Agilent Technologies 6850 GC User manual

Agilent Technologies
Agilent 6850 GC
Sampling Valves
G2654A - G2659A
G2667A - G2672A
Installation

2Installing Sampling Valves
Notices
© Agilent Technologies, Inc. 2012
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Manual Part Number
G2630-90160
Edition
Second edition, May 2012
First edition, November 2003
Printed in USA
Agilent Technologies, Inc.
2850 Centerville Road
Wilmington, DE 19808-1610 USA
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met.

3
Agilent 6850 GC Sampling Valves
Installation
Agilent Technologies
Installing Sampling Valves on an
Agilent 6850 Gas Chromatograph
G2654A -G2659A
G2667A - G2672A
Installation Kits 4
Tools required 5
Safety information 5
Part Identification 6
Common parts 6
Sampling valves 7
Air control valves 8
Installing a Sampling Valve 9
Installing an Air Control Valve for a Diaphragm-Type Control Valve 15
Installing an Air Control Valve for a Rotary-Type Sampling Valve 17
This document describes installation of a gas or liquid
sampling valve on an Agilent 6850 gas chromatograph
already equipped with either a packed or capillary inlet.

4Installing Sampling Valves
Installing Sampling Valves on an Agilent 6850 Gas Chromatograph
Installation Kits
Six installation kits are available (Table 1).
Except for the sampling valve itself, which is different for
each kit, all kits contain the same items (Table 2).
Table 1 Valve installation kits
Description Inlet Assessory number rotary Accessory number diaphragm
Gas sampling valve, 6-port Packed G2667A G2654A
Gas sampling valve, 6-port Capillary G2668A G2655A
Liquid sampling valve, 4-port, 0.5 µL Capillary G2669A G2656A
Liquid sampling valve, 4-port, 1.0 µL Capillary G2670A G2657A
Liquid sampling valve, 4-port, 0.5 µL Packed G2671A G2658A
Liquid sampling valve, 4-port, 1.0 µL Packed G2672A G2659A
Table 2 Kit contents
Description Qty
Gas or liquid sampling valve and heated valve box 1
Modified lid top cover 1
Lid cam, valve box version 1
Air control valve assembly 1
Air control valve cover plate (diaphragm only) 1
Air control valve torque plate (diaphragm only) 1
10-feet plastic actuator tubing 1
Screw, M4 x 0.7, 12 mm length, pan head 9 (diaphragm)
5 (rotary)
Screw, M4 x 12, T-20 Torx 8
Installation sheet (this document) 1

Installing Sampling Valves on an Agilent 6850 Gas Chromatograph
Installing Sampling Valves 5
Tools required
•Torx T- 10 driver
•Torx T- 20 driver
•Open- end wrenches
•Inlet wrench (for capillary inlet)
Safety information
Before continuing, read the safety information on your
Agilent 6850 Gas Chromatograph User Information
CD- ROM.
WARNING
Before proceeding, turn off the oven and any heated zones and let
them cool down. Turn off all gases at their source, then turn off the
main power switch and unplug the power cord.

6Installing Sampling Valves
Installing Sampling Valves on an Agilent 6850 Gas Chromatograph
Part Identification
Common parts
These are parts that are used with all gas and liquid
sampling valves (Figure 1).
Figure 1 Common parts
Counterbalance cam
Torque plate (diaphragm only)
Cover plate (diaphragm only)
Screws, pan-head
Screws, Torx, for lid
Modified lid top cover
Plastic tubing for
actuator air

Installing Sampling Valves on an Agilent 6850 Gas Chromatograph
Installing Sampling Valves 7
Sampling valves
Parts for liquid and gas sampling valves are shown below.
See Figure 2 and Figure 3.
Figure 2 Valves with capillary inlet
Heated sampling valve
Heater/Sensor cable
To air control valve
Sample in/out ports Gang block fitting
Split trap fitting
Valve insert weldment
This is a liquid sampling valve. Gas sampling valves do not
have the adjustable restrictor between the sample ports.
Figure 3 Valves with packed inlet
Heated sampling valve
To air control valve
Packed inlet
Heater/Sensor cable
Gang block fitting
Heater/Sensor cable
Sample in/out ports
This is a gas sampling valve. Liquid sampling valves have an
adjustable restrictor in the hole between the sample ports.

8Installing Sampling Valves
Installing Sampling Valves on an Agilent 6850 Gas Chromatograph
Air control valves
Parts for the air control valves are show below. See Figure 4
and Figure 5.
Figure 4 Air control valve for a rotary sampling valve
Figure 5 Air control valve for a diaphragm sampling valve
Air control valve
Air control cable
To heated sampling valve
Air control valve
Air control cable
To heated sampling valve

Installing Sampling Valves on an Agilent 6850 Gas Chromatograph
Installing Sampling Valves 9
Installing a Sampling Valve
The sampling valve is installed in a heated valve box on top
of the GC. See Table 3. The box and valve is a
factory- assembled and leak- tested unit. Installation does not
require any disassembly of the unit. See the 6850 Gas
Chromatograph User Information CD- ROM.
The valve is plumbed through an existing inlet, either
capillary or packed.
Table 3 Installing a sampling valve
Step Action Notes
1Remove the lid top cover. aRemove vent tubing, if present.
bRemove detector cover.
cRemove 8 T-20 Torx screws.
dRemove top cover.
2If the valve is to replace a capillary
inlet, remove the insert weldment
and split vent trap.
If the valve is to replace a packed
inlet, continue at Step 3.
aUse the inlet wrench to release the
large nut on the inlet insert weldment.
bLift the inlet insert weldment clear of
the inlet.
Detector cover
T-20 Torx screw
(1 of 8)
Vent tubing,
if present

10 Installing Sampling Valves
Installing Sampling Valves on an Agilent 6850 Gas Chromatograph
cRemove the gang block fitting from the
inlet flow module.
•Be very careful not to lose the small
O-rings.
dRemove the split vent trap bracket
using a T-20 Torx driver.
Table 3 Installing a sampling valve (continued)
Step Action Notes
Large nut
Inlet insert weldment
Inlet flow module
Gang block fitting

Installing Sampling Valves on an Agilent 6850 Gas Chromatograph
Installing Sampling Valves 11
eDisassemble the split vent trap.
fRemove the inlet insert weldment and
attached parts from the instrument.
gContinue at Step 4.
3If the valve is to replace a packed
inlet, remove the existing inlet.
aOpen the lid. Disconnect the column
from the inlet.
bRemove the insulation cup and
insulation from the inlet column fitting.
cClose the lid.
dTrace the heater/sensor cable from
the inlet to the wiring harness.
Disconnect it.
eTrace the gas lines from the inlet to the
gang fitting on the flow module.
Disconnect the gang fitting.
fRemove the three screws holding the
inlet.
gRemove the inlet.
hContinue at Step 4.
•Note where the heater/sensor
cable plugs into the wiring harness.
You will use this location later.
•Do not remove the insulation in the
hole under the inlet.
4Lock the lid in the service position. aOpen the lid. Locate the
counterbalance cam.
bLoosen the screw on the right side of
the cam and lower the stop plate.
The cam is under the lid, in the left rear
corner.
Table 3 Installing a sampling valve (continued)
Step Action Notes
Split vent trap
Split vent
trap bracket

12 Installing Sampling Valves
Installing Sampling Valves on an Agilent 6850 Gas Chromatograph
cRaise the lid until it is stopped by the
safety cable.
dRaise the stop plate and tighten the
screw to lock the lid in the upright
service position.
•The lid is heavy. Always lock the lid
when it is in the service position.
5Replace the lid counterbalance
cam.
aLocate the two cam mounting screws.
(one in front, one in back).
bWhile an assistant supports the lid,
remove the two mounting screws and
the cam.
cRemove the stop plate and screw from
the cam. Install them on the new cam
from the kit.
dInstall the new cam. Lower the stop
plate.
ePull the lid forward until the cam
follower rests on the curved surface of
the cam in front of the stop plate.
fRaise the stop plate and tighten the
screw. Close the lid.
•Do not try to change the cam alone.
Obtain help to hold the lid in the
upright position while the cam is
changed, since the lid is
unsupported while doing this.
•The pointed end of the top plate is
up and the side with the screw
recess is visible when installed.
Table 3 Installing a sampling valve (continued)
Step Action Notes
Cam follower
Stop plate and screw
Counterbalance cam
Cam mounting screw
(1 of 2)
Lid

Installing Sampling Valves on an Agilent 6850 Gas Chromatograph
Installing Sampling Valves 13
6Install the valve and valve box. aConnect the valve gang block fitting to
the inlet flow module.
bPlace the valve box on the lid between
the inlet assembly and the inlet flow
module.
cBend the heater/sensor cable to the
rear.
dAttach the valve box tabs to the lid
using four pan-head screws.
•Be sure that the small O-rings are
in place and that the hole patterns
in the fitting and the flow module
are aligned.
•Orient the valve box so that the
sample connections point to the
rear of the GC.
•Be sure that no tubing or wiring is
trapped under the valve box.
•The metering valve shown below is
not present on gas sampling valves.
Table 3 Installing a sampling valve (continued)
Step Action Notes
Sample connections
Inlet flow module
Metering valve
Heater/Sensor
Mounting tabs
(some not visible)
Inlet assembly
cable

14 Installing Sampling Valves
Installing Sampling Valves on an Agilent 6850 Gas Chromatograph
7Connect the plumbing. a Capillary inlet only.
•Place the valve insert weldment
attached to the valve box on the
inlet and tighten the large nut.
b Packed inlet only.
•Place the new inlet attached to the
valve box in the opening where the
old one was. Secure the inlet with
three screws.
•Slide the insulation and insulation
cup up over the inlet fitting and
secure it to the oven top.
8Connect the valve box
heater/sensor cable.
aLocate the connector marked A on the
main wiring harness.
bConnect the valve box heater/sensor
cable.
9Complete the inlet installation. a Capillary inlet only.
•Reassemble the split vent trap
using the trap fitting attached to
the valve box.
•Secure the split vent trap bracket
and the trap.
b Packed inlet only.
•Connect the inlet heater/sensor
cable where the original inlet cable
was connected.
Table 3 Installing a sampling valve (continued)
Step Action Notes
Connector A

Installing Sampling Valves on an Agilent 6850 Gas Chromatograph
Installing Sampling Valves 15
Installing an Air Control Valve for a Diaphragm-Type Control Valve
Follow the procedure in Table 4 to install a diaphragm air
control valve.
Table 4 Installing an air control valve for a diaphragm-type control valve
Step Action Notes
1Install the air control valve. aIf present, remove the rectangular
cover plate on the back of the lid.
bAttach the torque plate to the inside of
the cover plate with one screw. Do not
tighten.
cMount the cover plate/torque plate
assembly on the outside of the lid with
two screws.
dLoosen the two screws on the base of
the air control valve.
Torqu e p l a t e
Connector
Gas fitting
Tubing to valve box
Mounting screws

16 Installing Sampling Valves
Installing Sampling Valves on an Agilent 6850 Gas Chromatograph
eSlide the valve onto the bracket on the
inside of the cover plate. Tighten the
valve base screws and the torque plate
screw.
fConnect the cable from the air control
valve to the wiring harness.
•Move the valve and torque plate as
needed to pass the gas fitting
through the opening in the torque
plate.
2Install the modified top cover. aPlace the modified lid top cover
supplied in this kit on top of the lid.
bSecure with eight screws.
3Connect the actuator air. aConnect the air source to the fitting on
the back of the lid (their control valve).
bSet the source delivery pressure at 310
to 345 kPa (45 to 50 psi).
•Valves are gas-driven, usually by
compressed air. There is no high
purity requirement for this gas. The
supply pressure may surge as the
valve operates, so the actuator gas
must not come from the FID air.
4Finishing up. aRestore carrier and other gases to the
instrument.
bRestore power.
cApply your normal operating
procedures. Leak-check all new
connections.
Table 4 Installing an air control valve for a diaphragm-type control valve (continued)
Step Action Notes
Harness
Connector

Installing Sampling Valves on an Agilent 6850 Gas Chromatograph
Installing Sampling Valves 17
Installing an Air Control Valve for a Rotary-Type Sampling Valve
Follow the procedure in Table 5 to install a rotary air
control valve.
Table 5 Installing an air control valve for a rotary-type sampling valve
Step Action Notes
1Install the air control valve. aIf present, remove the rectangular
cover plate on the back of the lid.
bLocate the two tubes from the heated
sampling valve. Run them through the
hole on the back of the lid.
cInsert the tubes in the numbered holes
on the air control valve. Press firmly
into place. Tug on the tube to verify it is
connected.
•The tubes are labeled “1” and “2”.
Connect each tube to the hole on
the air control valve with the
corresponding number.
•Press in the black PTFE ring to
release the tube if you need to
remove it.
dMount the valve assembly on the
outside of the lid with two screws.
•Install the air control valve with the
holes facing down.
Insert tubes here
PTFE ring

18 Installing Sampling Valves
Installing Sampling Valves on an Agilent 6850 Gas Chromatograph
2Connect the control cable. •Connect the cable from the control
valve to the wiring harness.
3Install the modified top cover. aPlace the modified lid top cover
supplied in this kit on top of the lid.
bSecure with eight screws.
4Connect the external actuator air
supply tubing.
aConnect the air source to the fitting on
the back of the lid (the control valve).
bSet the source delivery pressure at 310
to 345 kPa (45 to 50 psi).
•Valves are gas-driven, usually by
compressed air. There is no high
purity requirement for this gas. The
supply pressure may surge as the
valve operates, so the actuator gas
must not come from the FID air.
5Finishing up. aRestore carrier and other gases to the
instrument.
bRestore power.
cApply your normal operating
procedures. Leak-check all new
connections.
Table 5 Installing an air control valve for a rotary-type sampling valve (continued)
Step Action Notes
Harness
Connector

Installing Sampling Valves on an Agilent 6850 Gas Chromatograph
Installing Sampling Valves 19

© Agilent Technologies, Inc.
Printed in USA, May 2012
Agilent Technologies
G2630-90160