Pumping the DSSC Chamber

The original documentation can be found in the Alfresco Document Library.

Evacuation

Step 1:

The last entry about evacuating the DSSC in Elog.

1. The DSSC chambers are in air
2. The gate valves to the turbo pumps are closed
3. the two full metal valves are closed, the manual one and the automatic one (VV1 in karabo scene)
4. close the by-pass manual valve to speed up the pumping
5. close fully the RVC300 for pumping down (press Edit to be able to do fine tuning of the flow)
6. vent the section behind the full metal valves connected to the DSSC by disconnecting one KF connection before the full metal valve.
7. open slowly the manual full metal valve (the valve near the dssc that needs to be opened with a tool) in this way we equilibrate the pressure in the DSSC and behind the gate valve in case there is any pressure difference (there should not be since I have vented but just in case). -> Careful: When closing the chamber, there might be pressure differences of several tens of milibars depending on the weather! In case no valve has been left open, do this step very carefully!
8. open the automatic full metal valve VV1 (the other full metal valve attached to DSSC)
9. switch on the scroll pump
10. open the RV2 valve above the scroll pump
11. open the manual valve that brings rough vacuum to the pumping section
12. open the valve that brings rough vacuum to the turbo pumps and leave it open

Step 2:

start pumping, bringing rough vacuum to DSSC chambers

13. slowly open the RVC300 to start pumping
14. once RVC300 is fully open, open slowly the bypass manual valve
15. once the bypass manual valve is also fully open, wait a bit for pressure to equalize in the chamber and before the turbo gate valves

Step 3:

start turbo pumps

16. open the valves of the turbo, the pressure will not change
17. close the full metal valves, the manual one and the automatic one (disconnect the cable of the automatic one so that it cannot be open by mistake)
18. close the manual valve going to the RVC300 for pumping
19. close the bypass valve
20. close the RVC300 for pumping
21. start the turbo pumps
22. wait for them to run at 100%

Old

Old comments??:

Pumping down DSSC chamber and Pipe section

1. Let’s assume the system is in air
2. Close the gate valves in front of the turbo pumps
3. Start the scroll pump
4. Start the two turbo pumps
5. Open fully the full metal valves going to the pump cart
6. Start with the RVC closed
7. Start the scroll of the pump cart (is it possible to start only the scroll pump of the pump cart?)
8. Open the RVC in order to have a pumping rate of 1 mbar/sec
9. Start the turbo of the pump cart
10. Once the pressure is below e-3 mbar, open the gate valves to the turbo pumps
11. Close the full metal valves

Check list: what is needed

• 1x full metal valves
• 1x full range pressure gauges
• 1x vatterfly valves in front of the turbo pumps
• 1x TCP 300 (controller is already in rack room)
• 1x venting valve for TCP 300 (How to connect the N2 line?)
• 1x venting valve for TCP 700
• 2x adaptor CF40 – KF40 (from full metal valves to KF bellows)
• 1x T piece KF40
• 3x bellows KF40
• 1x adaptor KF40 – KF16
• 1x adaptor CF40 – KF16
• 1x T piece for bellows to scroll
• 1x cross KF for pirani and hand valve for leak test
• 1x pirani
• 1x pneumatic valve for scroll in front of hand valve from pre-vacuum beamline
• Prepare filter dummy!

1. The system is in vacuum, turbo venting valves are closed and vatterfly gate valves are open
2. close manual rough vacuum valve to leak tester
3. open fully RVC300 valve to venting
4. close valve to turbo rough vacuum shortly
5. Evacuate the region between turbo venting valves and RVC closed using a scroll pump (keep it pumping)
6. open the rough vacuum valve to the turbo
7. keep both the valve to turbo rough vacuum and venting setup open
8. Settings of turbo, Vent enable ‘ON’, Vent mode ‘0’ (automatic venting), Vent freq ‘80%’ (percentage of the final rotation frequency)
9. Before switching off the turbo P_8_rough_vacuum = 8.4e-2 mbar, P_pipe =1.6 e-3 mbar, P_DSSC = 3.5 e-4 mbar
10. Switch off the turbo pumps and wait for the rotation speed to go below the set value, 80 % for example
11. Once the venting valves are open I can close completely the RVC 300
12. close the rough vacuum line to the venting
13. fill the line with N2 (make sure the overpressure valve is there)
14. start opening the RVC 300
15. when the turbo are runnig at few % and the pressure in the chambers is in the e-2 mbar and comparable to the rough vacuum pressure, I need to close the rough valve to the scroll pump, so that I can start the actual venting
16. Open venting valves, and vacuum will go to e-2 mbar
17. Close valve to scroll for evacuating region behind venting valves
18. Start to slowly open the RVC for venting use a rate of 1 mbar per second
19. Once the pressure is in 1000 mbar, close the turbo venting valves
20. close valve to rough vacuum of turbo
21. fully open the RVC for venting
22. open valve to evacuate the venting line
23. open the venting valves, the chamber will see vacuum
24. close the RVC for venting
25. close valve to between scroll and venting line
26. fill line with N2
27. open slowly the RVC to 5 e+1 to have 1 mbar / sec at the beginnig

Check list

• 2x venting valves for turbo
• Pipes from venting valves to manifold
• 1x Y manifold
• 2x adaptors swegelok to KF16 (1x from T to manifold, 1x from RVC to N2 line)
• 1x KF 16 T piece: 1x to manifold, 1x to scroll for evacuation of line, 1x to RVC
• 1x hand valve from T piece to scroll