I *think* I figured it out... although I'll post some pictures below too...Take a look at the first picture on this page:http://www.pge.com/myhome/edusafety/gaselectricsafety/turnga...My "pipe 12" is coming out of the opening on the regulator that, on that picture, is just open to the air. Is that just a vent of some kind? Which would be why in the outdoor pictures it's open, but in my basement it's hooked to another pipe which vents outdoors?You can actually see on the second picture on that page ("Cabinet Meter") how in that one, that opening on the regular there has a pipe coming off of it.Anyway, without futher ado, here are pictures:http://mysite.verizon.net/vzeo1wyn/sitebuildercontent/sitebu...http://mysite.verizon.net/vzeo1wyn/sitebuildercontent/sitebu...If what I've said above happens to be right, then my only concern is that the valve is extremely difficult to turn. I did manage to do it, but it takes most of my strength. I admit I'm not the strongest guy in the world, but my wife would never be able to turn it, which concerns me. I was still not able to find any house-side valve on the meter or anywhere else.