Observations on my old, rotted out wet return.

Hap_Hazzard

The first place to fail was, naturally, at one of the joints, because the threads are cut halfway into the pipe, creating a weak point. When I inspected the rest of the return, I found that it was badly rusted in places where it had been painted with ordinary house paint. The paint was loose and flaking, and when I scraped it away, I could see deep pits in the pipe. I have some theories about why this happened, but it's just speculation. My solution was to run dry returns until just before the boiler, and piping the underwater leg in copper like most of the pros seem to do.

tcassano87

you have pictures of the lines that are rotted out?

Jamie Hall

There is a potential problem with your solution: if there is more than one drip from a steam main into that wet return, or if you have real dry returns and they dripped into that wet return, you have created some potentially problematic alternate paths for steam flow.

Intplm.

What's your speculation. Was the pipe rotting from the inside out or from the outside? I have seen both. Bet you have too.

mattmia2

you aren't really saving anything with black iron vs copper anymore. There was a time when steel was much cheaper but it is about a wash now.

RTW

Copper? is that really what the professionals of today. I thought the Dead Men never used copper in steam piping mains and returns and preferred black iron/steel

Im all ears on this comment

Regards,

RTW

ethicalpaul

Copper is fine below the water line simply because there's no negative for it there, and there is a good reason to use it, its corrosion-resistance.

The dead men were just men

Jamie Hall

Copper below the water line. Easier. Quicker.