MDM C-SHELL 4X3 Installation And Service Manual page 6

1. Bracket Plate
a. Attach Bracket Plate (2) to motor face using Hex or Allen Head Fasteners (3) per torque specs (See Table B) with the drain slot pointed downwards.
b. Anti-seize (Item H) should be applied to the register face and motor screws to aid in disassembly.
2. Seal Installation
a. Referencing seal manufacturer's instructions, install Stationary Seal Face (7A) in the Seal Housing (4). Lightly lubricate outside rubber boot of
Stationary Seal Face (7A) with Molykote
Housing (4) counterbore gently by hand. Warning: Hard tools can damage the seal face and prevent proper operation. Ensure seal is firmly seated in
Seal housing (4). Inspect from the front and back of Seal Housing (4) to make sure seal is straight and fully seated (Figures 2 and 3).
b. Clean stationary seal bore with isopropyl alcohol and a lint free paper dry wipe and Isopropyl Alcohol (Item G) until all contaminates wipe clean
and alcohol evaporates.
c. Insert Seal Housing (4) into register fit on Bracket Plate (2) being careful not to nick or scratch stationary seal with motor shaft. The Seal
Housing (4) will not be positively retained at this point, so use extreme caution to prevent damage to seal components. Use a bent metal strap
or a 12" adjustable C-Clamp (Item O) to hold the seal housing to the bracket plate. Example of retainer shown in (Figure 4).
d. Lubricate rubber inside of Rotary Seal Face (7B) with a very light coating of Molykote® 111. Insert Shaft Sleeve (8) into Seal Spring (7C) and
Rotary Seal Face (7B) assembly with the Spring Retainer (7D) against the Shaft Sleeve (8) shoulder. See (Figures 5 & 6).
3. Shaft Sleeve Installation
a. Slide Shaft Sleeve (8) with seal components installed onto motor shaft with keyway aligned with key. The pentagonal side of the Shaft Sleeve (8) will
face away from the motor.
b. Seat Shaft Sleeve (8) firmly against the motor shaft shoulder. Ensure assembly will not fall off motor shaft.
c. Insert Square Key (9) into keyway and verify that the key does not protrude further than the Shaft Sleeve (8) shoulder. See (Figures 7 & 8).
4. Impeller Installation
a. Install Impeller (11) on the pentagonal side of the Shaft Sleeve (8).
b. Lightly lubricate Impeller Bolt O-Ring (17) with Molykote
c. Lightly lubricate Pentagon Hub O-Ring (13) with Molykote
d. Install Pentagon Hub Spacer (12), and Pentagon Hub (14) onto Shaft Sleeve (8) followed by Impeller Bolt (18), with Impeller Bolt Flat Washer (15)
and Impeller Bolt Lock Washer (16). Hold Pentagon Hub Spacer (12) relatively centered over the Shaft Sleeve (8). Tighten Impeller Bolt (18) with
an impact tool to avoid having to lock shaft. Verify that the Pentagon Hub Spacer (12) is centered.
e. If an impact tool is unavailable, motor fan cover and fan can be removed from the motor to access the shaft extension on the rear of the motor. This can
be held with a keyed shaft wrench (Table A) or an adjustable wrench while the shaft screw is tightened against it per torque specs (Table B).
5. Case (Volute) Installation
a. Fit Case (19) register over the Seal Housing (4) and insert Case Bolts (1C) through Case (19) and Bracket Plate (2).
b. For 4x3 and 6x5 pumps, fasten Case Nuts (1A) and Case Washers (1B) onto Case Bolts (1C) and torque according to the specifications found in (Table B).
c. For 3x2 pumps, torque Case Bolts (1C) according to the specifications found in (Table B).
6. Impeller Clearance Check
a. Verify rotation with minimal drag by hand. Some drag (i.e. soft scraping noise) is expected from Seal (7A-7D) and for the Impeller (11) to wear
into the Case (19). It may take a little torque to turn. If Impeller (11) is locked then tear back down and investigate.
b. Check clearance between Impeller (11) and Case (19) through discharge or suction openings. Ideal clearance is .020-.120". A tighter clearance
will provide higher efficiencies and slightly higher head values. See chart below for net clearance changes with various Case Gasket (6) and
Impeller Spacer (10) combinations. Do not stack spacers or gaskets above 2 tall.
c. If clearance is too tight, remove Case (19) and insert the Case Gasket (6).
Reassemble and verify clearance.
d. If clearance is too loose, remove Case (19), Impeller Bolt (18), Pentagon
Hub (14), Pentagon Hub Spacer (12) and Impeller (11). Remove the Impeller
(11) and place Spacer Shim (10) on the Shaft Sleeve (8) to achieve desired
clearance. Reassemble from Step 5.
7. Case O-Ring
a. Once clearance is verified, lightly grease case Case O-Ring (5) and fit into groove on Seal Housing (4). This step is withheld until now to prevent
damage to Case O-Ring (5) if disassembly and reassembly is required.
8. Verify rotation and final clearance.
9. Proceed to Start Up.
PROUDLY MADE
IN THE USA
4X3 GENERAL ASSEMBLY
®
® 111 Silicon Based Dielectric Grease (Item I) to ease assembly and press Stationary Seal Face (7A) into Seal
®
Generated from efficiency. Adapted for flow. Built for longevity.
111 Silicon Based Dielectric Grease (Item I) and fit into groove on Impeller Bolt (18).
111 Silicon Based Dielectric Grease (Item I) and fit into groove on Pentagon Hub (14).
®
SCENARIO
Standard: 1 gasket, 0 impeller spacer
Add Case Gasket
Remove Case Gasket
NET CLEARANCE CHANGE
0.000"
+0.032"
-0.032"
IMPELLER CLEARANCE CHART
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