Hach 900 MAX - Manual (Page 100)

Page 98
Upgrades, Repairs, General Maintenance
8990mnt.fm
Section 7
Note: To extend the life of the
tubing, rotate the pump tube 90
degrees in the pump housing after
approximately
2 / 3 of the life has
been realized (once the tube life has
been determined through use).
Experience at a particular site will be your best indicator of tubing life. Visually
inspect the tubing and rollers on a regular basis after initial installation to get a
feel for what maintenance your site will require. Be sure to replace the pump
tubing before it splits to prolong the life of the sampler and keep the work area
free of contamination from the sample liquid.
The proper length of silicone tubing must be used in the pump body. An
improper length can reduce the life of the tubing and pump rollers. Refer to
Figure 29 for the correct length.
Figure 29 Pump Tube Loading
7.2.2 Replacing Pump Tubing
1. To replace the pump tube, remove the four screws on the pump cover.
2. Remove the front cover of the pump housing.
3. Remove the existing tubing. Locate the black dot on the new tubing. The
end of the tube that extends farthest beyond the black dot attaches to the
stainless steel tubing connector.
4. Install the pump tube in the pump housing until the black dots are visible
just outside the pump body.
5. After inserting the new pump tube, reinstall the front cover and secure it
with the four screws until finger tight.
7.3 Upgrades, Repairs, General Maintenance
Only a qualified technician should service the sampler. For example, steps
that require knowledge of CMOS electrostatic discharge precautions and
advanced electronics training and should only be performed by a qualified
technician. If you need assistance in performing any of the following service
steps, contact the manufacturer.
To Intake Tubing Connector
5 3/4 in. to Sample Fitting
11 5/8 in.
(Tubing in Pump)