Watson-Marlow 501RL - Manual (Page 6)

Part 1 : 501RL pumphead
Description
The 501RL pumphead has two spring-loaded rollers, which automatically
compensate for minor variations in tubing wall thickness, giving extended
tube life.
The 501RL is set during manufacture to accept tubing with wall thicknesses
of between 1.6mm and 2.0mm, and internal diameters of up to 8.0mm. The
501RL pumphead is equipped with a "tool lockable" guard for increased
safety, this should be locked shut whilst the pump is in use.
A major feature of the 501RL pumphead is the ability to run the pumphead
clockwise for extended tube life, or anti-clockwise to operate against higher
pressures.
The tube clamps of the 501RL are adjustable to four positions to allow varying
tube diameters to be securely held without occluding the tube.
Installation
Any one of three tubing input/output positions can be selected on cased
drives. Select the required position then fit the track over the drive shaft and
locating boss. Tighten the track retaining screw.
After checking that the shaft is clean and degreased slide the rotor on to it. Fit
the track in any one of three orientations, over the drive and locating boss.
Secure the track with the locating screw. Ensure the drive shaft is degreased
before locating the rotor onto the shaft via the split collet. Rotate rotor until
its guide rollers are alligned flush to the front edge of the track. Tighten
the rotor screw to a torque of 3Nm to prevent the collet slipping during
operation.
To reposition the track, remove any tubing from the pumphead, and swing out
the crank handle to expose the rotor retaining screw. Turn the screw
anticlockwise one turn to release the collet, and withdraw the rotor from the
shaft. Loosen the track locating screw, and pull the track clear. Rotate the
track to its new position and tighten the track locating screw.
Roller adjustment
The 501RL has a factory set gap of 2.6mm between the rollers and the track
and is suitable for tubing having wall thicknesses of between 1.6 and 2.0mm.
Adjustment of the gap will be required if tubing having a wall thickness of less
than 1.6mm is required. There is an adjusting screw on each of the two roller
arms, and each of these screws will require adjustment. The correct gap is
twice the wall thickness less twenty percent. Correct adjustment is important:
over occlusion will reduce tube life; under occlusion will reduce pumping
efficiency.
To change the gap setting, turn each adjusting screw clockwise to increase
the gap, or anticlockwise to decrease the gap. A full turn changes the gap by
0.8mm.
To restore the original settings of 2.6mm, turn the adjusting screws until both
rollers are just touching the track, then tighten each screw by three and a
quarter turns.
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