Hallway Light Box

[SFBadger]

I own a 1912 Edwardian in San Francisco. I am in the process of putting in a new light fixture in my hallway. When I took down the old fixture, there was a 4" pipe coming down through the middle of the box, which will be in the way of the base of the new fixture. Here is a picture:
http://dc-loomis.com/photos/hallway-light.jpg

Someone told me that this might be pipe for an old gas fixture, but I kind of doubt it becuase there are electrical conduits coming into it now, but I thought it's better to be safe than sorry. Is this pipe safe to remove? If so, any idea how it comes out? The screw with the green arrow goes into wood. The screws with the red arrows attach the box to the pipe, but do not allow the box to be removed.

[HayZee518]

that pipe is a gas pipe. the fitting is called a hickey. check out your gas system and see if it is connected somewhere. slowly remove the hickey and sniff. if you smell gas. retighten it and look for another location for your light.

[SFBadger]

Thanks, glad I asked.

OK, I removed the cap on the end of the pipe and it is filled with a cement-like material. I could not budge the pipe itself, when I applied moderate force. I was a little bit nervous about breaking something, and not being able to stop a gas leak, if it is still "live."

I'll try to trace the gas lines and see if I can rule out any flow to the old fixtures.

Any other advice?

[HayZee518]

I worked for a contractor back in 1965 and we ran into several houses with the 3/8" pipe for gas lights. I can only remember one house that the gas line was still active. The box is a cast iron box with clamps for the knob and tube type wire. The center knock out was removed allowing the pipe to come through, the box is fastened to a stud or a board with a hole in it. the pipe goes through the board and box into an elbow in the ceiling joist space above the plate. I can't figure out why a contractor would use a box with a gas pipe IF the gas fixture was alive. Maybe the box was an after thought when the knob and tube was installed. the "hickey" was used with the electric fixture and 1/8th inch pipe because the pullchain part was also 1/8th inch and just screwed together. the wires were fixture wires - cotton over jute or rubber and just fit through the 1/8th inch pipe. splices were made to the knob n tube in the box and an escutheon plate was put over this.

[SFBadger]

Interesting. I came across the same pipes in the living room and dining room, when I replaced the old chandeliers. The pipes had caps on the end with rings for the chandeliers to hang from. Since I replaced those fixtures with different chandeliers, I didn't give the pipes a second thought.

I'm not sure what you're referencing when you mention 3/8" and 1/8" pipe. My pipe is at least 1/2" outside diameter.

[HayZee518]

the 3/8" npt has about a 1/2" O.D. - regular 1/2" npt is 7/8" diameter. the small diameter fixture tube is a 1/8" straight pipe thread. you can buy these in hardware stores as fixture parts. the hickeys can be had with all sorts of pipe threads and fixture studs.