Watson-Marlow 621CC - Manual (Page 23)

23 620RE, 620RE4 and 620R Tube element or
continuous tube removal
 Unlock the guard and disengage the rollers.

Disconnect the tubing from the external pipeline.

Remove the tubing from the pumphead.
24 620RE, 620RE4 and 620R Maintenance
Scheduled maintenance

The stainless steel pumping rollers run on sealed bearings and do not require
lubrication.

Remove the rotor and lubricate the follower rollers and roller engaging mechanisms
with a lithium-based grease. This should be carried out every six months for
intermittent duties and every three months for 24 hour duties.

If fluid is spilled inside the pumphead, flush the pumphead out with water and mild
detergent as soon as possible. If specific cleaning agents are required to clean the
spillage, please consult Watson-Marlow Technical Support Office before proceeding,
in order to confirm chemical compatibility.

If the rotor needs to be removed, refer to the guidelines below.
Roller adjustment
620 pumpheads have provision for adjustment to reset the roller/track gap to compensate
for wear after extended service in arduous applications.
Roller/track gaps can only be accurately judged without tubing in the pumphead. The gap
should be 5.2mm for 3.2mm wall tubing and 6.2mm for LoadSure elements.
If the gap is more than 0.2mm greater than these dimensions, the following may be carried
out:
 Note the number on the roller arm to which the engraved line on the hexagon-
headed main roller pin corresponds.

Remove the circlip (snap-ring) and roller pin.

Relocate the main roller pin, resetting the engraved line to one number lower. For
example, if the engraved line was at "-1", reset it to "-2" to reduce the roller track
gap.

Ensure the roller pin is correctly seated into the roller arm thrust washer. Replace the
circlip.
Rotor removal and re-location

Remove the rotor cover and central locating bolt using a 5mm Allen key. Pull the
rotor off the keyed shaft, remove the key and clean thoroughly. Do not use tools to
lever the rear face of the rotor away from the inner face of the track, it should come
off by hand.

To replace the rotor, locate the key into the keyway and apply a thin layer of grease
over the shaft and key. Align the keyway of the rotor to the shaft key and slide the
rotor into position, ensuring that a positive "stop" is achieved and ensure that the full
length of the drive shaft is fitted into the rotor.
Page 23 of 46 Watson-Marlow Bredel E-Manuals
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