18 Maintenance and Inspection
18.4 Inspection and Maintenance: O-ring for glass insert
292
GC-2010 Plus
Q Leak check
A leak will affect reproduceability and carrier gas will be wasted.
Confirm whether there is a leak or not according to the following procedure:
(As for the following procedure, there could be cases in which the error message “purge
leaks” etc. appears. However, it does not matter to the test. Then, select “Reset Error”.)
(1) Set the “Flow Control” to “Cont” on the screen after pressing [SYSTEM] key.
(2) Push the [Stop GC] (PF menu), and the system stops.
(3) Wait that all oven temperature, injection port temperature and detector temperature is
below 40 degrees on the screen after pressing the [MONIT] key.
(4) Push the [On/Off] (PF menu) on the screen after pressing the [FLOW] key, and the
control of AFC stops.
Set the purge flow rate to “0 ml/min".
(5) Remove the capillary column, and blank off with a column nut and the graphite ferrules
with a wire.
(6) Install the blind (G-type blank nut) to the split vent and purge vent port.
(7) Make sure that the supply pressure to the carrier gas (the pressure from a gas cylinder)
is above 300 kPa.
(8) Set the “Split mode” to “DIRECT” and “Control mode” to “PRESS” on the screen of the
after pressing the [FLOW] key.
(9) Set the inlet pressure to 150 kPa. Push the [On/Off] (PF menu), and the control of AFC
starts.
(10) Wait for five minutes. Confirm that the inlet pressure is 125 ~ 175 kPa. If the inlet
pressure is above 175 kPa, unfasten the column a little nut and set the pressure free.
If the inlet pressure is below 125 kPa, raise the supply pressure a little.
(11) Confirm that the total flow is below 2 ml/min. If the total flow is above 2 ml/min, then
there is a leak somewhere.
(12) Push the [On/Off] (PF menu) on the screen of the [FLOW] key, and the control of AFC
starts.
(13) In case of fluoride rubber O-ring, confirm that the pressure does not drop more than 15
kPa per hour or 2.5 kPa in 10 minutes.
In case of graphite O-ring, confirm that the pressure does not drop more than 21 kPa
per hour or 3.5 kPa in 10 minutes.
If the pressure has dropped more than the above specified values, there is a leak
somewhere.
(14) When the leak check has passed set the system back into operating status.
Q Possible leak positions
In case the leak check conditions has failed check the following items on the GC for possible
leaks:
septum injection inlet, around the injection port, the connection of piping, split vent (around
the blind plug), purge vent (around the blind plug) and the connection of column with a leak
detector or snoop.
In case you have localized a leak in one of the above positions do the following according to
the leak localization:
• Septum injection inlet : replace septum.
• Around the injection port : replace O-ring of glass insert.
• Split vent : replace blind plug seal.
• Purge bent : replace blind plug seal.
• Connection of column : replace graphite ferrules and column nut.
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