
UNIBLOC-PD Operation & Service Manual: PD600-677 17
ROTATING SEAL FACES
ROTORS & PINS
ROTATING SEAL O-RINGS
STATIONARY SEAL FACES
ROTOR HOUSING
SHAFTS
BEARING HOUSING
STATIONARY SEAL O-RINGS
STATIONARY SEAL FACE HOLDERS
RETAINING RINGS
RETAINING RING O-RINGS
REAR VEW- ROTOR HOUSING
FRONT VEW- ROTOR & BEARING HOUSING
REAR ROTOR HOUSING STUD NUTS
fig. 4.5
4.4.2 Single Mechanical Seal
This type of shaft seal is used in most applications with products that have a viscosity of less than 14,000 cPs. The
maximum rotational speed of this seal is 600 rpm and the maximum service pressure is 20.7 bar (300 psig). The seal
materials available are stainless steel, carbon, and silicone carbide. The standard o-rings supplied in these seals are
Viton or EPDM, either food or FDA grade, but may be replaced with other materials as applications dictate. The seal
can be serviced without removing the rotor housing.
4.4.2.1.1 Single Mechanical Seal Removal- MODELS: PD600, PD650, PD675
(reference figs. 4.1, 4.5)
Slide the stainless steel
Rotors
off the shafts. If the rotors will not slide off they can be removed simultaneously with
the
Rotor Housing
. Unless they are being replaced,
DO NOT USE PLIERS OR CHANNEL LOCKS TO REMOVE
THE ROTORS. THEY WILL BE DAMAGED.
The
Rotating Seal Faces
,
Pins
, and
Rotating Seal O-rings
are
assembled inside the
Rotors
and will slide out with them. Slide the
Stationary Seal Face
,
Stationary Seal O-rings
,
and
Stationary Seal Holders
out of the housing. To avoid damage, handle and store the loose
Rotating Seal Faces
and the
Stationary Seal Faces
so that their lapped sealing surfaces do not get scratched. If servicing the
Bearing
Housing
, remove the
Rotor Housing
by first loosening the
Rear Rotor Housing Stud Nuts
. Use a hoist and eye bolt
to support the
Rotor Housing
. Tap on the ports with a rubber mallet and pull the
Rotor Housing
off. Unless being
serviced, the
Retaining Rings
may remain attached to the
Rotor Housing
.
4.4.2.1.2 Single Mechanical Seal Installation- MODELS: PD600, PD650, PD675
(reference figs. 4.1, 4.5, 4.15)
Clean all components prior to installing the seals. If the
Rotor Housing
was removed, attach it to the
Bearing
Housing
first. Make sure
Retaining Rings
with
Retaining Ring O-rings
are attached to the
Rotor Housing
. Using
an eye bolt, hoist the rotor housing on the
Dowel Pins
(see fig. 4.15 on pg. 24) and slide it on, while at the same time
threading on the
Rear Rotor Housing Stud Nuts
. Tap the
Rotor Housing
with a rubber mallet to seat it properly
against the Bearing Housing. Tighten the
Rear Rotor Housing Stud Nuts
in a cross pattern. Place the
Stationary
Seal Face Holders
against the
Stationary Seal Faces
so that the pins slide into the slots. Moisten the
Stationary
Seal O-rings
with water or coat them with a lubricant that is acceptable for contact with the product. Slide these
components in the rotor housing bores. If removed from the rotors, lubricate
Rotating Seal O-rings
and slide them
in the rotors together with the
Rotating Seal Faces
locating them on the seal pocket
Pins
on the back side of the
the
Rotors
. The
Rotating Seal Faces
must be pressed in evenly so that the
Rotating Seal O-rings
do not come off.
They have been installed correctly if they do not fall out when tilting the rotors. Do not use objects that will scratch
the
Rotating Seal Faces’
surface to push them in. Place a product compatible lubricant on the sealing surfaces of
the
Stationary Seal Faces
and
Rotating Seal Faces
. Slide the
Rotors
on the
Shafts
. Proceed to section 4.4.6 to
complete the installation.