Yokogawa GC8000 Process Gas Chromatograph - Manual (Page 376)

<6. Maintenance>
6-23
IM 11B08A01-01E
(2) Regulator for Utility Gases
These regulators are installed in the upper front side of the isothermal oven for the respective
oven unit and used to control the pressures of the FID hydrogen (or nitrogen) for combustion and
FID combustion air (see Figure 6.20).
(1) Stop the operation. (See “3.3.4 Stopping operation” for this procedure).
(2) Stop the supply of power.
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.
(3) Turn off the supplies of the FID hydrogen (or nitrogen) gas for combustion, FID combustion
air, and carrier gas.
(4) Open the door of the isothermal oven section in the oven unit as well as the door above it.
(5) Remove the front panel of the regulator by loosening the two screws.
(6) Remove the couplings connected to the inlet (IN) and outlet (OUT) of the regulator. See
Figure 6.18. Label the couplings with “IN” and “OUT” for ease of identifi cation later.
Note
Remove any metal fl akes off the couplings.
(7) Remove the stem lock.
(8) Remove the mounting locknut.
(9) Remove the upper two screws and loosen the lower two screws of the board on which the
gauge and regulator are mounted.
(10) Slide the board to remove the regulator.
(11) Install a new regulator in the reverse order of steps (6) to (10).
(12) Reinstall the front panel of the regulator in its original position.
(13) Start supplying the FID hydrogen (or nitrogen) gas for combustion, FID combustion air and
carrier gas, then perform a leak test around the couplings.
(14) Set the pressure of the line where the regulator has been replaced to the value indicated in
the operation data (attached).
Adjust and set the pressure by loosening the stem lock and rotating the stem.
After completing the setting, fi x the stem with the locknut.
(15) Close the door of the isothermal oven for the oven unit.
IMPORTANT
After the temperature of the isothermal oven in the oven unit becomes substantially stable, set
the pressure of the carrier gas again according to the Operation data.
<Replacement Parts>
K9409AW
2nd Edition : May 11, 2012-00
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