venting_pumping_object_box
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| Both sides previous revision Previous revision Next revision | Previous revision Next revision Both sides next revision | ||
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venting_pumping_object_box [2023/06/01 13:43] swartzj |
venting_pumping_object_box [2023/11/17 11:23] swartzj |
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| The procedure is then as follows: | The procedure is then as follows: | ||
| - Close the valve to the roughing pump RV. | - Close the valve to the roughing pump RV. | ||
| - | - Now you can plot the pressure at BPG to monitor the pressure before you open the vent valve. | + | - Now you can plot the pressure |
| - **Keep a constant eye on the pressure level** as it increases rapidly. When it approaches 800 torr, **it is imperative that you close the venting valve.** Failure to do so will result in over-pressure in the chamber since it will continue to be filled with dry nitrogen. | - **Keep a constant eye on the pressure level** as it increases rapidly. When it approaches 800 torr, **it is imperative that you close the venting valve.** Failure to do so will result in over-pressure in the chamber since it will continue to be filled with dry nitrogen. | ||
| - You can now enter and open the chamber. | - You can now enter and open the chamber. | ||
| Line 18: | Line 18: | ||
| From S800 Vacuum Main Page, go to Object chamber page. This will open the page in the figure below. | From S800 Vacuum Main Page, go to Object chamber page. This will open the page in the figure below. | ||
| * Make sure that the IG is off. | * Make sure that the IG is off. | ||
| - | * When you start, you should have RV closed, FV open and the TGV valve, Vent valve, as well as the gate valves named D2341 BGV and D2303 BGV all closed. | + | * When you start, you should have RV closed, FV closed |
| - | * Close FV and open RV to start pumping down the object chamber with the roughing pump. You can make a plot of the pressure at BPG at this point. | + | * Open RV to start pumping down the object chamber with the roughing pump. You can make a plot of the pressure |
| * Section D2337 will initially be red with vacuum status: 'Bad vacuum' | * Section D2337 will initially be red with vacuum status: 'Bad vacuum' | ||
| - | * The vacuum reading at FPG needs to drop to below 200 mTorr before you can safely turn on the turbo pump. | + | * Wait until the vacuum reading at FPG to drops to below 200 mTorr before you can safely turn on the turbo pump. |
| * After turning on the turbo pump, wait for the inner circle of the pump symbol to turn green and the pump to reach 40 000 rpm before you open the valve at TGV. | * After turning on the turbo pump, wait for the inner circle of the pump symbol to turn green and the pump to reach 40 000 rpm before you open the valve at TGV. | ||
| * When the pressure decreases to below 10-3 Torr, you should see the pressure bottom out on your BPG plot, you can turn on the IG and also plot its pressure over time. Section D2337 should turn green and the vacuum status should turn to 'Good vacuum' | * When the pressure decreases to below 10-3 Torr, you should see the pressure bottom out on your BPG plot, you can turn on the IG and also plot its pressure over time. Section D2337 should turn green and the vacuum status should turn to 'Good vacuum' | ||
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venting_pumping_object_box.txt · Last modified: 2024/02/06 10:40 by noji
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