A guide how to replace ceramic burner tubes on the new Agilent 8355 SCD detector. Agilent has not made one yet.

1. How to replace ceramic burner tubes
on Agilent 8355 SCD detector
How to by Dennis Roland Hansen February 28, 2019
1
Preparations
 First of all, make sure that the heater on all parts, that you can come in contact with, are
turned off, and cooled off (<40°C). That will be the oven, inlet, detector and the burner itself.
 Always wear lint-free gloves to protect both you and the parts you are going to exchange.
 Turn off all the carrier gas flows.
 Turn off the ozone generator, and the vacuum pump.
Disassemble the burner
 All of the work have to be done with care, as the parts can be very sensible to excess force.
 Unscrew the 2 screws that hold the heat cover. Turn the heat cover slightly counter-clockwise
and lift it off and away from the burner.
Transfer line
Outlet fitting
Upper fitting

2. How to replace ceramic burner tubes
on Agilent 8355 SCD detector
How to by Dennis Roland Hansen February 28, 2019
2
 Disconnect the black transfer line on top of the burner, and put a cap on the end to keep it
safe from scratches. The best thing is to keep the transfer line as steady as possible, and not
squeeze or bend it.
 Disconnect the H2 line from the upper fitting.
 Remove the outlet fitting as careful as you can. Try not to have the upper fitting turning as
you loosen the outlet fitting.
 Take out the inner ceramic tube, and make sure to get the old O-ring out of the outlet fitting.

3. How to replace ceramic burner tubes
on Agilent 8355 SCD detector
How to by Dennis Roland Hansen February 28, 2019
3
 Remove the heat insulation cap, by turning it slightly clockwise, lift it and try to get all the
insulation wool to stay in the cap.
 Unscrew the burner oven itself from the GC, by unscrewing the nut under the burner oven.
This can be a little bit tricky, and you might have to bend a wrench to get an easier access to
the nut.

4. How to replace ceramic burner tubes
on Agilent 8355 SCD detector
How to by Dennis Roland Hansen February 28, 2019
4
 Carefully pull out the large ceramic burn tube out of the burner oven by pulling the upper
fitting.
 Remove the upper fitting by unscrewing it from the nut that holds the large ceramic burn tube.

5. How to replace ceramic burner tubes
on Agilent 8355 SCD detector
How to by Dennis Roland Hansen February 28, 2019
5
 Remove the nut from the large ceramic burn tube and remove the graphite ferrule, make sure
to get it all out without damaging the nut.
 There is also a graphite ferrule at the bottom of the burner oven. It has to be removed as
well.
Insert new large ceramic burn tube
 Insert new graphite ferrules into the nut and at the bottom of the burner oven.
 Insert a new large ceramic burn tube and carefully place the burner oven back onto the GC.
When placed correctly screw the nut under the burner oven back onto the GC.

6. How to replace ceramic burner tubes
on Agilent 8355 SCD detector
How to by Dennis Roland Hansen February 28, 2019
6
 Reapply the heat insulation cap back onto the GC and try to get the insulation wool to cover
all the way around. Apply extra wool if needed.
 Place the upper fitting on top of the large ceramic burn tube and gently tighten the nut onto
the upper fitting. Do not overtighten. The large ceramic burn tube and the upper fitting will get
into the right position automatically.
 It is a good idea if the direction of the upper fitting is aligned in the same direction as the
power line on the burner oven. This will make it easier to connect the H2 line when the heat
cover is back on.
 Put the heat cover back around the burner oven, and turn it clock-wise to secure it onto the
GC. Screw the two screws back into the heat cover.
 Connect the H2 line to the upper fitting. Do not overtighten.
Insert new inner ceramic tube
 Get a new inner burn tube and gently place the O-ring > 5 mm from one end over the burn
tube. The burn tube will get the right adjustment in the next step installing the outlet fitting
back on the upper fitting.

7. How to replace ceramic burner tubes
on Agilent 8355 SCD detector
How to by Dennis Roland Hansen February 28, 2019
7
 Insert the new inner ceramic tube into the burner ad let it rest on the O-ring.
 Place the outlet fitting on top of the ceramic tube. When you tighten the outlet fitting gently,
the ceramic tube will get into the right position on its own. Make sure you don’t overtighten
the outlet fitting, finger-tight and a small notch should do the trick.

8. How to replace ceramic burner tubes
on Agilent 8355 SCD detector
How to by Dennis Roland Hansen February 28, 2019
8
Reassemble the burner
 Reconnect the black transfer line into the outlet fitting, try keeping the transfer line as steady
as possible, while doing so. Make sure you don’t overtighten, finger-tight and a small notch
should do the trick.
 Turn on the carrier gas flows again.
 Turn the ozone generator back on.
 Check for leaks.