Replacing The Sample Tube O-Ring - Micromeritics Gemini VII 2390a Operator's Manual

Gemini VII

Replacing the Sample Tube O-ring

It is important to maintain a vacuum-tight seal near the top of the sample tube stem. If an O-ring
becomes worn or cracked, it does not provide a good seal and will need to be replaced.
Before removing (or installing) a sample tube, ensure that the port valve is closed.
Observe the instrument schematic to verify valve status.
1. Holding the sample tube firmly with one hand, loosen the sample tube connector nut by turning
counterclockwise.
Be careful not to let the sample tube connector nut drop onto the bottom of the tube as
it may break the tube.
Be sure to use the proper size frit for the sample port. The instrument will not operate
properly if the incorrect frit size is used.
2. Carefully pull the sample tube down until it is free from the port. It may be necessary to grasp the
sample tube with both hands.
3. Remove the O-ring from the top of the sample tube and replace it with a new one.
If the O-ring remains inside the sample port, use a pair of tweezers or needle-nose
pliers to remove it.
4. After the new O-ring is in place, insert the sample tube back into the sample port until it is fully
seated.
5. Slide the sample tube connector nut up the tube (the ferrule and O-ring will move along with the
connector nut). Then, turning clockwise, hand-tighten the connector nut to the sample connector.
239-42828-01 - Dec 2012
Preventive Maintenance
O-ring
Ferrule
Connector nut
9-7