Watson Marlow Pumps 604U, Manual

9

Tube loading 

Isolate drive from the mains supply. If the pump is not switched off before the pumphead guard 
is raised, a switch on the guard will cut off power to the motor. This switched guard is a safety 
back-up system and must not be used as the primary on/off switch for the pump.

 
Open the pumphead guard and fit one end of the tube into the bottom adjustable clamp. Tighten the lower serrated 
adjustment wheel. Whilst rotating the rotor clockwise (a spanner is provided for this purpose), feed the tube between 
the rollers and the track, aligning it with the rotor tube guides. The tubing must lie naturally against the track and must 
not be twisted or stretched.  

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Pump shown in tube loading pictures is the 603S/R

Fit the other end of the tube into the top adjustable clamp, ensuring that the tube is not slack in the pumphead since 
this can reduce tube life. Clamp the tube very firmly by turning the upper serrated adjustment wheel. Remove the 
spanner and close the guard. 

Roller adjustment 

Should it ever appear that the roller arms are not equally adjusted, the original factory setting of 5.2mm can easily be 
restored. Turn the adjustment screws on each roller arm anticlockwise until both rollers are just in contact with the 
track, and then turn each screw clockwise by five turns. Correct adjustment is important. For 4mm wall thickness 
tubing turn the screw clockwise by six and a half turns giving a roller/track clearance of 6.6mm. 

Over-occlusion will reduce tube life. Under-occlusion will reduce pumping efficiency. 

Check moving parts of the rotor from time to time for freedom of movement. Lubricate pivot points and rollers 
occasionally with a light machine oil. For scheduled maintenance, remove the rotor from the pumphead, clean 
thoroughly and apply Teflon lubricating oil to the roller spindles.