BUCHI SpeedExtractor E-916 - Manual (Page 81)

8 Troubleshooting
81 SpeedExtractor E-916/E-914 Operation Manual, Version D
8.1.4 The pump is not aspirating properly
NOTE
When the pump is running but the solvent is not aspirated check first if the right solvent port is
selected (see section 6.2.6).
A new pump or a pump that has been out of operation
for a long time may sometimes be difficult to start. The
cause is a dried out solvent on the check valves and
air bubbles stuck on the pumping mechanism. Both
causes result in pressure fluctuations, or solvent intake
fails completely.
• Visually inspect the connections, lines, and filter of
the solvent reservoir. Replace items if necessary as
described in section 6.2.1 and 7.3.1.
• If the pump is still not purging properly, assistance
by means of a syringe is sufficient in most cases.
Slacken the by-pass valve. Turning by 90° counter-
clockwise is sufficient.
• Suck up a solvent using a plastic syringe until the
pump stops producing bubbles. Empty the syringe,
attach it again, start the pump, and watch to see
whether the pump sucks regularly and all bubbles
have been eliminated. Once the pump is working
properly, close the by-pass valve and keep the
pump running for a while.
• If pumping is still irregular, leave the pump running
for approximately 10 minutes and observe whether
the pump pumps regularly and all bubbles have
been eliminated. If the problems persist, repeat
purging (with the by-pass valve slackened).
• If the problem still persists equip the syringe with a
pointed cannula that fits into the intake FEP tube
(ID 1/16”) and fill the syringe with the solvent used
for the extraction method. Press some solvent into
the tube while the pump is running and dip it into
the solvent reservoir as soon as the pump begins
aspirating.
NOTE
The syringe P/N 034882 is made of polypropylene and is therefore not compatible with halogenated
solvents (i.e. dichloromethane) and acids.