
specified in item 9) exists between the bushing and
shaft. Lubricate prior to startup For Q., M, N and R
pump models the rotor bearing sleeve can be
reassembled on to the casing.
Remove all burrs and rough surfaces from the rotor
and shaft and assemble in the casing. Start the shaft
through the casing or rotor bearing sleeve bushing and
slowly turning the rotor, push it into the casing as far
as it will go.
Press the idler bushing into the idler and ensure
clearance (as specified in item 9) exists between the
bushing and pin. Replace the idler disc if one was
originally supplied. Replace the Idler pin, if necessary,
positioning the grease groove as noted In the
disassembly. Place the idler assembly onto the head
and lubricate the bushing to pin area prior to start up.
Place the head gaskets on the head. The proper
amount of gaskets should be used to provide the
necessary end clearance within the pump so It turns
freely with no appreciable end play.
The head can now be assembled on the pump. Tilt
the top of the head away from the pump slightly until
the crescent enters the Inside diameter of the rotor
and rotate the idler until its teeth mesh with the rotor
teeth. Do not damage the head gaskets. Check that
the head and casing position markings are aligned
Tighten the head capscrew or nuts evenly and then
check the end clearance. If the pump shaft cannot be
rotated, more gaskets must be added. If, however, the
pump has any noticeable end play, remove enough
gaskets so the pump has no appreciable end play but
still turns freely.
Pack the pump. It is good practice to install a set of
new packing. A packing suitable for the liquid being
be used. If the pump has a lantern ring it must be
located below the grease fitting or flushing connection.
The grease fitting may be removed to facilitate
positioning of the lantern ring. Cut the packing into
individual rings that wrap exactly around the shaft.
Install and seat each ring one at a time staggering the
ring joints from one side of the shaft to the other.
Lubricate the packing rings with oil, grease or graphite
to aid In assembly. A length of pipe or tubing will help
in seating the packing rings.
Install the packing gland and nuts. The gland must
enter the stuffing box at least one-eighth of an Inch after
tightening the packing gland nuts Be sure the packing
does not wedge between the stuffing box and the gland,
as this may split the stuffing box.
Install the mechanical seal: Place the set collar on the
shaft and tighten setscrews. The seal is simple to
Install and good performance will result if care is taken
in its installation.
Never touch the sealing faces with anything
except the fingers or a clean cloth. Spread
a film of lubricating oil on the inside
diameter of the synthetic rubber bellows
Check the end of the pump shaft for sharp
burrs or edges which might cut the
bellows. Slide the seal rotary member over
the shaft and up against the setcollar. The
spring washer and spring must be put on
the shaft first and in that order. Coat the
synthetic rubber seal seat with lubricating
oil and push the seal seat into the end cap
Put the end cap gasket on the end of the
casing. Slide end cap over the shaft and
flush both the seal seat and carbon wear
ring in the seal rotary member with oil Push
the end cap up until the mating surfaces of
the seal meet. Install the capscrews then
Recommended minimum bushing clearances:
H & HX4
L - LO -
Q & M
The after press fit value is the final size for
carbon bushings. No sizing should be
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