Can the low-volt wiring to a generator annunciator panel pass through the same junction box (without a partition) containing low-volt wiring corresponding to medical gas valves, gauges, and controls in a hospital?

I do not know, but I would ask myself this as a quick test to say no. Is the system that I plan on mixing with a critical system. If it were I would not ask any further. My opinion here is not worth anything, but I noticed you were on rright now and that no one had responded.

I have to agree with sabrown. I can't put a specific article on it. It's best to stay away from the critical system.

Is this a 517.30(C)(1) thing? What is the generator doing?

Greg:
IMHO, to provide an answer of allowed or not, a lot more details would have to be provided by the OP. He mentioned 'critical system', gas valves, control and no specific area for the 'j' box. I'm curious if he has any plans/specs. for the install.

I don't know if Ann. wires come into this but read .
700.9 (B) p. 1108 2008 handbook & (D)3 page 1112 2008 nec code handbook.

Yoopersup

Medical gases are oxygen, nitrogen oxide, and oxygen. They are piped to many rooms in a hospital. Gauges read their pressures and go into alarm when not within spec. I never mentioned "critical systems" but of coarse the most important purpose of the generator in a hospital is to provide critical and emergency power when called upon to do so. Generator annunciator wiring is not circuit wiring. Both the med-gas and generator wires I am describing are for status indicating only. The conductors feeding the gas valves I mentioned before are actually fed separately.

On the face of it,
I would say no.
Make life easier for yourself and just run a seperate conduit.
At least then there will be no question of your stuff mucking up anything that has been pre-installed.
Even though we are talking about low-level signalling stuff here, its best to have some sort of segregation, even if for fault-finding purposes down the track.
By that I mean, who hasn't opened up a but of wire troughing and found a tonne of wires all the same colour?

Also with new conduit, you have the opportunity to identify your work as being say "GEN-ANN" along the way.

Just my thoughts.