OT Gas System Hardware

Phone numbers

Person CERN Mobile Extension Home office
LHC gas group piquet +41 76487 2516 162516  
DSS piquet +41 76487 3051 163051  
Sebastian Bachmann +41 76487 2038 162038 +49 6221 5419404
Iuri Bagaturia +41 76487 1804 161804  
Stefan Haider +41 76487 0256 160256  
Steven Pavis +41 76487 0929 160929  
Frederic Merlet +41 7647 4089 164089  

Gas System Schematics

This is a simplified sketch of the gas system covering the main aspects. A more complete version can be found in EDMS 827973. GasSchematics.png

PCs for the gas system

See here: Gas System Infrastructure (in online TWiki)

Check-list for gas system parameters

Log onto gasts01w:

To display the parameter names click on the rightmost of the crosses at the top right of the display

Panel Subpanel 1 Subpanel 2 Parameter Allowed Range Last value Checked by
        from 22.07.2009 from 30.07.2009 Sebastian
OT     Ratio 1 69,8% - 70,2% 70%  
OT     Ratio 2 0% 0%  
OT     Ratio 3 69,8% - 70,2% 30%  
Mixer     TotalFlowAS 1350-1650l/h 1500l/h  
Distribution Rack 61   PT6122 3,5 - 4,0mbar 3,8%  
Distribution Rack 61   PT6124 1,5 - 2,0mbar 1,9%  
Distribution Rack 61   PT6125 0,2 - 0,6mbar 0,4%  
Distribution Rack 61 Flows Input Flow F-Modules 45-55l/h ~50l/h  
Distribution Rack 61 Flows Input Flow s-Modules 25-35l/h ~30l/h  
Distribution Rack 61 Flows Gas loss <30% <25%  
Distribution Rack 62   PT6222 2,6 - 3,1mbar 2,8%  
Distribution Rack 62   PT6224 1,4 - 1,8mbar 1,6%  
Distribution Rack 62   PT6225 0,1 - 0,5mbar 0,3%  
Distribution Rack 62 Flows Input Flow F-Modules 40-50l/h ~43l/h  
Distribution Rack 62 Flows Input Flow s-Modules 15-25l/h ~20l/h  
Distribution Rack 62 Flows Gas loss <30% <10%  

The OT gas system - at UXA A2(?) gas platform

The oxygen measuring devices - 1a is not working correctly, instead we use 1b (in the online panel- auxiliary, Backup gas1, then the value is divided by 10 )

The OT gas system - mixer and purifier

The OT backup gas system

Currently there is one battery of premix (Ar/CO2/O2) at about 60 bar connected, and then a second battery as the backup to that, also premix Ar/CO2/O2 at 80 bar. One of the batteries can be seen on the pictures below. One of the batteries can provide up to 1-2 days of gas.

There is a description of the gas on the battery panel itself (fig.4a ) but to avoid confusion you might want to check the gas description paper(fig.4b) hanging on one side in a plastic pocket.

Should the first battery become empty it will require a manual intervention (simply just pulling on a lever on the changeover panel - see fig.2) to change to the backup supply being as the changeover panel is not automatic.

As a further level of backup, there is the CO2 purge supply which can be brought on line in the UXA A3 gas platform simply by closing the pre-mix valve and opening the CO2 valve.

Main Gas Pump

The main gas pump sucks the gas through the OT and pushes it back up to the surface. It sits in UXA, third floor, in the last gas rack.

It is a membrane pump. Its membrane needs to be changed regularly by the gas group. The maximum lifetime is 2400h. During the change the OT is flushed from the backup gas system. The flow through the gas monitoring stops while the gas system is stopped, that's way the gains drop. The intervention needs 30 minutes downstairs, and about 2h for the monitoring gains to recover. During all of this, OT HV needs to be off. To be on the safe side, we require at least 10h of time.

These pictures were taken during the membrane change of May 11th, 2012. The membrane was in for ~2400h and looks badly worn out.

pump.jpg open_pump.jpg membrane_new.jpg membrane.jpg membrane2.jpg

Useful links

Topic attachments
I Attachment History Action Size Date Who Comment
PNGpng GasSchematics.png r1 manage 121.2 K 2012-07-10 - 12:22 TillMoritzKarbach  
JPEGjpg IMG_0281.JPG r2 r1 manage 178.2 K 2012-05-11 - 19:07 MoritzKarbach The oxygen measuring device - now not working correctly
JPEGjpg IMG_0282.jpg r2 r1 manage 231.8 K 2012-05-11 - 19:07 MoritzKarbach The oxygen measuring device
JPEGjpg IMG_0283.jpg r2 r1 manage 245.4 K 2012-05-11 - 19:07 MoritzKarbach The handle to manually switch from gas mixture to purging the OT with CO2
JPEGjpg IMG_0286.jpg r2 r1 manage 423.5 K 2012-05-11 - 19:08 MoritzKarbach OT Gas mixer
JPEGjpg IMG_0287.jpg r2 r1 manage 450.0 K 2012-05-11 - 19:08 MoritzKarbach OT gas purifier
JPEGjpg IMG_0289.jpg r2 r1 manage 224.4 K 2012-05-11 - 19:08 MoritzKarbach The backup gas battery
JPEGjpg IMG_0290.jpg r2 r1 manage 230.9 K 2012-05-11 - 19:09 MoritzKarbach The label on the OT backup gas battery
JPEGjpg IMG_0291.jpg r2 r1 manage 182.3 K 2012-05-11 - 19:09 MoritzKarbach The content description of the OT backup gas battery
JPEGjpg IMG_0292.jpg r2 r1 manage 228.4 K 2012-05-11 - 19:09 MoritzKarbach The handle to manually switch from backup gas 1 to backup gas 2
JPEGjpg membrane.jpg r1 manage 449.0 K 2012-05-11 - 18:58 MoritzKarbach  
JPEGjpg membrane2.jpg r1 manage 527.7 K 2012-05-11 - 18:58 MoritzKarbach  
JPEGjpg membrane_new.jpg r1 manage 457.1 K 2012-05-11 - 18:59 MoritzKarbach  
JPEGjpg open_pump.jpg r1 manage 506.2 K 2012-05-11 - 18:59 MoritzKarbach  
JPEGjpg pump.jpg r1 manage 511.0 K 2012-05-11 - 19:00 MoritzKarbach  
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Topic revision: r12 - 2012-07-10 - PaulSeyfert
 
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