Vapor system vent replacement question.

tmw

I have an Arco Model K system ("Lost Art..p.269) with one central "air eliminator" that has 2 ports.One trap (ball valve) has been frozen in the closed position.The other trap (thermostatic) in the open postion.  My system has been running a pressure of 4-5psi. The system rapid-cycled, or just plain cut off if the pressure was any less.



I removed the old ball-float valve (see pic) and ran the vent open for a day. The system stopped rapid-cycling and performed well at about 8oz (the pressures are all relative as I have no idea of the accuracy of the old 30psi gauge). Problem was that the open vent spewed steam (and didn't stop) about ten minutes after burner kicked in..So I added a Gorton #2 (see pic) and system now runs at about 2-3 psi with normal cycling.. The #2 blows quite a bit of hot air, so I'm guessing I should add one or two more?



There is another vent coming from a 2nd port in the "air eliminator" that is stuck in the open position. please see pic.



The boiler is a 40-45 y.o Weil McClain 1.85GPH. I have about 70-80' of 2" mains.



The three basement radiators (house is a bank barn foundation, so unfortunately kitchen and family room are in the basement) have never worked although they are pitched correctly and the risers get hot. System has been neglected for decades and I doubt the wet returns have ever been cleaned.





Questions:

What type of vent can I purchase to replace the thermostatic one pictured?



Can I extend the piping that  I just added (see pic) another 12" to add another Gorton#2 on a tee? and how much pitch do I need on the new vent piping to insure that condensate will flow back? I'm thinking very very little, like 1-2 degrees?



If I need to build a "menorah" type of manifold for more vents up there, can I drill and tap the other (non-piped) side of my old air eliminator as I don't have enough headroom on that side to come out the top.. This would place one arm of the menorah about 3-4" lower than the other..



thanks

Steamhead

The second "vent"

is a thermostatic radiator trap. Does the pipe coming out from the side of this unit go to the steam main? 

tmw

No...

 it dumps into the return.

Charlie from wmass

Just a thought.

What about removing the trap and installing a Menorah off that tee? and capping the pipe that leaves the trap. I may be missing some of the engineering behind this system. Time to go look up Model K. Vapor systems are rare as hen teeth in my immediate area.  

tmw

I've already got 2 ft. of 1/2" ..

with one Gorton #2. I could stick another vent on that piece, then pipe out the other side of that old box and add more vents. Then I could pull out the old trap, plug the box and cap the pipe that dumps into the return. I just have no idea of whether this is a good or bad idea..

Steamhead

That's pretty strange

is there any connection at all between the steam main and dry return? 

tmw

yeah, I think...

there's this pipe that comes off the header and to the dry return. it looks like someone put copper below the waterline.   outside of the near piping, the ends of the mains connect to the returns





sorry. it looks like that pipe dumps directly into the wet return...

tmw

I'm assuming

that you're talking about the pipe coming from the mouth of the thermostatic trap and not the 2 ft of 1/2" pipe I added for the Gorton?

tmw

so I added a 2nd Gorton #2

and the pressure came down to about 1-1.5 lbs. I'm going to experiment and add a 3rd one tomorrow. I also will be installing a low pressure gauge and NOS mercury vaporstat tomorrow.



Does anyone have any thoughts on what that thermostatic trap is doing hooked up to the return. And should I just replace it, and if so with what? Steamhead?

Steamhead

It may have been

to keep steam from escaping if the pressure got high enough to get past the orifices. I believe the pipe that runs down from that air eliminator, tees into the vertical return pipe below the boiler's waterline, correct? 

tmw

actually no....

the pipe from the air eliminator tees into the vertical return above the waterline.  In terms of vertical distance  it's about 1 inch above the upper valve of the sight glass assembly. 



Your thoughts? Should I replace this thing?

Steamhead

Maybe

refresh my memory, are you running a Vaporstat? If so, and it's set properly, the steam shouldn't reach that far........



That pipe probably did connect to the vertical return below the waterline when the original boiler was in place. Older boilers usually had higher waterlines than newer ones. What we need to know is whether it makes a difference in this case.



I'm still up for a trip to Joisey, if needed.....................

Charlie from wmass

It may have been there

Frank with the old boiler. The present boiler may have a much lower water line than is required for the system to work as first installed?

tmw

I'm putting in a vaporstat tomorrow,

along with a low pressure gauge. I'll see how things play out now that I have 3 Gorton #2's up there. And yes, I think a trip to joisey is in your future. There are a number of problems that a pro needs to address eg. blocked returns, wet steam, etc.



Despite the neglect this poor old system has seen, it still heats the house and is SILENT. I'm amazed that I have no water hammer.....