4 1/2" fittings on steam main.

baj702

I need to replace a section of the steam main, and it appears to be 4 1/2". Does anyone know where I can get fittings for that size? I can find 4" and 5" fittings, but I haven't been able to find anyone who carries 4 1/2".

Steamhead

Those will be difficult if not impossible to find. Is the main 4-1/2" for its entire length, or does it reduce at some point?

baj702

@Steamhead the main starts out at 5", so somewhere there is a 5" to 4 1/2" reducer, but it might not be very accessible (I need to go look for it today). The section that needs to be replaced is 4 1/2" and eventually gets down to 2", but because a lot of the radiators have been taken off line since the building was built, I can safely go to 3" for the replacement. I just need to hook onto the 4 1/2" pipe somehow to get it down to 3".

Steamhead

I wouldn't drop it down that low. The resistance to steam flow and accompanying pressure drop increases with the length of the main, so you still want to keep it as low as you can. I was going to suggest that you stay at 5" to be safe, but you could probably get away with dropping to 4" now with the lesser load. Going to 3" might mean not enough steam gets to the end radiators. Post the radiation count and the distances of each pipe size to be sure.

baj702

@Steamhead (in transit) Thanks for the help! So, I found a 4 1/2" to 4" eccentric reducer about 10' from the access hole in the tunnel where the steam main is. This is part of the main that needs to be replaced, so I was able to harvest that reducer. It took a couple of hours to get the pipes out cleanly, but it looks to be in really good condition. Right at the access hole, there is a 4 1/2 coupling, and if I can cut that off, I'll have a a 4 1/2" pipe with threads that I can then connect the 4 1/2" to 4" reducer to. Once I'm at 4" I'm back into normal territory. That coupling is on pretty good though. We spent a couple of hours today trying to get it loose, but no go. Hopefully tomorrow we'll be able to free it.

The whole building is only about 2000 EDR, and I've got about 300 EDR to pick on the other side of the 4 1/2 to 4 reducer. Max length of pipe is less than 100' after the reducer.

baj702

@Steamhead The above comment is to you... I selected the wrong username from the list...

Steamhead

And if that doesn't work out, I'm sure someone out there has a 5"x4" eccentric reducer.

ScottSecor

Not that you want to go this route, but I think that both 5" and 4" schedule 40 steel pipe could be welded to the outside or inside of 4-1/2" pipe. It's been years since we've done it, but I'm pretty sure the 4-1/2" pipe fits neatly inside the 5" and the 4" pipe fits nicely inside the 4-1/2" pipe.

That being said, I'm guessing welding pipe is not a feasible option in your situation.

GBart

Welder