Getting geared up to work a huge medical gas shut down this evening at a local hospital. We have to shut down 7 floors of medical air, oxygen,and vacumm. Putting eveybody that needs it on reserve bottles and posting them up at each room. 4 hr deadline. I enjoy doing medical gas cause its clean.The nitrogen purge keeps the copper brand new even after silver soldering.... looking forward to it. Anybody else certified to run gas?