How Did they get the air out in 1963?

JUGHNE

......This was supposed to be on the Main Wall.....
I have a boiler of that age that I just cleaned up. The state boiler inspector gave the boiler his blessing today.
It had been drained and sat idle for one season. Thankfully only one pipe froze. The building boiler room is on grade. The piping goes up into the attic. and drops down to commercial BB convectors. I have seen no air bleed ports in the attic. There are no isolation valves on the S&R--2 1/2" copper lines. No air bleeders on the convectors that I can see. They are actually the low point of the system so I assume the air is in the attic piping.

We have the larger 3-piece B&G on the return pumping into the lower boiler tapping, water fill is connected between pump & boiler.
The supply comes out the top side tapping thru a B&G ABFSO 4" X 4" with 3/4" up to ATF 18 Airtrol on compression tank bottom.
The horizontal line to the AFT 18 now has good slope up towards the tank.The pump is trying to move a lot of air.
I realize the best way would be to isolate the boiler and fast fill the system dumping the air/water. However there are no ports available to do this. This is thought to be needed for maybe two years until a new nursing home is built.

Somehow this system has worked since 1963, the air must have been purged somehow. I have another 1961 system piped the same way and have gotten the air out much quicker than this case. Any thoughts appreciated.

Gordy

Sure there is not at least a t with a plug you could crack open in the overhead piping?

JUGHNE

No, not sure, have been waiting for cooler weather. There is about 10" of blown in insulation covering things....plus air handlers, ductwork etc.
I have found only 3 of the 7 zone valves.....3 of the 7 have no power to the T-stat. One with no power did seem to heat up, the valve must be manually opened.

If nothing is found, any recommendations for drilling/tapping a port into 2 1/2" hard copper.....not sure if L or M.

Gordy

Petes plug?

hot_rod

A T drill is ideal for tapping into copper. Plenty of tube silver brazed into a drilled hole also.

kcopp

A properly piped standard compression tank does a remarkably good job at getting air out of a system. It may take some running time but it will work. Try getting the pressure up to 25 psi and let it run.....W/O the burner on.

JUGHNE

Thanks for all replies. Will get back there when the attic cools off. Will keep you posted.

Harvey Ramer

You can drill into the tube anywhere and braze in a copper stub. Properly done that will never fail.

JUGHNE

Do you think that "Stay Brite" soft solder would do the tap connection......trying to avoid the big torch in the attic.

I might try one in the bench vise in the shop.

Harvey Ramer

You don't use C-tanks for oxy-ace? I like those in a small holder to carry into attics. Along with a bucket of water and heat shields.

I have reservations about any type of soft solder. It is really hard to build enough of a bead to get more mating surface.

Gordy

I really think you need to just let it circulate. My radiant ceilings carry any air back to the tank no problem. My apartment has exact same situation as yours. Probably same era. 1 1/4" copper overhead 50' down to radiant floor manifold. Same deal. Air finds its way back to the tank.

JUGHNE

My hesitation on that is probably unfounded as the pump is below the water level of the system/boiler. I have to convince myself that the impellor will always be wet, even while pumping air/water mixture, there is little possibly of pump damage...yes?Each time the pump is switched off and restarted I hear more air being pushed into the boiler.

However there is the chance of having to drain the system for zone valve repair in the attic, perhaps several times.
Again, just fishing for ideas and appreciate any heads up points.
It is 40 miles away and I have been pretty spoiled having most of my work within a 3 mile radius.

Gordy

Well I'm sure on initial commissioning of the system there was some time involved, and maybe some choice vocabulary. However those were the times, and they dealt with it.

kcopp

Of course you could help things along w the ME trick.... A cup of dishwashing soap pumped into the system

JUGHNE

I have heard of that, but one should clarify if this is Dawn Liquid as you put into the sink for hand washing dishes......or Cascade crystals that actually go into the DW appliance.

When one son was about 10 years old he demonstrated what Dawn liquid does in the DW. It becomes a great foam machine!

Solid_Fuel_Man

I have had great luck pulling a vacuum on a dormant system with little water in it. It's my preferred way for most commissioning actually. New installs especially. Pull vacuum for a few hours after air testing for system tightness and the water will go into pretty much all the piping. This is of course after capping all the auto bleeders. Then run circulator on a cold system for a few hours/days.

Taylor

jumper

Solid_Fuel_Man said:

I have had great luck pulling a vacuum on a dormant system with little water in it. It's my preferred way for most commissioning actually. New installs especially. Pull vacuum for a few hours after air testing for system tightness and the water will go into pretty much all the piping. This is of course after capping all the auto bleeders. Then run circulator on a cold system for a few hours/days.



Taylor

Same here. You can go nuts bleeding air piecemeal.

JUGHNE

Thank you, Kcopp & Gordy, today I did run the pressure up to 25PSI and the pump did grab the air and pass it. I did run the boiler up to 150 just so I could feel pipes warming up.
Getting heat to most of the BB now,
I will try more tomorrow. It had to run about only about 3 hours before the water started to move.