Purging HR3 after a maintenance

Conditions: HR3 is OFF

1. Close MV101 (supply) and MV102 (return) 
2. Connect a He cylinder to L3 (Helium purge inlet) - Regulate 10 psig

      3. Open Vmup

      4. Ensure V30, V35, V9a, V21a, V11A, V14, SV03, REGX, V14 are open 

      5. Open VHSV and the rotatable valve on the top of the line

      6. Check the gauge and make sure that it reads 10 psig

      7. Start HR3

      8. Slowly open V17 and vent

Measuring the purity:

Measure from SVSAMPLE or at the vent near V17

Turning OFF HR3 after purging:

1. Press the Emergency Stop and right after that close V17 (Flow on FI01 will be zero)

     2. Close SVSAMPLE

     3. Close VHSV and the rotatable valve on top of the line

     4. Close Vmup

     5. Close the bottle

Purging the He returning line from HR3 to the tank:

1. Close V14
2. Open MV102
3. Slowly open V17
4. After purging some He from the line, keep V17 opened slightly to have a flow and connect a purity meter to the vent

After purging: 

1. Close V17 
2. Close MV102

Purging the He inlet line from the tank to HR3:

1. Close MV103
2. Purge from MV101
3. Connect a oil pump to the buffer tank
4. Connect He bottle to Helium purge Inlet
5. Open the He bottle to 10 psig
6. Open the valve on the buffer tank and start vaccum
7. Monitor the pressure on the buffer tank and let it go up to ~ 0.2 psi
8. Close Vfill and pump the lines and monitor the buffer tank pressure to go up to 0.2 psig
9. Pump back the lines by opening Vfill and monitor the buffer tank pressure to go up to ~ 10 psi
10. Do the pump and purging for 3 cycles

Steps for pump and purge:

1. Close the hand valve from the pump
2. Set the He gas cylinder to 10 psig
3. Open VFill slightly
4. Open the yellow color hand valve L7B while watching the gauge
5. Once it's pressuresized (check pressure from the pump) close Vfill and L7B
6. Close VBTv on the buffer tank
7. Disconnect the line from the pump and connect to the purity meter
8. Crack open VBTv and check the purity