Metrohm 772 Pump Unit - Manual (Page 25)

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5 Operation and maintenance
772 Pump Unit
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5.2.2 Suitability test for tubing materials
Place a piece of the tubing in question for 48 hours in a closed container
filled with the liquid in question. Then examine the piece of tubing for
signs of swelling, embrittlement or other damage.
5.2.3 Tubing dimensions
Note
Use tubing with a wall thickness of 1.6 mm only.
The largest usable inner diameter is 6.4 mm.
5.2.4 Tubing lifetime
The pump tubing has a limited lifetime and therefore has to be replaced
regularly. The following are examples of factors that can influence the life-
time of tubing in peristaltic pumps:
￭ Chemical resistance of the pump tubing
￭ Pump rate (rotational speed)
￭ Properties of the pumped liquid
￭ Outlet pressure
￭ Ambient temperature
￭ Shearing force of the rollers
￭ Twisted or kinked tubing
￭ Tubing too long
￭ Wall thickness of 1.6 mm not complied with