MXM_Manual

13 Disassembly and Assembly of Pump

Caution!

Since the magnets used in the pump are powerful, be careful not to catch your fingers or hand between them during disassembly or assembly. Also, keep the magnet unit away from any electronic device that could be affected by a strong magnetic field.

Prior to servicing, the suction and discharge valves must be closed. The piping and the pump often retain some liquid. It is recommended the piping and pump cavity be drained prior to servicing.

If dangerous liquid is used, wear protection and flush pump with clean water or decontaminant prior to service.

Make sure power to motor is OFF.



Disassembly

1. Remove the drain and vent caps (122.1) to discharge the liquid from the pump. Flush the inside of the pump with a neutralizing fluid. [Fig. 7]

Vent Cap

2. Remove the hex head or socket bolts (903.1 & 903.2) and pull the front casing straight forward to detach from the frame (19). [Fig. 8 & 9] Be careful not to damage the spindle when removing the front casing. The spindle may come off with the front casing. If this happens, take care to no lose the rear thrust collar (314.1).

Figure 7

Caution! Strong impacts may crack the shaft or liner. Do not hit them with a tool.

Figure 8

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Figure 9

3. Remove impeller (2) and inner magnet assembly (230) from the containment shell (231) by drawing it forward. Be careful not to scratch the surface of each part. Since the inner magnet assembly is strongly magnetized, store it in a place free of metal pieces. Handle the front casing liner

(1.3), inner magnet assembly and impeller with extra care so as not to scratch the bushing and sealing surfaces. [Fig. 10]

4. To remove rear casing, insert a flat head screw driver into the periphery of the rear casing and slightly twist the screw driver. If the spindle remains in the front casing liner, remove if from the front casing. [Fig. 11]

5. Remove spindle from rear casing, while firmly grabbing spindle, simultaneously pull and wiggle the spindle. If necessary, submerge spindle where fixed to casing in hot water (194º F / 90º

C) for approx. 5 minutes.

Figure 10

6. To disassemble impeller and magnet capsule assembly, turn the locking pins counter clockwise 90 degrees using a slotted screw driver and then push it towards the inside of the impeller. [Fig.

12] If it is hard to push it out, slightly tap the end of the screwdriver handle.

If the screw- driver cannot be used because the groove of the pin was crushed, turn the pin from inside of magnet capsule using hex wrench. [Fig. 13] When doing so, turn the wrench clockwise. After turning the pin, push it in from the outside using a screwdriver or drive pin.

After the two locking pins are removed, remove the impeller from the magnet capsule by slightly tapping the periphery of the impeller with a plastic hammer. If it is hard to remove, warm it with hot water (approx.

194º F / 90º C) for five minutes and remove it by slightly tapping the impeller as described above. Pay attention to not burn yourself. If impeller

Figure 11 is forced from magnet capsule before the locking pins are removed, the impeller and magnet capsule may be damaged.

Figure 12

7. Remove the drive magnet assembly (232). Stand the motor up and remove two M8 hex head socket set screws (908.1) from the access hole in the frame (19). Insert a screwdriver and apply it to the boss (lower portion) of the outer magnet assembly and pull or lever the unit upwards. [Fig. 14] Store the magnet assembly in a proper place so that metal pieces, etc.are attracted to it.

Caution! Do not strike the outer magnet assembly.

Direct impact may loosen magnet strips or damage the motor bearings. the

Figure 13

Figure 14

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8. Replacement of Bushing, Mouth Ring

Bushing

1. Warm the inner magnet assembly (230) in hot water at 194° F (90° C) for approximately 5 minutes. Then using a hand (arbor) press, remove the bushing (237) by pressing the replacement jig from the front end of the inner magnet assembly. [

Fig. 15] (Consult Iwaki America for jig specifications).

Figure 15

* Bearing is pressed in from far end of magnet capsule.

2.

replacement jig to press the bushing into the inner magnet with the hand

(arbor) press. (If the inner magnet is cold, warm it as in step 1 above prior to pressing in the bushing).

3. After pressing in the new bushing, ensure that it is seated at the top and protrudes from the bottom of the inner magnet assembly.

Mouth Ring:

1. Heat weld tabs that are folded over mouth ring on impeller (2).

2. Remove the outboard thrust collar by applying a screwdriver to the bottom of it and lift upwards.

3. Place a new outboard thrust collar into the impeller by aligning the recessed areas of the outboard thrust collar with the mating surfaces of the impeller and press using the hand (arbor) press. Ensure that the outboard thrust collar is completely seated against the recess in the impeller.

COVER C

FRONT CASING

LINER

Front Casing Liner:

1. Remove the drain and vent caps (121.1).

2. Remove the four hex socket bolts (903.5).

3. Remove the two hex socket bolts (90.4) and separate Cover C (1.2) [ Fig. 16].

* Note: Cover C is divided into two halves. The two make a single set.

4. Remove the three hex socket bolts (903.3) and separate Cover A (1+1.1).

*Note: Cover A is divided into two halves. The two pieces make a single set.

Figure 20

COVER A

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Detach the front casing liner from Cover A. If this is difficult due to corrosion or rust on the cover, use a resin hammer and gently tap the suction port of the front casing. (This step completes disassembly of the front casing liner).

*Note: Cover A should always be stored as a single unit.

Cover B

Cover A

Front Casing

Cover A

Cover C

Figure 17

Figure 21

5. Align and install a new front casing liner into cover A, paying attention to the drain port and locating tabs. [Fig. 17] If the front casing liner is difficult to attach, tap it gently with a resin hammer. *Note: Tapping the back portion of the front casing liner may cause sealing difficulty during reassembly.

6. Attach and temporarily secure both halves of Cover A with the hex socket bolts

(903.3).

7. Attach and temporarily secure the two halves of Cover C (1.2) to Cover A (1 + 1.1) with the hex socket bolts (17). Tap the two parts gently in a slanted direction from the front casing liner suction port. [Fig. 16]

8. Align Covers A and C and secure all hex socket bolts tightly.

9. Insert gasket (73.2) into the vent and drain caps (122.1) prior to installing them.

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

Reassembly

Reassemble the pump by reversing the order of disassembly. Refer to the exploded view diagram on page 23 for parts and locations. Pay attention to the following points:

1. Replacement of o-ring and gasket

When reassembling pump, always replace the o-ring and gaskets. In addition, confirm that the oring and gaskets are not twisted or pinched by another part.

The sealing section should be cleaned free of dust or scratches before installation.

2. Fastening of bolts

Fasten the front casing bolts in a diagonal order, applying an equal torque to each.

Fastening Torque

Model Type Size of Bolt

Nm Kgf/cm Lbf/in

220, 221

441, 442, 542, 543, 545

Hex socket head bolt

12.5

24.5

127

250

111 M8

217 M10 x 80, M10 x 40

5.

3. Ceramic type

For pumps containing a ceramic bushing (FF), apply a small film of fluorocarbon grease on the inside diameter of the bearing and spindle. This will prevent premature wear during initial start-up.

4. Use the following table [Fig. 18] for correct placement of the drive magnet.

Model

ID Mark

H

Figure 18

MXM-221/222

MXM-441

MXM-442

Motor or motor adapter

MXM-542

MXM-543 & 545

Height - H in (mm)

4.69” (119)

4.55” (116)

4.09” (104)

5.98” (152)

6.17” (157)

Mount and bolt the frame (19) to the motor. . (Check orientation/label)

6. Mount and secure the drive magnet (232) to the motor shaft. [Fig. 18] *Note: Use Loctite 242

(thread locker) and torque the set screws to 8.9 ft-lbs (12 Nm).

7. Mount the impeller to the magnet capsule.

The mating part of the magnet capsule has two holes. The larger hole is for the lock pin (stepped hole on the outside is 6 mm dia and the inside is 12mm dia) and a smaller hole (3mm dia.) is for cooling purposes. The U-shaped hole of the impeller and smaller hole (3 mm dia) of magnet capsule are also for cooling purposes. Insert the impeller into the magnet capsule slowly by positioning the two holes together. If it is hard to insert them, warm the magnet capsule only with hot water (176º F 90 deg. C) for five minutes. [Fig. 19]

After the impeller is inserted (press-fit), insert the lock pins from the

Figure 19 inside and then tighten the pin by turning it clockwise 90 degrees from outside with a slotted screwdriver. You will feel a snap when it is fixed securely.

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If the groove for a slotted screwdriver is deformed, the pin can be locked from the inside with a 4mm hex wrench. Turn the wrench counter clockwise. [Fig. 20]

8. Place rear thrust collar (314.1) on shaft (6) and press shaft into rear casing. Make sure the anti-rotational flat on the spindle aligns with the flat edge in rear casing. Place rear casing (231) with spindle (6) and rear thrust collar (231) on pump frame (19).

9. Place assembled impeller (2) and magnet capsule assembly (230) in rear casing (231).

Caution

Magnet force is very strong. Apply plastic or wooden spacers between the rear casing and frame to absorb any slack. [Fig. 21] Be careful not to pinch your fingers.

Figure 21

Figure 20

10 Verify that there are no scratches or foreign material on the sealing surface of the front casing liner (1.3). Install the o-ring (73.1) into the recess in the front casing liner.

Place front casing with liner (1.1 & 1.3) on rear casing (231). Make sure the spindle fits in front casing liner spindle support.

11. Fasten the hex socket bolts (903.1 & 903.2 & 23) in a diagonal order applying equal torque to each.

Required torque is 18.0 ft-lbs. Use a screwdriver to verify that the motor fan rotates smoothly.

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