Figure 1FID EPC flow control manifold replacement kit
Slot for label tag
7/16 inch hex nuts
Top rear panel
1
Tools required
7/16 inch open-ended wrench
T-20 Torx driver
Needle-nosed pliers
Safety information
Before continuing, read the safety information in your GC Operating Manual.
Removing the existing manifold
WA R NI N GHydrogen gas is flammable and potentially explosive. Before replacing the
manifold, turn off the hydrogen gas at the source.
WA R NI N GBefore proceeding, turn off the oven and any heated zones and let them cool
down. Turn off all detector gases at their supply, then turn off the main power
switch and unplug the power cord.
1.Remove the pneumatics cover and the RFI shield under it. See Figure 2.
Pneumatics cover
RFI shield
Figure 2Back view of HP 6890
2
Top rear panel
2.Remove the gas supply tubing from the present manifold. See Figure 3.
Disconnect gas lines
OR
Disconnect gas lines
Manifold, installed before May 1998
Figure 3Remove the gas connections
3.Remove the detector cover and the top rear panel.
4.Remove the Torx T-20 mounting screw from the front of the manifold. See
Figure 4.
Figure 4Removing the detector flow manifold
5.Disengage the detector tubing from the slots in the chassis so that the gang
fitting on the manifold can be removed easily. See Figure 4.
Manifold, installed after May 1998
Torx T-20 screws
holding detector manifolds
3
CautionMake sure you are properly grounded with an ESD strap before continuing.
6.Unlock the detector manifold’s ribbon cable from the pneumatics control
board and detach the connector. The adjacent ribbon cable may have to be
removed as well.
7.If you are removing a manifold that was installed before May 1998, slide it
a few centimeters out of its slot in the pneumatics carrier. See Figure 5.
8.Remove the one Torx T-20 screw holding the gang fitting on the manifold.
See Figure 5.
CautionDo not lose the O-rings under the gang fitting.
Remove screw
and gang fitting
OR
Manifold, installed before May 1998Manifold, installed after May 1998
Figure 5Removing the gang fitting
4
Installing the new manifold
CautionAlways hold the manifold by its support bracket to avoid damaging board
components.
1.Slip the ID tag on the new manifold through the slot in the mounting bracket,
then align the bracket holes over the gas fittings. Secure the bracket with
three 7/16 inch hex nuts. See Figure 6.
Mounting bracket
Gang fitting
installs here
7/16 inch hex nuts
ID tag
through slot in bracket
Ribbon cable
Figure 6Bracket mounted onto the manifold
2.Peel the blank label from its backing and paste it on the mounting bracket
over the screw heads. See Figure 7.
3.If the tubing from the gang fitting bends to the left, reshape it so that it bends
up and back from the block as shown in Figure 8.
5
4.Insert the gang fitting through the cutout in the manifold bracket and install
it onto the new manifold assembly so that the tubing runs back and away
from the fitting.
•Be sure the left tube clears the inner edge of the bracket. See Figure 8.
•Be sure that the O-rings are in place.
Tighten the gang fitting screw firmly to compress the O-rings.
5.Route the ribbon cable behind the manifold assembly as shown in Figure 7.
Then, slide the manifold and bracket assembly into the slot until the bracket
seats flush against the end of the rails. See Figure 8.
Back view of manifoldManifold installed with cable routed to left
Figure 7Routing the ribbon cable
6
Route tubing along
this path
Check for interference
Bracket is flush with
carrier rails
Attach gang fitting
Figure 8Manifold, after installation
6.Route the gas tubing behind the manifold, over the top of the chassis, and
through the slots as shown in Figure 4 and Figure 8.
7.Connect the ribbon cable to the mating connector on the pneumatics board.
Arrange the cable to keep it away from the valves and keep it from being
pinched against the manifold.
For the back detector, you may want to loosen the manifold and slide it out
of the carrier a few centimeters to connect the cable to the pneumatics
board. Then, reinstall the manifold.
8.Secure the manifold in place using the Torx T-20 screw. See Figure 4.
9.Using a pair of needle-nosed pliers, remove the appropriate top rear panel
detector cutout for the FID. Also remove any cutouts needed to access other
manifolds or accessories installed in the GC. See Figure 9.
7
Insert tip of
pliers here
Back inlet
Front detector
Auxiliary
Left most screw slot
Back detector
Front inlet
Figure 9Top rear panel cutouts
10. Place the new top rear panel on its left-most mounting screw. Use the screw
as a hinge and angle the panel while sliding each manifold ID tag through
its cutout in the panel, working from left to right. When all the tags are
through the panel, finish installing the panel on the GC.
11. Install the RFI shield, the pneumatics cover, and the detector top cover.
12. Connect the source gas lines to the manifold. See Figure 10.