adding traps to a two pipe system

Dan C.

I looked at a job the other day that has 8 two pipe radiators and 1 one pipe radiator.  The returns all tie in to a common dry return with no traps, loop seals, or any other provision to keep steam out of the returns.  The solution I have is to add traps to each radiator, plug the vents, and vent the main large enough to handle the whole system.  The radiators are fed in the bottom and out the bottom.  Can I still use a trap if they are fed that way?  Most of the time that I see two pipe systems with traps they are fed through the top and return through the bottom.  Thanks

Steamhead

That will work

but inlet valve orifices would work as well and would not introduce another maintenance item. Make sure you have enough "B" dimension between the return and the waterline.  And keep the pressure down.



You can get orifices from Tunstall.

The Steam Whisperer (Formerly Boilerpro)

Me thinks its time to do some homework

There are tons of two pipe steam systems that operate without traps.  I'd take a close look at the valves and any other devices on the system for manufacturer's names.  Have you actually opened up an original supply valve to look for an orifice or opened up the return elbow to see that it really it just an elbow?   I just installed a new boiler on a two pipe system with no traps (see "A Sweet Little install" on the main wall)  and it works just fine.    These systems usually require a little digging to find out just how they were supposed to work.    I am now advertising trap elimination programs for two pipe systems as I continue to work on upgrading existing steam systems to high efficiency steam systems.  Dan's Lost  Art and later Companion really can be helpful.  Also Google searches with a manufacturers name will often bring up info from sources like the Smithsonian.

Jamie Hall

There is even a remote chance

that the system is even older -- there were a few "two pipe" steam systems in the very early days which were really sort of one pipe systems.  They had vents on the radiators, but the usual tell-tale is that they had valves (usually) on both the "inlet" and the "return".  They're in Lost Art...

Dan C.

Maybe

I really don't think that is the case.  It looks like someone just came in and totally destroyed this system at a later date.  They only have valves on the supplies.  i think it may have been some type of vapor system at one point but all of the valves have been changed but one.  The one that hasn't been changed looks like it may have some type of orifice in it.  It's the really old style that I have seen on a lot of vapor systems

Dan C.

Maybe

I really don't think that is the case.  It looks like someone just came in and totally destroyed this system at a later date.  They only have valves on the supplies.  i think it may have been some type of vapor system at one point but all of the valves have been changed but one.  The one that hasn't been changed looks like it may have some type of orifice in it.  It's the really old style that I have seen on a lot of vapor systems

Unknown

Orifices

Hi- Here's a good article on orifices and info on adjustable orifice valves which might be of help to you.

- Rod