Pentair MPRA, MPEA Pump Dissasembly/Removing Old Seal, Pump Reassembly/Installing New Seal

If shaft seal is worn or damaged, repair as follows:

Pump Dissasembly/Removing Old Seal

Disconnect power to pump motor.

Be sure valves on suction and return piping are closed before starting work.

Pump Reassembly/Installing New Seal

1.Ceramic seat must be clean and free of dirt, grease, dust, etc. Wet outer edge with small amount of liquid detergent; press ceramic seat into seal plate cavity firmly and squarely with finger pressure (Figure 7).

Release all pressure by opening all vents before starting work.

1.	Drain pump by removing drain plugs on bottom of
	pump body and trap body.
2.	Be sure there is no pressure in trap body; remove
	cover (unscrew by turning counterclockwise).
3.	Remove 6 nuts, lockwashers and flat washers holding
	seal plate to pump body. Pull seal plate and motor
	away from pump body. (You may have to CAREFULLY
	use a screwdriver to separate body from seal plate.)
4.	Remove seven screws and washers holding diffuser to

Polished surface

Figure 7

Rubber surface

	seal plate. Remove diffuser.
5.	Remove motor canopy. Being careful not to touch ca-
	pacitor terminals, loosen capacitor clamp and move
	capacitor to one side.
6.	Hold shaft with 7/16" open-end wrench on motor
	shaft flats.
7.	Unscrew impeller from shaft (turn counterclockwise
	when facing it).
	NOTICE: On 2 HP model, remove impeller screw
	(left hand thread - turn clockwise) and gasket before
	removing impeller. Inspect gasket for damage,
	cracks, etc. Replace if damaged.
8.	Remove four screws holding seal plate to motor.
9.	Place seal plate face down on flat surface and tap out
	ceramic seat (Figure 6).
10.	Remove slinger from motor shaft and inspect for dam-
	age or abrasion.
11.	Clean seal cavity in seal plate and clean motor shaft.

Mechanical seal ceramic seat

Figure 6

2.If ceramic seat will not locate properly, remove it, place face up on bench and reclean cavity. Ceramic seat should now locate.

3.If seat still will not locate properly, place a cardboard washer over the polished face and use a piece of 3/4" (19mm) standard pipe for pressing purposes.

NOTICE: Be sure not to scratch or mar polished sur- face or seal will leak.

4.Replace slinger on end of motor shaft so that impeller sleeve will push it into position. If slinger shows signs of wear or damage, replace it.

5.Remount seal plate on motor. Tighten bolts to 60-80 inch-lbs. (69-92 kg/cm) torque.

6.Apply a small amount of liquid detergent to inside di- ameter of rotating half of seal.

7.Slide rotating seal member, polished carbon face out, over impeller sleeve until rubber drive ring hits back of impeller.

NOTICE: Be sure not to nick or scratch polished seal face; seal will leak if face is damaged.

8.Screw impeller onto shaft (clockwise); this will auto- matically locate seal in seal plate.

NOTICE: On 2 and 2-1/2 HP models; install impeller gasket and lock screw (left-hand thread - turn coun- terclockwise). Torque lock screw to 50-55 inch-lbs. (57.6-63 kg/cm).

9.Mount diffuser on seal plate; tighten screws to 10-14 inch-lbs. (11.2-16.1 kg/cm) torque.

10.Assemble motor and seal plate to pump body with nuts, flat washers and lock washers. Torque nuts to 120-130 in-lbs. (138-150 kg/cm).

11.Prime pump according to instructions on Page 9.

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