Agilent Technologies 8453 User Manual, Installing And Operating Manual page 89

Some earlier models of the valve drive assembly turn continuously when the valve is not
N O T E
fitted. Place and hold a screwdriver in the slot on the rotor drive to provide mechanical
resistance. Do not turn the screwdriver.
Leaking Tubing Connectors at Valve
This may be solvent leaks or air leaks causing bubbles in the tubing.
1 Check the connectors at the valve are tightened fully.
2 Check the connectors at the valve are not damaged. If the connectors are
Leaking Valve
Solvent is leaking and you can see solvent at the recess on the underside of the
valve, or air is being drawn in and also causing air bubbles in the valve tubing.
1 Check there is no restriction before the valve causing reduced pressure in
2 If there is no flow in all eight inlet tubings, either the outlet tubing is
3 If there is no flow in some of the inlet tubings, either these tubings are
4 To check if a tubing is blocked, connect the tubing directly to the pump and
Agilent 8453 Dissolution Testing System Installing and Operating Manual
If the valve drive assembly does not operate, call Agilent Technologies.
If the valve drive assembly operates, the valve has stuck. Clean the valve,
see "Cleaning Tubing and Valve"
damaged replace them, see
the tubings.
blocked (see step 4) or the valve is blocked and needs cleaning, see
"Cleaning Tubing and Valve"
blocked (see step 4) or the valve is blocked at these positions and needs
cleaning, see "Cleaning Tubing and Valve"
observe the liquid meniscus while pumping solvent. If the tubing is blocked,
replace it.
Using the Valve Unit and Valve-pump Controller
Troubleshooting Your Valve System
on page 91.
"Replacing Fittings"
on page 91.
on page 91.
on page 94.
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