Repairing leak in 2" steam return line pipe running along basement floor

When I had a new steam boiler installed (3300 sq ft, 3 story house) several years ago, the plumbers replaced the low return lines with copper. These are the low lines at floor level (floor that the boiler sits on!) that normally always have water in them rather than steam. I believe they used 1 inch copper, possibly 1.25" I can't measure it right now as I no longer live at that house. It works fine. Your building may have a bigger system and maby not be able to use the smaller pipe.
There are no stupid questions, but there are lots of stupid answers.

Larry Wasserman - Baltimore Maryland - lwasserm(a)sdf. lonestar. org
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file
Upload is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.