best material for wet return?

jpf321

I believe my current wet return is Galvanized 1-1/4" .. is that the best material these days for wet return? Can Pex, Glass, Copper or BIP be used? I'm just wondering. Thanks.

nicholas bonham-carter

wet return material

there does seem to be a bias against using any galvanised pipe in steam piping, and i don't know why. i would think that wet return lines would benefit from the anti-rust properties. perhaps there will be other views on this.

once again "if it ain't broke........................................."--nbc

Unknown

Wet Return

When I replaced mine I did it in copper. I arranged the piping so that it wouldn't bind (get stuck between to hard points) and had room for expansion. Doing it in copper I think is better as it is less likely to get "crudded up".   I designed in several ball valves and a water hose hookup so that I can segregate the wet return and flush it out. I have a valve high on the dry return (on the vertical before it becomes the wet return)  and a Wye fitting where I can attach a fitting for a garden hose.  On the boiler end I have a full port drain valve with a hose connection. There is a ball valve on the pipe going up to join the Hartford Loop.  To flush I hook up the garden hose at the wye and another hose at the drain . Makes the job very easy.  I'm not even sure I need the flushing setup as the wet return in the 3 years since it has been installed has remained remarkably clean. Unless there is a real reason to do so I'd just replace your present wet return. Trying to clean the old one is a thankless messy job and you may find even then can not be done very satisfactorily

Edit: I might mention if you have to go underground it's a whole different program, I'd personally avoid a buried return if at all possible though I realize with a finished basement this may not be practical - Rod.

BTW: Thanks for the piping chart.  Don't know whether you have found this one yet: " 500 Plain Answers to Direct Questions of Steam,Hot Water,Vapor and Vacuum".......By Alfred Grant King 1915 It's a Google Book

[url=http://books.google.com/books?id=1WMJAAAAIAAJ&dq=500+plain+answers+to+direct+questions+on+steam,+hot+water,+vapor+and+vacuum+...++By+Alfred+Grant+King&printsec=frontcover&source=bl&ots=pzTFCaI_L5&sig=bY6caQy96Ljy3C9WkqCFwLExumE&hl=en&ei=ywkvS4CbEpT0sQPv2uzPBA&sa=X&oi=book_result&ct=result&resnum=1&ved=0CAgQ6AEwAA#v=onepage&q=&f=false]http://books.google.com/books?id=1WMJAAAAIAAJ&dq=500+plain+answers+to+direct+questions+on+steam,+hot+water,+vapor+and+vacuum+...++By+Alfred+Grant+King&printsec=frontcover&source=bl&ots=pzTFCaI_L5&sig=bY6caQy96Ljy3C9WkqCFwLExumE&hl=en&ei=ywkvS4CbEpT0sQPv2uzPBA&sa=X&oi=book_result&ct=result&resnum=1&ved=0CAgQ6AEwAA#v=onepage&q=&f=false



Link is good straight to the book,

Joe V_2

Black iron or copper

Over a relatively short period of time, galvanized pipe will rot and leak.  In my experience, with my old house, galvanized pipe made terrible water supply and drains.   Plus, if you work on one segment of corroded pipe, you inevitably create a crack in a pipe somewhere else.  They do well as chain link fence posts though!

jpf321

Thanks and ...

Rod --



Thanks for the book link .. I'll have a look .. I had found another book along the same lines .. in reading it I thought that "this is The Wall 100 years ago." .. we've come a long way baby!



Steam Heating Problems; or Questions, Answers and Descriptions Relating to Steam Heating and Steam Fitting, From The Staionary Engineer c. 1889 (PDF)

jpf321

pictures rod?

Rod --



Would you be able to post some pictures of the valves, bibs, wyes and how you linked into your dry returns and boiler end? I'd much appreciate it.



Thanks.

jpf321

copper type?

I see "M", "L", Rigid .. is there a difference btwn them except for price? 

Unknown

Copper for Wet Return

Here's a good link on copper pipe.

http://www.copper.org/publications/pub_list/pdf/copper_tube_handbook.pdf

I keep a copy on my computer for reference. Check Page 9 "Heating". "L" is thicker than "M". Sorry I can't provide pictures at the moment as we're 3000 miles away visiting our kids for Christmas.  I can draw up something on my computer and post it. It's really nothing complicated.  - Rod

jpf321

Type L copper...

is suggested on Pg. 9 of the above link from Rod for "condensate return lines" .. fantastic Rod .. you come through again .. did I mention backing up your "Steam Reference Directory" :-)



No need to trouble yourself too much with the drawings or pictures .. enjoy your Holidays and your Kids!



Thanks

jpf321

last 2 ft???

On pg. 13 of the document posted by Rod .. I quote:

Steam-Heating Return Lines— For steam-heating systems, especially return lines, the outstanding corrosion resistance and non-rusting characteristics of copper tube assure trouble-free service and maintenance of traps, valves and other devices. On condensate and hot water return lines, it is recommended that the last two feet before the heating medium should be double the size of the rest of the line. For example, if the return line is 1-inch tube, enlarge it to 2-inch.



Can anyone explain why the recommendation is to have the last 2 ft double size?



Thanks.

Unknown

Last 2 feet.

I'm not sure what the reason is for this though I imagine that has something to do with thermal shock and the differences of expansion between cooper and cast iron.  The doubling of the pipe diameter would have the same affect on condensate as it has with steam in that is slows the velocity down and would allow the incoming cool condensate to mix with the hotter boiler water.  The affect on the pipe would be going from cool water to warmer water to hot water over the 2 foot length.  If you ran the pipe all the way to the boiler at the same diameter you would have cool water /cool pipe suddenly transitioning to hot water /hot pipe right at the sweat adapter fitting attached to the boiler casting. 

On residential steam systems the transition of copper to black iron is done away from the boiler where the two materials would be the same temperature.  Example:- the return is done in the same diameter pipe but the last couple of feet is done in black pipe and the Hartford Loop in done in black pipe. In this case quite often a bronze ball valve joins the two on the uptake to the elbow /close nipple of the Hartford Loop.   You'll also see the equalizer pipe done in copper and also the return pipe entering it, while the header and the pipe entering the boiler, are black pipe.  You have to keep in mind that this book was written by "copper men" who had to come up with a solution to this problem so one could use copper all the way into the boiler and not that nasty stuff, (shudder) BLACK PIPE!

- Rod

jpf321

makes sense

doubling of the diam. makes sense to allow a velocity decrease and an even heat exchange of fluids. thanks.