Yokogawa GC8000 Process Gas Chromatograph - Manual (Page 387)

<6. Maintenance>
6-34
IM 11B08A01-01E
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 purging air, carrier gas, hydrogen (or nitrogen) gas for
combustion, combustion air, and sample gas.
(4) Open the control unit door using a key included in the accessory kit.
(5) Remove the two couplings connected to the methanizer. When removing the couplings,
label them for ease of identifying the connections later.
(6) Remove the two wires connected to the terminals of the methanizer.
(7) Remove the two screws to remove the methanizer.
(8) Install a new methanizer.
(9) Reconnect the wires and pipes in the reverse order of steps (4) to (7). Confi rm wiring and
perform a leak test.
K9192TG
F0230.ai
Heater terminals
Screw
Screw
Outlet
Inlet
Figure 6.30 Methanizer
(6) Rotary Valve and Valve Seat
The rotary valve located in the isothermal oven is used as a sampling valve and a column
switching valve. The valve has two types: general type and high temp. type. The specifi cations
for the rotary vale used are listed in the parts list in the operation data. Check against the code
chart (Table 6.2) and replace as required.
Table 6.2
Model Suffi x code Option code Description
GCRV •••••••••••••••••••••••••••••••••••••••••••• ••••••••••••••••• Rotary valve
Bellows
material
-G
-M
•••••••••••••••••
•••••••••••••••••
Rubber
Metal
O-Ring
material
B
K
•••••••••••••••••
•••••••••••••••••
Viton
Kalrez
2nd Edition : May 11, 2012-00