12.2 520RC, 520R2C and 520REC: good pump installation
practice
General recommendations
The pump may be set up so that the direction of rotor rotation is clockwise or counter-
clockwise, whichever is convenient. Please note, however, that for the 520R and 501RL
pumpheads tube life will be greater if the rotor rotates clockwise; and that performance
against pressure will be maximised if the rotor rotates counter-clockwise. To achieve 4 bar
and 7 bar pressures using a 520RE pump and the appropriate rotor and element, the pump
must
rotate counter-clockwise.
Peristaltic pumps are self-priming and self-sealing against backflow. No valves are required
in inlet or discharge lines, except as described below. Valves in the process flow must be
opened before the pump operates. Users are advised to fit a pressure relief device between
the pump and any valve on the discharge side of the pump to protect against damage
caused by accidental operation with the discharge valve closed. Users of 520RE pumps at
pressures up to 4 bar and 7 bar are advised to fit a non-return valve between the pump and
the discharge pipework to avoid the sudden release of pressurised fluid in the unlikely event
of element failure.
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. Any valves in the pipeline (not usually needed with a self-
priming peristaltic pump) must not restrict the flow.
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
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 rollers clean and free from debris.
When using Marprene or Bioprene tubing
, re-tension the tube after the first 30 minutes
of running.
Tube selection
: The chemical compatibility list published in the Watson-Marlow catalogue
is only a guide. If in doubt about the compatibility of a tube material and the duty fluid,
request a Watson-Marlow tube sample card for immersion trials.
A correctly engineered installation will promote long tube life. Please ensure that these
guidelines are followed:
Avoid tight pipeline bends, pipe reducers and lengths of smaller bore tubing than the
pumphead section, particularly in pipelines on the suction side.
Ensure that at least 1m of smooth bore flexible tubing is connected to the discharge port
of the pumphead to help to minimise impulse losses and pulsation in the pipeline. This is
specially important with viscous fluids and when connecting to rigid pipework.
Ensure that connecting pipework and fittings are suitably rated to handle the predicted
pipeline pressure. If rigid pipework must be used close to the pumphead, a drop-out
section of pipe will simplify tube replacement.
Page 20 of 47
Watson-Marlow Bredel E-Manuals
14/12/2009
file://M:\staging\pdfs-global\m-521-cc-gb-03.htm
