#915 ARCO Air Eliminator

elfie

have this old device that is leaking steam from top



would love to better understand this device and if anyone has any literature describing how it works and rationale for piping configuration



the steam system we have has not been operated very well (system pressure has been to high and is leaking 6-7 gals per day  - new boiler, installed 5 yrs ago, has a tank capacity of 44 gals).



its an old system that originally was heated with coal.  a vacuum system and radiators have no traps.

Enreynolds

We need

Some pictures, specifically of both ends of a radiator.  Just because it does not look like a trap does not mean it is not a device for keeping the steam in the radiator.  The fact that you are getting steam out of the air eliminator means you are passing steam into the returns.  This may be an orifice system that has had some orifice(s) removed. 

elfie

some pics of system

as requested here is a pic of radiators (dont believe they have been touched for 50 plus yrs and photo of boiler.



the boiler is operating at a higher pressure (about 5 psi) - probably should reduce pressure alot.



also attached is an end of line trap and a F&T trap at the end of a condensate return pipe.



the air eliminator is attached to a separate condensate return line.



we have knowledge that an older boiler did use coal many many yrs ago





thanks

Steamhead

That might be

an Arco Model K system. This was an Orifice Vapor system that had adjustable orifices built into the radiator valves, and could run at less than 1 pound of boiler pressure.



If your valves have little hexagonal caps on the front or back, at right angles to the radiator union connection, it's a Model K.



If the valves have been replaced, they will still need orifices. The orifices are sized as to only allow as much steam to pass into the radiator, as the radiator can condense. This kept the steam out of the dry returns- the same job a radiator trap does, but with no moving parts.



The easiest way is to get disk orifices from a company called Tunstall Associates, and drill them out to the proper sizes.



In the pic with the two Float-and-Thermostatic traps, the one on the left looks original. Does it have a name on it?



The one on the right looks like it was cut into the drip (drain pipe) from the dry (overhead) return. I bet they did that because of the pressure being too high or because of missing orifices, which allowed steam to enter the dry return. Does the boiler have a condensate tank and pump?



Here's a thread about a Model K we worked on:



http://www.heatinghelp.com/forum-thread/131004/ARCO-Model-K-system-in-the-Jersey-Skylands

elfie

yes there is a cond return pump

yes there is a condensate return pump with a trap (per pic); not sure when it was installed; its in a pit by boiler



there is an underground condensate return pipe relating to about half of radiators



vent pipe is venting continuous steam



trap by pump may not be working



thanks

Steamhead

Is there any way

to run that system on gravity return, without the tank and pump? That would solve a lot of your problems. The Model K that I posted uses gravity return.



I think you need a Steam Man. Where are you located?

elfie

air eliminator

thanks for all the imput

i am looking for some info about how the air eliminator works and whether it can be converted to a trap along the cond return pipe since its leaky



thanks

Steamhead

The air eliminator

may not be at fault here. In a steam system, everything is connected to everything else, so a symptom at one location often has its cause elsewhere.



I think you have way too much pressure, or missing orifices, or both, that is filling the dry returns with steam. In general, dry returns are only supposed to have air and returning condensate in them- not steam. There were exceptions- the Kriebel system comes to mind- but the Model K was not one of them.



To fix this, we need to get back to the system's original design, peeling away the layers of changes that the knuckleheads have made.

Mike Kusiak_2

No equalizer?

Its a bit hard to tell from the photo, but it appears that there is no equalizer connected to the new welded header. The old header above may have had one originally, but where it once might have been connected is plugged.

elfie

equalizer is on back side of boiler

hi,

equalizer piping on backside of boiler - see pic



also, a few months ago they moved the return connection to a lower point on the boiler header drip connection pipe - there is a condensate pump but i thought this was a bad idea (masking tape on corner edge of boiler is the water line

Abracadabra

hartford loop?

not sure, but I don't see a hartford loop.

elfie

hartford loop removed

oddly, hartford loop was removed

elfie

how does ARCO air eliminator work?

i see the thermostatic trap on top.



is there a float in the reservoir? and why is there another pipe going vertical alongside it?



if its non fixable, how can it be replaced?



thanks

elfie

end of line trap

some additional info about the system



the nuts on all radiator valves are all hexagonal  - so it seems original system may have been an Arco Model K system



one end of line trap has an ARCO 911 trap (amrican Radiator) (are rebuild kits available?)



there are two steam headers - does it make sense that one header ends with an ARCO F&T and maybe the other ends with an ARCO air eliminator (which i guess is connected to one of the header's dry return)



not sure if introduction of a condensate pump in a trench below floor by boiler that connects to an underground condensate return line prevents system from becoming a vacuum system



is it worth getting this system back to its vacuum state? needs a new air eliminator relating to one of the two headers, the other steam header seems to end. i would have to see the system butchered with a bunch of F&T traps



thanks