Reconnecting radiator with black pipe connections

Hello,

I've just finished tiling my kitchen. There are two previously capped off black iron pipes coming up through the tile. My plan was to reconnect the radiator (which had been removed by the previous owner). I'm not sure how to handle this problem, though: the tile has raised the floor about 3/4", so the one pipe is now too short for the cast-iron radiator. The other is, for some reason a few inches shorter and barely protrudes from the tile (I cut the tile around it out a little more to allow for some kind of union. What can I use to make up the 3/4" on the one side? For the shorter side, I bought a union with a tapered-seat joint and a variety of lengths to make up the distance, but again, matching the height exactly seems almost impossible. Should I be using PEX instead? Or brass reducing bush to copper to elbow to RH/LH nipple to radiator? Should I avoid these dissimilar metals to avoid a galvanic reaction?

Kind of a convoluted situation; appreciate any advice. Thanks,

John

You could try cutting down the legs on the radiator. Have you tried prying the pipes up a bit. They may have slipped down during renovation

You can use a extension coupling. They may be hard to find.
http://www.homefixitparts.com/showp...at=galvanized Pipe Fittings&subcat=Extensions

John

Thank you for the suggestions. I'll see if I can source an extension coupling. Lots of custom work in an old house like this...

OK, googled "extension coupling," which brought me to "street coupling," which brought me to a few other forums where there were unhappy people with the same problem. Street coupling would work for the short side, anyway.

http://www.bicwarehouse.com/red-bra..._campaign=1609763&utm_source=Affiliate&aff=cj

Will I have "galvanic reaction" problems if I put a piece of brass in between the black steel pipe? (I've heard using galvanized is a no-no.) Closed system, so oxygen gets used up and corrosion stops, right?

Normally, you will connect the radiator to the pipes with a "union valve" on the feed side and a "union return elbow" on the other end, thus you do NOT need any other unions.