Specifications

14
BLB Series
Disassembly
Refer to Diagram 3 on Page 11.
Note: As parts are disassembled, place
them carefully on a clean surface such
as a soft cloth. Do not allow them to
knock together.
1) Remove Drive Strap Screws (28) and
Drive Strap (20). Remove Seal Plate
Screws (41) and Seal Plate (19) and
remove the Outer Drive Gear (1).
2) Remove Seal Housing (13) and Lip
Seals (14) in the housing. In all cases
we strongly advise removing and dis-
carding used Lip Seals (14).
3) For pumps with a mechanical face
seal, remove Outer Drive Gear (1) by
first removing Drive Strap Screws
(28), Drive Strap (20) and Outer Drive
Shaft (11). Remove Coupling Housing
Screws (41) and Seal Plate (2) to
allow outer drive gear to be removed.
4) With the pump ports facing upward,
clamp the sides of the Front Side
Plate (2) in a vise. Note: Never clamp
the pump on a lapped surface.
Loosen the four 1/2-13 Binder Screws
(21) and remove two diagonal screws
completely. Back the other two
screws out until only one or two
threads are engaged.
5) Remove the pump from the vise and
lay it on its long side on the bench.
Separate the Front Side Plate (2),
Center Plate (4) and Rear Side Plate
(3) by gently tapping the engaged
Binder Screws (21) with a plastic
hammer. Some process fluids make
disassembly difficult, and a soft-face,
dead blow hammer may have to be
used in these cases.
6) After the plates are apart, completely
remove the partially engaged Binder
Screws (21). Pull the Front Plate (2)
off the Dowels (10) and carefully
remove the Drive Shaft (5), Key (8)
and Metering Gears (6 & 7). Never
pry the pump parts with a screwdriver
or similar tool or use pliers to lift the
gears.
7) The Center Plate (4) may, at times, be
difficult to separate from the Rear Side
Plate (3). If this is the case, it can
sometimes be loosened by jarring the
dowel ends against a table top. To do
this, grasp the Center Plate (4) and,
with the Rear Plate (3) upward, give
a downward thrust with the plates
parallel to the table top. If this doesn’t
work, the Dowels (10) must be
pressed out in the direction from the
Rear Plate (3) through the Center
Plate (4).
8) If the Arbor (9) or Hollow Dowels (10)
are to be replaced or checked, use
an arbor tool and press toward the
inside of the pump (the shortest press
distance). If there is residue present
on the surfaces of the front and rear
side plates, it is better to remove the
Arbor (9) and Dowels (10) in order
to hand lap, or “block” the plates as
described earlier.