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Product Service: Domestic 1-800-522-7658, International 816-333-8811
Chapter 7: Troubleshooting
PROBLEM
CAUSE
CORRECTIVE ACTION
Poor vacuum (greater
than 500 x 10
-3
mBar)
(cont.)
Leaks in vacuum lines or
connections
Locate and repair
Foreign material on lid
gasket
Clean gasket and lid
Damaged sample valve
Locate and replace
Vacuum Leak Detection
The Freeze Dryer should achieve a vacuum of 133 x
10
-3
mBar within 10 minutes and should achieve an
ultimate vacuum of 33 x 10
-3
mBar within 18 hours.
This extended time interval may be necessary to allow
all the components in the system to outgas. After
components have outgassed, the pull down time will
decrease. To achieve sufficient vacuum, all joints and
connections must be tight, the vacuum pump must be
operating properly, and the collector temperature must
be –40°C or lower. If your Freeze Dryer does not
obtain a satisfactory vacuum, the following procedure
should be used to locate and correct any vacuum
problems.
1. Check each sample valve on the drying chamber or
manifold and look for visible damage and for proper
installation. To isolate a suspect valve, remove the
valve and insert a rubber plug in its place. If the
valve proves to be leaking, the plug can be left in
place so the drying chamber/manifold can be used
until a replacement valve can be obtained.
2. Check vacuum pump oil sight glass. Replace the oil
if it is dirty or cloudy; add oil to the pump if the
level is low. Close the pump gas ballast valve.
Refer to the vacuum pump manufacturer’s
instructions for further information.
3. Check the collector chamber lid gasket for
indentations, cracks or tears. Also clean the gasket
using a soft, lint free cloth or paper towel.
4. Check all vacuum hoses and lines for cracks.
