Watson-Marlow 120U/D1 - Manual (Page 33)

Watson-Marlow 400D1, 400DM2 and 400DM3 pumpheads: operating instructions 5
3.8 400D1, 400DM2
and 400DM3
performance
Tube life and performance against
pressure
The pressure and the suction height can be
increased by compressing the spring in the sprung
track pin. A smaller gap between the rollers and
track will give better performance against pressure
but will reduce tube life.
Other application factors that will influence tube life
in peristaltic pumps are pump speed and number of
rollers (roller impacts/minute), temperature,
chemical compatibility of the duty fluid and viscosi-
ty of the duty fluid. Several tubing materials are
available offering different levels of life expectancy.
The tubing’s dimensional tolerances from the
manufacturing process will also influence the life of
a tube.
This means that it is impossible to predict tube life
in any particular application.
In perfect conditions of no suction or discharge
pressure, in a clean environment at normal room
temperature, and pumping water, nominal tube life
may be:
Marprene and Bioprene: less than 6,000 hours
Silicone: less than 250 hours
Others: less than 100 hours
The factors highlighted above will tend to reduce
tube life. For precise and repeatable
performance it is important to determine flow
rates under operating conditions for each new
piece of tubing.
Note: Flow rates quoted have been rounded for
simplicity, but are accurate to within 5%—well
within the normal tubing tolerance variation of flow
rate. They should therefore be taken as a guide.
Real flow rates in any application must be deter-
mined empirically.
400D1 Pumpsil (ml/min)
Speed range 0.5mm 0.8mm 1.6mm 2.4mm 3.2mm 4.0mm
120U
0.1-200 rpm 0.001-2.2 0.003-5.8 0.011-23 0.02-49 0.041-81 0.06-120
120S
1-200 rpm 0.01-2.2 0.03-5.8 0.11-23 0.24-49 0.41-81 0.59-120
Note: The 120S and the 120U must be run counter-
clockwise to achieve pressures up to 2 bar.