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| Step # | Description | Notes / Reasons |
|---|---|---|
| 1 | If the LN2 level is >30%, turn ON the purifier heaters by clicking both "Heater MC Cycle" and "Heater MC Stop at SP". | It shortens the time when the liquefiers are in "Idle" in later steps. |
| 2 | Turn OFF the purifier heaters once the LN2 level gets 30%. | It usually takes about 5 hours (not confirmed recently) to bring the level from 100% to 30%. |
| 3 | Switch both the liquefiers to "Run + Auto + Idle". | Ensure the solenoid valves V9a and V21a are open. |
| 4 | Close BV02 manually. | This is to isolate both Liquefiers from the purifier |
| 5 | Close V30 hand valve on HR3. | This is to isolate the outside gHe tank from the purifier. Note: At this time purifier helium space's pressure would be same as the tank pressure |
| 6 | Open SV01 on QT-HMI main manifold | This is to open the path from the outlet of the purifier to the Vvent |
| 7 | Crack open Vvent while someone watching P40 pressure gauge on HR3 front panel | This is to bring down the pressure inside the purifier as a preparation to open V10a. Bring the P40 down as much as you can (preferred below 10 psig). If it doesn't go down, it is because to 10-20 psig. The pressure change might be slow, as cold gHe is expanding. In that case leave the Vven cracked open. It might take 5-10 minutes. Don't close SV01 to control the flow/pressure, since it might cause contamination between SV01 and V10a. |
| 8 | Open V10a on QT-HMI screen | This will make a noise because a sudden relieving of the pressure in the purifier helium space via V10a. |
| 9 | Close Vvent hand valve | |
| 10 | Close V35 hand valve | Now the purifier helium space is isolated from the rest of the system and opened to the atmosphere via V10a |
| 11 | Write down the LN2 level in the purifier on the records sheet | Find this binder on the HR3 top |
| 12 | Ensure VNVA is open, and then Turn ON the purifier heaters, by clicking both "Heater MC Cycle" and "Heater MC Stop at SP".
| The LN2 level will start decreasing slowly, and the "TA_Top" and "TA_Bot" temperatures increasing slowly. It usually takes about 24 hours (not confirmed recently) for the temperatures to go above ~274K. |
| 13 | Connect the pump/purge setup (small manifold with pump, gHe cylinder, pressure gauge, and hand valves) to the V10a outlet port. |
You need not wait until TA_Top and TA_Bot temperatures reach ~274K. |
| 14 | Start the pump and open the hand valve connected to the pump. | The heater on purifier LN2 is ON. |
| 15 | Wait until the pressure on the gauge reaches the lowest (usually it takes about 15-20 mins). | |
| 16 | Close the black-hand-valve to the green pump | |
| 17 | Regulate the pressure of the gHe bottle ~3 psi and then open the blue-hand-valve to purge the purifier gHe space. | |
| 18 | Close the blue-hand-valve when the pressure gauge reads ~3 psi. | |
| 19 | Open the black-hand-valve to start pumping down. | |
| 20 | Repeat Steps 15 → 19 as many times as you want. Or leave it pumping over night with the heaters ON | 3 days of pumping down (or more) would be recommended for a thorough cleaning |
| 21 | After being done with the last cycle of pumping, Close the black-hand-valve to the green pump. | |
| 22 | Regulate the pressure of the gHe bottle ~3 psi and then open the blue-hand-valve to purge the purifier gHe space. | |
| 23 | Close v10a on QT-HMI screen | |
| 24 | Open V30 hand-valve slowly until it is fully opened | |
| 25 | Open v35 hand-valve slowly until it is fully opened | Once you open V35, the line up to BV02 and Vvent will be pressurized. |
| 26 | Check the pressures on p41 and p40 on the HR3 front. Both should read the same value. If it does not read the same value, then proceed again with Step 1, otherwise proceed to the next step. | |
| 27 | Detach the pump/purge manifold if you are not going to perform purifier regeneration again soon. | |
| 28 | Ensure SV01 is open | This is to bleed gHe to ensure the atmosphere is not trapped in the piping section up to BV02 |
| 29 | Crack open Vvent and flush/bleed gHe through Vvent for a few seconds | You can open and close that Vvent valve to pressure purge |
| 30 | Close Vvent hand valve | |
| 31 | Following the procedure, fill the purifier using the warm purifier up to 90% filling procedure | Note: During this process, purifier can go to the Alarm mode. If it does so, reduce the pressure in the purifer and clear the Alarm on "Purifier Alarm Page" and open V9a and V21a valves (these valves will be closed when purifier goes to the Alarm mode) |
| 32 | Once the purifier is filled with LN2 up to 90% level, then ensure V9a and V21a are opened | |
| 33 | Perform the steps 26 and 27 again to clean the line with purified gHe | |
| 34 | Close SV01 | |
| 35 | Open SVSAMPLE followed by the green pressure regulator and the flow-meter to have a flow to the purity meter and ensure you can read 100% or slightly above. | Also use the portable purity meter setup to confirm the purity with PM01. There is a port you can connect the portable purity meter to the QT-HMI cabinet which is the same line as to PM01. So, just open SVSAMPLE + green hand valve + flow-meter (as same as for PM01) |
| 36 | Close SVSAMPLE | You can leave the green-hand valve and flow-meter opened so you can remotely open SVSAMPLE at anytim to measure the purity of the purified helium from the purifier |
| 37 | Open BV02 hand-valve slowly until it is fully opened | Now purifier regeneration is comple. Don't forget to write down the date,time, cycles on the binder sheets for maintenance |
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