Replacing The Catalyst Tube; Cautions; Maintenance And Service - RESTEK CH4izer Manuel D'utilisation

9.0 Replacing the Catalyst Tube

When conversion performance of the catalyst material becomes significantly degraded, replace the catalyst tube.
WARNING: The catalyst chamber and all associated fittings can be extremely HOT! Allow the actual temperature on the controller
box and the GC oven to cool down to 50 °C or less before attempting to touch any part of this assembly.
9.1 Set the GC oven to 25 °C and cool down the methanizer heater chamber by pushing the RUN button on the controller box to
turn the heater off. Observe the actual temperature displayed on the controller box display (Figure 11) and do not touch until
the GC oven and catalyst heater chamber have cooled down to 50 °C or less.
9.2 Locate the hydrogen supply line and turn off the flow of hydrogen.
9.3 Using two wrenches against each other, remove the analytical column from the catalyst tube.
9.4 Using two wrenches against each other, loosen the bottom nut of the catalyst tube that is connected to the methanizer's
hydrogen supply line. Remove the hydrogen supply line.
9.5 Using two wrenches, loosen the top nut of the catalyst tube connecting the adaptor for capillary (or packed) FID. Remove the
heater chamber and slide the catalyst tube out of the bottom of the heater chamber.
9.6 Replace the catalyst tube with a new one, keeping the support ring of the catalyst tube towards the bottom of the heater chamber.
9.7 Reassemble the methanizer components following the directions in section 5.0 (Installation Guide).

10.0 Cautions

10.1 Even small amounts of sulfur compounds can poison the nickel catalyst, and a poisoned catalyst must be replaced as it cannot
be regenerated. If sulfur compounds are present in a sample, the catalyst should be bypassed using a switching valve or by
backflushing the column.
10.2 Hydrogen gas in the presence of the hot nickel catalyst is a reducing agent. Operators should bypass the catalyst when analyzing
samples containing compounds that are easily reduced, such as carboxylic acids or unsaturated hydrocarbons.

11.0 Maintenance and Service

11.1 All maintenance and servicing of the controller box will be performed at Restek.
11.2 For your safety, DO NOT open the controller box. Opening the controller box will void the warranty. If the unit is opened, first
disconnect it from the electrical supply in order to prevent a shock hazard.
11.3 For questions, problems, or repair services, contact Restek Technical Service at 1-800-356-1688 or 1-814-353-1300, ext. 4 within
the U.S. Outside the U.S. please contact your Restek representative.
11.4 DO NOT replace main supply cords with inadequately rated cords. Only use cords supplied by Restek.
11.5 To prevent injury and/or burning yourself when replacing the catalyst, confirm that the catalyst chamber and GC oven have
cooled to 50 °C or less prior to touching any parts. Note that the actual temperature of the catalyst is displayed on the front of
the controller box.
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