Yokogawa GC8000 Process Gas Chromatograph - Manual (Page 408)

<6. Maintenance>
6-55
IM 11B08A01-01E
• When the stream switching valve is a pneumatic valve, change the analyzer status to
Manual and turn on the stream switching valve on the sample line to let the purge gas fl ow
in.
• When the stream switching valve is a stop valve, close all the stop valves and open the stop
valve on the sample line to let the purge gas fl ow in.
(4) Close all the stream switching valves.
IMPORTANT
• During the purge, purge gas may fl ow into the sample return line, causing pressure
fl uctuation.
Prepare the sample return line and collection tank, if necessary.
• Prepare the sample return line so that the sample does not return.
CAUTION
The isothermal oven is extremely hot after turning off the power immediately. Keep the purging
air supplied for more than an hour after turning off the power. Keep hands away from the oven
components.
(5) Remove the lower pipe connected to the fl owmeter assembly.
(6) Hold the connector and loosen nut 1 and nut 2.
(7) Gently move the connector downward and remove the taper tube. Replace the gasket if any
damage is found.
(8) Install a new taper tube in the reverse order of steps (5) to (7).
(9) Confi rm that there are no leaks in the piping.
L9866AK Taper tube (for gas sample, 1.1 l/min)
L9866AP Taper tube (for gas sample, 150 ml/min)
L9866AR Taper tube (for liquid sample, 100 ml/min)
L9866AS Taper tube (for liquid sample, 20 ml/min)
K9193GQ Gasket (for gas sample, Viton)
K9193GR Gasket (for liquid sample, Tefl on)
K9805ZA Gasket (for liquid sample, Daiel Par-fl our)
(4) Pressure Gauge
See Figure 6.48 for the replacement procedure.
(1) Stop the operation. (See “3.3.4 Stopping operation” for this procedure).
(2) Turn off the supply of the sample.
(3) If the sample is liquid, purge the sample line with the purge gas (nitrogen gas or instrument
air).
• When the stream switching valve is a pneumatic valve, change the analyzer status to
Manual and turn on the stream switching valve on the sample line to let the purge gas fl ow
in.
• When the stream switching valve is a stop valve, close all the stop valves and open the stop
valve on the sample line to let the purge gas fl ow in.
2nd Edition : May 11, 2012-00
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