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May 10, 2008

Replacing Below Ground Wet Return Sections

I have sections of the wet return from my boiler that are below grade and have corroded. I am having them replaced and I have a few questions.

1) I have excavated the area in preparation for the plumber and plan on repairing the floor once the plumber is done. The existing pipe was buried in dirt and covered in a few inches of concrete. Now that I have a chance to do the job right, I am wondering what the best way of covering the new pipe will be. Should it be wrapped in some way before covering it to avoid corrosion? Should I cover it with dirt or gravel or a combination of both prior to laying the concrete over it? Any tips on doing this job right would be appreciated.

2) There is currently no way to flush the returns. Should I ask the plumber to install some sort of flush valve before it goes underground? Again, I just want to make sure that the job is done right so I don't have to revisit it.

Thanks for your help...

Comments

1. What type of pipe is going back in the ground? If copper, make sure you're using Type L (or K) -not M, and only below the boiler's water line. I would protect the pipe with ArmaFlex or some other foam rubber insulation. If you're replacing steel w/ steel -I probably wouldn't do anything - look how long your old piping lasted.
If your pipes run along the perimeter, why bury them at all? Why not strap them along the base of the perimeter wall?

2. You are supposed to have a full-port valve on the return side of the hartford loop, and drain valves at both ends of the wet return for just such a purpose.

Posted by: guest at May 11, 2008 8:53 AM

The entire wet return is made of steel, so I would assume thats what he will put back. MOst of the wet return is indeed above ground and in good shape. This section is burried since it is in front of a door and would be a trip hazzard.