Watson-Marlow 621CC - Manual (Page 6)

6 Do's and do not's
Do not build a pump into a tight location without adequate airflow around the pump.
Do not strap the control and mains power cables together.
Do keep delivery and suction tubes as short and direct as possible - though ideally not
shorter than 1m - and follow the straightest route. Use bends of large radius: at least four
times the tubing diameter. Ensure that connecting pipework and fittings are suitably rated
to handle the predicted pipeline pressure. Avoid pipe reducers and lengths of smaller bore
tubing than the pumphead section, particularly in pipelines on the suction side. Any valves
in the pipeline (not usually needed) must not restrict the flow. Any valves in the flow line
must be open when the pump is running.
Do use suction and delivery pipes equal to or larger than the bore of the tube in the
pumphead. When pumping viscous fluids use pipe runs with a bore several times larger
than the pump tube.
Do ensure that on longer tube runs at least 1m of smooth bore flexible tubing is connected
to the inlet and discharge port of the pumphead to help to minimize impulse losses and
pulsation in the pipeline. This is especially important with viscous fluids and when
connecting to rigid pipework.
Do site the pump at or just below the level of the fluid to be pumped if possible. This will
ensure flooded suction and maximum pumping efficiency.
Do keep the pumphead track and all moving parts clean and free from contamination and
debris.
Do run at slow speed when pumping viscous fluids. Flooded suction will enhance pumping
performance in all cases, particularly for materials of a viscous nature.
When using Marprene or Bioprene continuous tubing, do re-tension the tube after the
first 30 minutes of running.
Tube selection: The chemical compatibility lists published in Watson-Marlow publications
are guides. If in doubt about the compatibility of a tube material and the duty fluid, request
a Watson-Marlow tube sample card for immersion trials.
Page 6 of 46 Watson-Marlow Bredel E-Manuals
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