Alfa Laval Rotary Lobe Displacement Pump GHPD-432

1. Checking the oil level in the gearcase (if applicable).

2. Checking the mechanical seals for leakage and replacing as necessary.

3. Adjusting the packed glands to control leakage.

4. Checking the oil seals for leakage.

CAUTION! DRIP LEAKAGE IS ESSENTIAL TO PREVENT OVER HEATING OF THE GLAND AREA WHICH WILL CAUSE SEAL FAILURE.

IMPORTANT! Stop and remove gland guard for checking temperature of housing and observing leakage. ALWAYS REPLACE THE GUARD BEFORE RESTARTING.

1. Lightly tighten up the gland follower.

2. Flood the pumphead and determine if the gland leakage is acceptable. Tighten the gland follower nuts until an acceptable leakage is achieved.

3. Start the pump and allow to run for 10 minutes. If the gland becomes significantly hotter than other parts of the pump, the gland is too tight.

4. Stop the pump and allow it to cool then repeat the above until the gland temperature is stable and gland slightly weeping.

5. Run the pump at 10 minute intervals tightening the gland follower nuts by a ½ of a turn until the leak is at an acceptable rate.;

CAUTION! COMPLETE DISASSEMBLY IS ONLY REQUIRED IF THE 'O' RINGS OR SPRINGS ARE TO BE REPLACED.

- The relief valve should not be disassembled while the plug is in operation. Always observe the safety precautions detailed at the front of this manual.

- Take extreme care when removing the springs as they have been compressed.

2. Release and remove the notched nuts) with the spring adjuster.

3. Take off the springs, release the socket head cap screws and remove the valve guide.

4. Access to the pneumatic piston 'O' rings is achieved by releasing the circlip which locates in the valve shaft.

5. The hydraulic piston with the shaft may be lifted out of the front cover once the backstop disc is removed.

– The large 'O' ring sits within the rotorcase bore and runs on the shaft sleeve. Rotation for the shaft sleeve is provided by a spring which locates in a slot on the shaft. An 'O' ring seals the shaft sleeve to the shaft.

2. Slide the shaft sleeve from the shaft and inspect the 'O' rings.

1. Lightly lubricate the 'O' rings with greas (food quality if necessary), locate in the shat sleeve and rotorcase bore.

2. Slide the shaft sleeve onto the shaft an locate the pin into the slot on the shaft.;

– The seal rotary face is driven by a pin which locates in a slot on the shaft. A washer is located between the shaft shoulder and rotary face. A seal between the rotary face and shaft is provided by an 'O' ring.

– The stationary face is prevented from rotating as it has a flat side which sits in the rotorcase bore. Face to face contact is provided by a wave spring.

– Axial movement of the stationary face is prevented by a retaining clip. An 'O' ring within the rotorcase bore provides a seal onto the stationary face.

– A seal housing encloses the hyclean seal and is seal by an 'O' ring and retained to the rotorcase by socket head cap screws. A lip seal sits within the seal housing and runs on the rotary face, thus providing a seal.

CAUTION! SEAL FACES ARE BRITTLE - TAKE EXTREME CARE WHEN HANDLING. REMOVING THE FLUSHED HYCLEAN SEAL

REMOVING THE FLUSHED HYCLEAN SEAL

1. Carefully support and remove the rotorcase with the seal housing and stationary face still attached.

2. Slide the rotary face from the shaft.

3. Remove the seal housing screws to inspect the seal.