moyno 331, 344, 333, 332, 500 Service Manual

Section:

MOYNO®500 PUMPS

Page: 1 of 4
Date: March 2002

SERVICE MANUAL

MOYNO®500 PUMPS

SANITARY/HYGIENIC MOTORIZED

331, 332, 333 AND 344 MODELS

SANITARY MODELS

These pumps include housings polished to a #4 finish
both inside and out.The Durametallic FRO mechanical seal
has carbon/ceramic faces. The elastomers meet the FDA
requirement for food contact.These pumps meet 3A require­ments.The universal joint may be dismantled for cleaning.

HYGIENIC MODELS

These pumps provide the quick disassembly features
of the sanitary version for easy cleaning. The housings
are 316 stainless steel construction, however they are
not polished. These pumps utilize rubber-covered
universal joints. The stators are available in non-FDA
nitrile, EPDM and fluoroelastomers. The mechanical seals
are rubber bellows type with carbon/ceramic faces.

INSTALLATION

Mounting Position. Pump may be mounted in any posi-

tion. When mounting vertically, it is necessary to keep the
motor above the pump to prevent possible seal leakage into
the bearings.

Pre-Wetting. Prior to connecting the pump, wet the pump
elements and mechanical seal by adding fluid to be
pumped into suction and discharge ports. Turn the pump
over several times in a clockwise direction to work fluid
into the pump elements.

Piping. Piping to the pump should be self-suppor ting to
avoid excessive strain on pump housings.

Electrical. Follow the wiring diagram on the motor name­plate or inside the terminal box for the proper connections.
The wiring should be direct and conform to local electrical
codes.Check power connections f or proper v oltage . Voltage
variations must not exceed

+

10% of nameplate
voltage.The motor is provided with internal automatic over­load protection.

To prevent damage to the pump, pump rotation must be

clockwise when facing the pump from the motor end.

OPERATION

Self-Priming. With wetted pumping elements, the pump

is capable of 25 feet of suction lift with pipe size equal to

port size. Be sure suction lines are air tight or the pump
will not self prime. Self-priming capabilities will vary due to
fluid viscosity.

DO NOT RUN DRY. The unit depends on liquid pumped
for lubrication.For proper lubrication, the flow rate should be
at least 10% of rated capacity.

Pressure and Temperature Limits. See Table 1 for max­imum discharge pressure of each model.The unit is suitable
for service at temperatures shown in Table 2.

Storage. Always drain the pump for extended storage
periods by removing the suction housing and stator.

Caution: Suction pressure should never be greater

than discharge pressure.

Table 1. Pump Data

Table 2.Temperature Limits

*FDA Food Grade on Sanitary Models. FDA Fluoroelastomer
not currently available. Call factory.

Pump Models
Discharge

Pressure
(psig) (maximum)

331 332 333 344

150 100 50 40

Elastomer Temperature Limits

*NBR (Nitrile) 10˚-160˚F

*EPDM 10˚-210˚F

FPM (Fluoroelastomer) 10˚-240˚F

TROUBLESHOOTING

WARNING: Before making adjustments, disconnect

power source and thoroughly bleed pres­sure from system prior to disassembly.
Failure to do so could lead to electric
shock or serious bodily harm.

Failure T o Pump.

1. Motor will not star t: Check the power supply. Voltage

must be

+

10% of nameplate rating when the motor
is in locked rotor condition. Check for faulty capacitor on
1-phase models.

2.Motor runs and thermally kicks out:Check for excessiv e
discharge pressure. Check for defective centrifugal switch
on 1-phase models. Increase ventilation to motor. Do not
use less than #14 wire size.

3. Stator torn; possible excessive pressure: Replace
stator; check pressure at discharge port.

4. Flexible joint broken; possible excessive pressure:
Replace joint, check pressure at the discharge port.

5.Wrong rotation (3-phase only): Rotation must be clock­wise when facing pump from motor end. Reverse the con­nections of any two line leads to the motor.

6. Excessive suction lift or vacuum.

Pump Overloads.

1. Excessive discharge pressure: Check pressure at
discharge port for maximum ratings given in Table 1.

2. Fluid viscosity too high: Limit fluid viscosity to 100 CP
or 500 SSU.

Noisy Operation.

1. Excessive suction lift or vacuum: Maximum suction
lift is 25 feet for water.

2. Suction line too small: Check pipe size. Be sure lines
are free from obstructions.

3. Pump cavitates: Pump speed is 1725 rpm. Viscosity
of fluid should not exceed 100 CP or 500 SSU.

4.Flexible joint worn:Replace joint. Check pressure at the
discharge port.

5. Insufficient mounting: Mount securely to a firm
base. Vibration induced noise can be reduced by using
mount pads.

Seal Leakage.

1. Leakage at startup: If leakage is slight, allow pump to
run several hours to let faces run in.

2. Persistent seal leakage: Faces may be cracked from
freezing or thermal shock. Replace the seal.

Pump Will Not Prime.

1. Air leak on suction side: Check pipe connections.

PUMP DISASSEMBLY

WARNING: Before disassembling pump, disconnect

power source and thoroughly bleed
pressure from system. Failure to do so
could result in electric shock or serious
bodily harm.

1. Remove suction and discharge piping.

2.Remove clamp (112) holding suction housing (2) to dis-

charge housing (1).Remove suction housing (2) and stator (21).

3. Remove rotor (22) from flexible joint (24) by turning

counterclockwise (RH thread).

4. Flexible joint (24) can be removed from motor shaft
by using a 3/16 Allen wrench in end of joint and turning
counterclockwise. Sanitary joints can be further dis­assembled by removing the snap rings, allowing the pins
to be removed.

5. Slide mechanical seal (69) off motor shaft.

6.Remove discharge housing (1) from adapter flange (12)
by removing screws (112B).

7. Carefully pry seal out of discharge housing (1). If any
parts of mechanical seal are worn or broken, the complete
seal assembly should be replaced. Seal components are
matched parts and are not interchangeable.

8. Remove adapter flange (12) from motor (70) by remov­ing screws (112A).

9. Remove slinger ring (77).

PUMP ASSEMBLY

1. Install slinger ring (77).

2. Attach adapter flange (12) to motor housing using
screws (112A).

3. Attach discharge housing (1) to adapter flange (12)
using screws (112B). Be sure to center seal bore on shaft.

4. Install mechanical seal (69) in discharge housing (1)
using the following procedure:

a. Clean and lubricate sealing faces using clean

vegetable oil (not grease).

Caution: Do not use oil on EPDM parts. Substitute

glycerin,soap and water, or approved lubricate.

b. Lubr icate outer surfaces of the seal seat, and push
assembly over the motor shaft and into the discharge
housing (1) seating it firmly and squarely.

c. After cleaning and lubricating the shaft, slide the

seal body along the motor shaft until it meets the seal seat.

d. Install seal spring and spr ing retainer on shaft.

5. Assemble sanitary joint by sliding center section
between two ends. Insert pins and retain with snap rings.
Thread flexible joint (24) into motor shaft in a clockwise
direction (RH thread).Tighten with 3/16 Allen wrench.

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