Replacement of SCD Outer Pyrotube

Required devices

No.
Parts name
Category
Required number
Note
Inner Pyrotube
1
PTFE Ferrule
1
Spanner, SCD, Maintenance
1
Spanner, SCD
1
Tweezers
1
Outer Pyrotube
1
O-ring, 4D P3
1

Procedures

Step 1

On the instrument monitor or workstation, check that the temperature of the column oven is lower than 40 °C, and check that the temperatures of the injection port and detector (SCD-IF part and electric furnace) are 50 °C or lower.
After checking the temperatures, turn OFF the main power to the instrument.

Step 2

Open the side cover.

Step 3

Remove the transfer line (★1).

While holding the transfer adapter (★2), loosen the transfer line (★1) and remove it.

Step 4

Remove the transfer adapter (★2) and inner pyrotube (①).

While holding the reductant inlet (★3) with a spanner, SCD (④), loosen the transfer adapter (★2) with a spanner, SCD, maintenance (③) and then remove the transfer adapter (★2) together with the inner pyrotube (①).


Hint

If you cannot remove the inner pyrotube with the transfer adapter, remove the inner pyrotube with tweezers.

Step 5

Loosen and remove the reductant inlet with a spanner, SCD (④).


Step 6

Remove the outer pyrotube (⑥) with tweezers (⑤).

Step 7

Install a new O-ring (⑦) on the outer pyrotube (⑥) for replacement.

Hint

Install the O-ring about 3 mm from the end.

Step 8

Insert the outer pyrotube (⑥) in the SCD.

Step 9

Ensure that the O-ring hits the back.

Check that it hits the back as shown in the following figure.

Note

When the O-ring does not hit the back, the end of the outer pyrotube interferes with the parts inside the SCD as shown in the following figure.


In this case, turn the outer pyrotube several times while pushing it against the back.

Step 10

Install the reductant inlet.

Tighten it by hands and then additionally tighten it with a spanner, SCD (④).

Step 11

Detach the transfer adapter from the inner pyrotube.

Step 12

Detach the PTFE ferrule (②) from the transfer adapter (★2) and remove the back ring (★4).

Hint

Removed back ring will be used in the step 14.

Step 13

Install a new PTFE ferrule (②) on the inner pyrotube (①) for replacement.

Step 14

Install the back ring removed in the step 12 on the inner pyrotube.

Step 15

Install the transfer adapter on the inner pyrotube.

Step 16

Push the inner pyrotube in with the transfer adapter.

Step 17

While pushing the inner pyrotube (①) in with the transfer line (★1), tighten the transfer adapter (★2).

Tighten the transfer adapter (★2) completely by hand until it stops.

Step 18

Additionally tighten the transfer adapter.

After tightening it by hand until it does not turn anymore, give additional tightening of half turn with a spanner, SCD, maintenance (③).

Step 19

Install the transfer line by hand-tight.

Step 20

Close the side cover.

Step 21

Turn on the main power of the instrument and start the GC.

Note

After the SCD startup is completed, condition it for about 12 hours under the analysis conditions. After replacing the pyrotube, it takes time until the sensitivity is recovered.