Unrecognized return vent

mattmia2

just arrange them so any condensate flows back out the inlet.

109A_5

If you get the system air tight you probably won't need a vacuum pump. Just a means to let the air out of the system and not back in.

I was curious about the airflow through some of my one pipe vents so I built this interface. Sorry not Hoffmans but you get the idea.

pacoit

@Steamhead, @mattmia2 , Nice idea! However, my system doesn't have any steam traps to repurpose. Also, for the vacuum system, I envision a dry air-line return to a discharge pipe (with or without a pump); whatever I use as a valve to hold the vacuum, I don't expect it to see steam, or even more than warm air. So, I expect to use a check-valve or possibly a solenoid valve (depending on the ultimate design).

@109A_5, Excellent! That's a good way for me to quickly setup a vacuum system for testing.

By the way, I am in contact with @PMJ, who very kindly has offered to share his experiences.

Steamhead

@pacoit , they still make traps. For the long main you'd get a Barnes & Jones "Big Mouth".

pacoit

Thanks, @Steamhead .

FYI, the threads on the "L" of the Breck are 1/8" NPT.

EDIT: Also, it turns out the first Breck did not have a rusted out adjustment screw hole; it's just that the adjustment screw wasn't screwed in; once I obtained the key, I was able to screw it in without issue.—-Don't want people to think a Breck couldn't last 100+ years!

jumper

This thread is very interesting. Any steam heating system needs to expel air and return condensate to boiler. This system seemed to operate without radiator vents or steam traps which require maintenance.

pacoit

@jumper, Actually, it had (has) a thermostatic vent at each radiator return.

109A_5

@jumper Systems expel the air via the vent(s) (one pipe or two pipe), as you probably already know.

The boiler heats the water, the water expands into steam the air gets pushed out. When the thermostat is satisfied and the steam collapses back to water and a vacuum is formed. The trick is having the system tight enough so the air can't get back into the system (once expelled), to maintain the vacuum from cycle to cycle.

I believe if the system integrity is maintained the benefits are faster steam propagation (less air to push), less air (oxygen) minimizing corrosion and @PMJ's observation of more even, uniform heating.

I also believe with the faster steam propagation you may save some fuel too, since little gains add up over time. You are not burning fuel to push air (as much air) out of the system.

mattmia2

The breck is a bimetal element air vent. See Dan's article that he linked.