[Dsg-rtpc] Gas panel

[Carlos Ayerbe Gayoso]

Hallo Sebastian


  1.  Please find attached a couple of pictures I took yesterday. I'll take more later.
  2.  besides keeping the DMS side open to the atmosphere, the instructions of bypass the DMS are written (as Jiwan and Madhu did yesterday).
  3.  CV1 is indeed a backflow preventer (is in the list of components of the panel) and it was a piece always part of the gas panel scheme, not a last minute incorporation. It is connected before to the DMS bubbler, which will be filled with oil as the other bubblers. I guess there was a reason to have it.
  4.  Those pressure meters were a last minute incorporation and they are supposed to be redundant information for the tests. The one you indicate was changed yesterday afternoon.
  5.  so you want to measure the pressure before and after the buffer volume? because PT3 is supposed to measure the differential pressure buffer/atmosphere (and it was your suggestion). PI2 is a pressure indicator  before the flowmeter TO the buffer volume.

George is now in the loop.

Cheers

-Carlos
________________________________
From: Kuhn, Sebastian E. <skuhn at odu.edu>
Sent: Tuesday, June 11, 2019 2:26 PM
To: POUDEL, JIWAN; Carlos Ayerbe Gayoso; Hattawy, Mohammad; POKHREL, MADHUSUDHAN
Cc: DZBENSKI, NATHAN M.
Subject: Gas panel

Dear all,

I have a couple of questions/comments about our wonderful gas panel:

1) Can someone take a high-quality picture of the actual panel as it is right now and send/post it?
2) For now, we would like the “DMS circuit” to be just a simple loop, open to the surrounding air, and not connected in any way to the RTPC loop. The easiest would be to disconnect the “pressure sensor” cable from the T (the blue tubing connected to PT2 on the “DMS Press Port” side). That way, Pt2 will also measure the pressure difference between RTPC and atmosphere (we have to be careful to stay within 0.5 Torr or 1 cm = 0.4” of water of atmospheric pressure inside the RTPC). We should operate the gas panel in “DMS bypass mode” until we have an actual DMS - that means opening MV4 and closing MV3 and MV5.
3) Jiwan and I noticed a device labeled “CV1” on the exhaust line of the DMS. I guess this is a backflow preventer (requiring 1 psi to open)? I don’t think that’s a good idea - we will never want the pressure in the DMS to exceed 1 psi! Can we remove it and instead put the bubbler in use as for the other exhaust circuits? (that means it has to be filled with oil)
4) Right now we have several visual pressure meters (very nice!!!). One of them, unfortunately, has much too high range - I believe it’s the one that is reading the RTPC pressure. We’ll want this to have the same scale as the others (tiny fractions of 1” of water column). [BTW, it would be nice if the drawings could be updated to show these pressure meters!]
5) Right now, we do NOT have a pressure indicator on the 4He bag (“buffer volume”). That is an unfortunate oversight (probably my fault). I know that the bubbler will do in a pinch (by ensuring that the pressure is only slightly above atmosphere), but it would be nice to have a transducer or at least a visual pressure meter on the “To Buffer” line as a backup. (If it is not too much to ask…)

Thanks - Sebastian
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mailman.jlab.org/pipermail/dsg-rtpc/attachments/20190611/e33abf5f/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 20190610_111526.jpg
Type: image/jpeg
Size: 1535983 bytes
Desc: 20190610_111526.jpg
URL: <https://mailman.jlab.org/pipermail/dsg-rtpc/attachments/20190611/e33abf5f/attachment-0003.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 20190610_111510.jpg
Type: image/jpeg
Size: 1441229 bytes
Desc: 20190610_111510.jpg
URL: <https://mailman.jlab.org/pipermail/dsg-rtpc/attachments/20190611/e33abf5f/attachment-0004.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 20190610_111508.jpg
Type: image/jpeg
Size: 1375396 bytes
Desc: 20190610_111508.jpg
URL: <https://mailman.jlab.org/pipermail/dsg-rtpc/attachments/20190611/e33abf5f/attachment-0005.jpg>