Bio-Rad Econo Gradient Pump Kits - Manual (Page 14)

4.0 TUBING SELECTION AND INSTALLATION
4.1 TUBING SELECTION
The Econo Gradient Pump may be used with most flexible tubing
having an inner diameter less than or equal to 3.2 mm (1/8”), and a
wall thickness of 1.0 mm or less, including Silicone, Tygon, and
PharMed. Silicone tubing, the most inert of the three, is suitable for
aqueous and polar solutions. Tygon is suitable for most aqueous
solutions. It will generally have the shortest lifetime of the three and
should not be used for the pumphead. PharMed is the longest lasting
of the three, and will provide the most consistent flow rate over time.
Figure 4-1 shows approximate flow rate ranges with different tubing
sizes. Flow rates above 20 ml/min may be obtained by plumbing two
channels of 3.2 mm tubing through the pump and joining them at the
output.
Very low flow rates can be achieved with tubing having ID as small as
0.51 mm. Tubing this small must be jacketed inside larger tubing and
requires an adapter. These items are included in the optional splitter
valve kit.
Figure 4-1. Approximate Flow Rate Ranges.
Tubing length and the amount of tubing prestretch have a significant
effect on both flow rate calibration and reproducibility of flow. The
PharMed tubing supplied with the Econo Gradient Pump has been
cut to a predetermined length to accommodate tubing prestretch.
(Silicon tubing in precut lengths is also available from Bio-Rad. See
ordering information in Appendix D.)
Tubing Selection
10
TUBING SIZE
(ID x WALL)
FLOW RATE RANGE (ml/min)
0.51 x 0.8 mm
0.8 x 0.8 mm
1.6 x 0.6 mm
3.2 x 0.8 mm
.001 .002 .005 .01 .02 .05 .10 20 .20 .5 1.0 2 5 10
ml/m
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