Copper Or Steel To Replace Wet Return ?

SteamHeat

Copper Or Steel To Replace Wet Return ?

 

I know this has been asked before, but the only thread I

could find on it is from 2006 and did not seem to reach a definitive

conclusion. Maybe there is none ?

 

I replaced my old steam boiler last year and my pro suggested

this year that I replace my 70+ yr old rotting and sludge filled steel wet return that is

0.5 inches above the basement floor. It seems like a good idea.

 

Should I replace the wet return with Black Steel or with

Copper ( grade M or L or K ) ?

 

I would like the new installation to last as long as possible, so that I am not faced with re-doing the same work when I am much older and on a fixed income.



If I use K Grade Copper the inner diameter would be 0.05

inches smaller. Does this matter ?



If I use Copper should I ask my pro to use dielectric fittings where meeting up with Steel.



My dry return is about 2 ft. of steel NPS 2 inch.

 

There is a Bell Reducer and then about 5 ft. of vertical steel

NPS 1 inch.

 

There are 6 elbows and 2 couplers and about 48.75 ft of

steel NPS 1 inch just above the floor snaking its way all the way to the loop riser.

 

The loop riser is about 1.25 ft of steel NPS 1 inch. After

the next El there is about 1.33 ft of steel NPS 1 inch and a Union into a Tee

where I have Full Port Ball Valves setup so that the return line can be flushed

to a bucket without having to go into the Hartford Loop (and Boiler).

 

My pro says he can put a Tee and Full Port Ball Valve just

after the Dry Return Bell Reducer with a Garden Hose Fitting so that I can hookup a fresh

water hose from time to time to flush the wet return into a bucket to get all the anerobic bio sludge out.

 

Can I have my pro elevate the wet return run by 4 inches so that

I can fit insulation on the pipes and still have a little room to be able to get a mop

underneath it when we clean the floor ?

 

What pitch should we use for the return line or is level

acceptible ?



My boiler is a Weil McLain EG-50 Steam.

 

Thanks for all helpful suggestions.

Jamie Hall

Whichever

Copper is just fine for wet returns; I'd use K, but it really doesn't matter.  Or you could use black iron, but it's often easier to use copper.



Myself I wouldn't worry too much about the small difference in diameter.  In fact, I wouldn't worry at all.



I also wouldn't worry much about dielectric unions...



You can raise it up some -- but you really don't have to insulate a wet return, so that may not be an issue.  But level really isn't acceptable; it should have a slight pitch back to the boiler -- or wherever you have a drain arrangement (which is a good idea) for flushing it out.

SteamHeat

Pitch ?

Thanks Jamie.



Is the 1 inch down for every 20 feet of pipe run figure enough ?



I have a parallel flow / gravity single pipe setup.



Thanks.

Jamie Hall

Should be...

the actual slope of a wet return is of interest only when you are draining it or lushing it.

Ron Jr._3

I agree with Jamie

We've been using copper for returns for a few decades . Crap just does not stick to the inner walls as it does to steel . I wouldn't be too concerned about pitch to the boiler . Just install a purge valve after the Hartford Loop and you can steam clean the returns periodically . A full 3/4 ball valve and hose connector is ideal for the flushing .  

SteamHeat

Any Minimum Length For A Loop Riser ?

Thanks guys. I appreciate the information.



Is there a limit on how short the loop riser could be ?  I'm asking because if I have my pro elevates the return line to enable getting a floor mop underneath it once in a while, I do not want to shorten the loop riser beyond any technical requirement for proper operation.



Thanks again.

Ron Jr._3

Should be no problem

piping it high enough to get a mop underneath . The return can be as high as you want , as long as it slopes down from the end of the steam main and you drop it to the floor once it's near the boiler .

Charlie from wmass

just want to add

as long as it does not come up to the point where it can allow a cross over between drops if you have multiple returns or leave section dry when water levels drop while boiler is running. I prefer using iron pipe for returns as I do not like soldering pipe that has been used for steam systems. The iron I can cut and thread later or if rotted I can replace it. Copper may be less cost effective when you get to larger diameters and you get to thicker wall thicknesses such as 2" K vs. 2" IPS.

SteamHeat

A Few More Questions Copper vs. Black Steel.

Thank you for your replies.



Ron Jr.

"...and you drop it to the floor once it's near the boiler ."



Would being two inches off the floor at the elbow feeding the loop riser be a problem?



Charlie from wmass

"...if you have multiple returns..."



My system has a single return line.



"I prefer using iron pipe for returns as I do not like soldering pipe that has been used for steam systems."



Is your concern regarding the copper and tin getting into the water and contaminating the block or is the concern the mechanics of the pipe manipulation for dissassembly and reassembly while doing the repair?



Thanks everyone for all of the helpful information.

Charlie from wmass

I have found

when copper has been in service I find it refuses to take tinning and if repairs or tie ins are needed it is difficult to work with the pipe. If a pipe is in the traffic path iron is more difficult to damage.

SteamHeat

Very Salient Points !

These are significant considerations that had not even occurred to me.



Thank you for bringing them to my attention.



Now I really have to try to anticipate how clumsy we will be as we grow older. :-)



Oh boy.