Hach EZ Serie Manuel De L'utilisateur page 18

5.4 Plumbing
5.4.1 Sample line guidelines
Fire hazard. This product is not designed for use with flammable samples.
Select a good, representative sampling point for the best instrument performance. The sample must
be representative of the entire system.
• Make sure that the sample flow is higher than the flow to the analyzer.
• Make sure that the sample line is at atmospheric pressure if the analyzer uses a peristaltic pump
to move the sample into the analysis vessel.
• Make sure that the sample line collects sample from a small overflow vessel near to the analyzer.
The sample in the overflow vessel must be continuously refreshed. If the size of solids in the sample
is too high, sample filtration is also recommended.
5.4.2 Drain line guidelines
Fire hazard. The user is responsible to make sure that sufficient precautions are taken
when the equipment is used with methods that use flammable liquids. Make sure to obey
correct user precautions and safety protocols. This includes, but is not limited to, spill
and leak controls, proper ventilation, no unattended use, and that the instrument is never
left unattended while power is applied.
Chemical exposure hazard. Dispose of chemicals and wastes in accordance with local,
regional and national regulations.
Do not connect the drain lines to other lines because backpressure or damage to the analyzer can
occur. Make sure that the drain lines are open to air.
To prevent backpressure and damage to the analyzer, make sure that the analyzer is higher than
the facility drain(s) used and that the drain line has a constant downward slope. Install the drain
lines with a 2.54 cm (1 inch) or more vertical decrease for each 0.3 m (1 ft) length of tubing.
The analyzer uses the drain line to release the sample and reagents after analysis. Correct
installation of the drain lines is important to make sure that all of the liquid is removed from the
instrument. Incorrect installation can cause liquid to go back into the instrument and cause damage.
A floor or sink drain is sufficient for the drain line. The recommended external diameter for the drain
tube is 32 mm.
• Make the drain lines as short as possible.
• Make sure that the drain is lower than the analyzer.
• Make sure that the drain lines have a constant slope down.
• Make sure that the drain lines do not have sharp bends and are not pinched.
• Make sure that the drain lines are open to air and are at zero pressure.
• Make sure that the drain lines are closed to the ambient of the installation room.
• Do not block or submerge the drain line.
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