- Ensure MV101, MV103 are closed. (This is to isolate the outside gHe tank).
- Turn OFF the Kaser Comprssor (HR3)
- Ensure V30 and V35 are also closed. (This is to isolate the purifier).
- Connect an oil pump to the buffer tank's VBT outlet.
- Connect He bottle to Helium purge Inlet
- Open the He bottle to 10 psig
- Open the valve on the buffer tank and start the vacuum
- Monitor the pressure on the buffer tank and let it go up to ~ 0.2 psi
- Close "Vfill" and pump the lines and monitor the buffer tank pressure to go up to 0.2 psig
- Pump back the lines by opening Vfill and monitor the buffer tank pressure to go up to ~ 10 psi
- Do the pump and purging for 3 cycles
Steps for pump and purge:
- Close the hand valve from the pump
- Set the He gas cylinder to 10 psig
- Open VFill slightly
- Open the yellow color hand valve L7B while watching the gauge
- Once it's pressurized (check pressure from the pump) close Vfill and L7B
- Close VBTv on the buffer tank
- Disconnect the line from the pump and connect to the purity meter
- Crack open VBTv and check the purity, and ensure it is approximately equal (or close) to the reference purity from a gHe cylinder.
- Open L7B and disconnect the purity meter.
- If there is no further cleaning, then crack open MV103 to bleed (to clean the pipe from the outside gHe tank), and close MV103.
- After closing MV103, then open MV101.
- Similarly, Open MV102 (from the "return" path of the gHe tank), and bleed from V17, then close V17
- Open V30 and V35.