Watson-Marlow 520Du - Manual (Page 86)

Watson-Marlow 520DuN IP66/NEMA 4X User Manual 86
Mark a 225mm (8 7 ⁄
8
in) length onto the section of the tubing which is to be
located into the pumphead. Caution: Placing more than 225mm (8 7 ⁄
8
in) of
tube inside the pumphead may result in reduced tube life.
Open the lower spring-loaded tube clamp and locate the tubing, with the first
225mm (8
7 ⁄
8
in) length mark aligned to the inside face of the spring-loaded
part of the tube clamp. Release the clamp.
Disengage the rotor clutch by fully depressing the yellow clutch button on the
side of the rotor hub and turning the hub a few degrees while the clutch button
is still depressed. The rotor can now rotate independently of the gearbox and
motor for one full revolution. If the clutch re-engages before tube fitting is
complete, depress the clutch button again and turn the rotor a few degrees.
Feed the tubing around the pumphead track, turning the rotor as necessary.
Make sure the tubing is not twisted or pinched between the guide rollers and
the track. Ensure that the second 225mm (8
7 ⁄
8
in) mark is adjacent to the
inner edge of the upper tube clamp.
Open the upper spring-loaded tube clamp and locate the tubing into it, making
sure there is no residual twist in the tubing, and that the tube sits centrally
between the tube guide rollers. Release the clamp.
The spring-loaded tube clamps must grip the tubing tightly enough to stop it
moving in and out of the pumphead but must not over-squeeze the tube and
throttle fluid flow. The tubing clamps are fitted with yellow sliders which can be
clicked into two positions while the clamps are held open: the outer position
will allow the clamps to grip the tube tightly; the inner will grip the tube loose-
ly. Adjust the sliders to prevent tube movement during a few trial rotations of
the rotor.
Close the guard, pushing it fully home until the latch engages.
Connect suitable pipework to the pumphead tubing using appropriate connec-
tors.
Remember, when using Marprene or Bioprene tubing, re-tension the tubing
after 30 minutes of running, as it may grow in length as it beds in. Re-tension
so that 225mm (8
7 ⁄
8
in) of tubing sits between the inside faces of the spring-
loaded parts of the tube clamps.