Agilent Technologies 6850 Series II Instruction Manual

Installing the CO2Cryogenic
Agilent 6850 Series II Network GC System
Accessory G2625B
Oven Cooling Kit
This kit contains:
The kit is factory-assembled. Do not disassemble it during installation. The
GC must have firmware revision A.03.00 or higher.
Description Quantity
Chassis 1
Chassis Cover 1
Ship kit: 1
• Cooling coil 1
• Coil bracket 1
• Coolant filter 1
• 1/16-inch Vespel ferrule 2
• Port connector 1
• Stainless steel nut for 1/16-inch tubing 2
Restrictor tube 1
Machine screws, M4 x .7 12 mm 8
Installation sheet (this document) 1

2
Installing the CO2Cryogenic Oven Cooling Kit
Parts identification
Parts identification
Tools required
•Torx
®T-20 screwdriver
•Open-endwrench
•Cylinderwrench
• Long, flat-blade screwdriver
Chassis cover
Coil bracket
Cooling coil
Filter
Connector
Vespel ferrules
Machine screws
Restrictor tube
Chassis
Nuts

Installing the CO2Cryogenic Oven Cooling Kit
Overview
3
Overview
Caution Before continuing, read the safety information at the end of this document.
1. Disconnect the GC.
2. Install the inlet if you will be using a cool on-column inlet with cryo
blast or PTV inlet with cryo cooling.
3. Open the GC.
4. Install the chassis.
5. Install the restrictor tube.
6. Install the cooling coil.
7. Install the chassis cover.
8. Install the coolant filter.
9. Close the GC.
10. Connect the cryogenic coolant supply.
11. Return the GC to operating condition.
Disconnect the GC
WARNING Pressurized liquid CO2is a hazardous material. Take precautions to protect
personnel from high pressures and low temperatures. CO2in high
concentrations is toxic to humans; take precautions to prevent hazardous
concentrations. Consult your local supplier for recommended safety
precautions and delivery system design.
WARNING Do not use copper tubing or thin-wall stainless steel tubing with liquid CO2.
Both harden at stress points and may explode.
Caution Liquid CO2should not be used as a coolant for temperatures below –40°C
because the expanding liquid may form solid CO2—dry ice—in the GC oven. If
dry ice builds up in the oven, it can seriously damage the GC.

4
Installing the CO2Cryogenic Oven Cooling Kit
Install the inlet
1. Turn off the GC and unplug the power cord. Allow time for all heated
zones to cool.
2. Open the lid. If a column is installed, disconnect it at the detector end.
Remove the nut warmer, insulation, and capillary adapter, if present.
Close the lid.
3. Turn off all gases at their sources. Disconnect the carrier and detector
gas tubing from the back panel of the instrument.
Install the inlet
See the installation sheet for the particular inlet you are using to learn how
to install it.
Disconnect gas supply tubing
from these fittings

Installing the CO2Cryogenic Oven Cooling Kit
Open the GC
5
Open the GC
1. Open the lid and locate the counterbalance cam in the left rear corner
under the lid. Keeping the lid open with one hand, loosen the screw on
the right side of the cam and lower the stop plate (on the right side of
the counterbalance cam).
2. Raise the lid until it is stopped by the safety cable.
3. Raise the stop plate and tighten the screw to lock the lid in the upright
service position.
WARNING The lid is heavy. Always lock the lid when it is in the service position.
Counterbalance cam

6
Installing the CO2Cryogenic Oven Cooling Kit
Open the GC
4. Remove the seven T-20 Torx screws on the back panel. Tilt the top of the
panel away from the GC.
5. Follow the wires from the ventilating fan to the cable connector. (Not
all units have this fan.) Disconnect the cable and set the panel aside.
Remove
Cable
connector
Fan

Installing the CO2Cryogenic Oven Cooling Kit
Open the GC
7
6. Locate the plastic plug in the large hole on the left side of the GC. From
the back of the unit, depress the locking ribs on the sides of the plug
with a long, flat-blade screwdriver and remove it.
Plug
Locking ribs
Hole for
Plastic plug
was here
oven tubing

8
Installing the CO2Cryogenic Oven Cooling Kit
Install the chassis
Install the chassis
The chassis holds the cryo valve and related hardware.
1. If you are installing PTV cryo, install the valve onto the lower-left
position of the chassis, including the screws to hold it in place. See the
figure on the next page.
2. Pull any inlet cryo tube or wires through the hole on the side of the GC.
Screws to install

Installing the CO2Cryogenic Oven Cooling Kit
Install the restrictor tube
9
3. There are four mounting holes for the chassis on the left side of the GC
(two of them are in the row of ventilation slots at the top). Place the
chassis over the holes. Insert screws through the brass eyelets and
secure them loosely. The small black grommet behind the coolant outlet
union should be over the smaller hole in the side panel.
4. See the installation document for the inlet you are using to complete
this procedure.
Install the restrictor tube
1. There is a hole in the oven inside wall that lines up with the hole for
oven tubing on the side panel. Use a thin tool to make a hole through the
insulation from the interior of the oven to the grommet in the chassis.
Do not use any of the tubing to make the hole through the insulation.
2. The restrictor tube has a protective plastic cap on the long end. Push
this end with the cap in place, from inside the oven, through the hole in
the oven wall, the insulation, the hole in the side panel, and the rubber
grommet on the chassis.
3. Remove the plastic cap on the end of the tube. Install a stainless steel
1/16-inch nut and a Vespel ferrule. Insert the tube in the coolant outlet
union as far as it will go and finger tighten the nut.
Route any inlet
Coolant outlet union
Mounting holes
cryo tube or wires
through here
If PTV cryo,
install valve here
(one is behind the
valve)

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Installing the CO2Cryogenic Oven Cooling Kit
Install the cooling coil
4. Inside the oven, check that the bend on the end of the restrictor tube
points up. Tighten the union nut an additional 1/2 turn.
Install the cooling coil
The cooling coil is part of the ship kit.
1. Inside the oven, locate the coil bracket. It is secured by the same screw
that holds the bottom of the heater shroud.
Tube bends up
Heater shroud
Coil bracket