The "equalizer" is mis-named. It does nothing to equalize anything.

ethicalpaul

yeah that’s the myth. Everyone just repeats it because that’s what they read somewhere but nobody ever tested it.

Henry Gifford knew it was false and probably a few other people

STEAM DOCTOR

Just taking a guess over here. There are probably systems where there is not much of a pressure drop between the boiler and the end of the main. Well piped, smaller system, with nice clean water in the boiler... Probably not much of a pressure drop. But take a larger boiler, that might be running at higher pressure than it really should, with a very long main, that might be undersized, with wet Steam which contributes to pressure drops, and there might be a significant pressure difference between the boiler and the far end of the main. Which would certainly lead to water being pushed out of the boiler. To accommodate all systems and scenarios, the A dimension probably became the industry standard. Just a guess

ethicalpaul

Well it never hurt anyone, for sure. But I'd pay $100 to see any residential system that had more than 1" of water column between the boiler and the end of the main.

EBEBRATT-Ed

@109A_5

Bringing the return line into the boiler at the height of the Hartford loop connection won't work. If in the rare occurrence a return line leaked the water would syphon out of the boiler. You need the header drip to break the syphon.

techforlife

If memory serves me, I believe the Hartford insurance co. came up with the Loop and Equalizer (anti syphon) before there were any LWCOs. Maybe also because one cannot just turn off a coal fire. They found a way to keep most of the water in the boiler primarily for safety reasons.

109A_5

https://forum.heatinghelp.com/discussion/comment/1846148#Comment_1846148

Not my design, apparently a method they experimented with long ago. Although once the boiler water line dropped below the tapping height the siphon would stop (no dip tube inside the boiler). Likewise without the equalizer connected to or at the top of the Hartford loop horizontal pipe the wet return would siphon the boiler almost dry or at least to the level of the leak of the wet return (whichever lets the air in first to break the siphon).

Depending on how you read the article it seems to imply the equalizer is part of the Hartford loop assembly. Which it is needed to provide a vacuum break to stop the siphon.

With the Gifford loop the horizontal portion or connection is high enough that there won't be a siphon.

ChrisJ

Perhaps that's where the name equalizer comes from.

It equalizes the negative pressure when the pipe breaks so it "vents" the loop and stops it from siphoning from the boiler. It never had anything to do with equalizing positive pressure when the system is intact and never actually does anything to a properly functioning system.

I've brought that up a few times, but didn't think the name had anything to do with it until now.

ScottSecor

@ethicalpaul I am sure you have posted the details of your current steam system. I recall you have a Peerless 63 gas steam boiler. Just for reference, please share some details of your system (again) so I can get some perspective. Like others, I am thinking about and trying to visualize what is going on.

How many radiators do you have heating your house?

How many rooms are in your house?

What diameter and how long are your steam main(s)?

Do you have any other source of heat besides this steam boiler?

I believe your main(s) are well insulated, is this correct?

Are your steam mains in heated space?

I apologize for all of the questions in advance.

Thank you,

Scott

ethicalpaul

I have 7 radiators, 9 rooms depending on how you count, my single main is 2" for about 20' and then 1.5" for another 20'. It's my only source of heat used in the winter. My main is pretty completely insulated. My main is in unheated basement.

EdTheHeaterMan

https://forum.heatinghelp.com/discussion/comment/1846396#Comment_1846396

And when you finish the first page of that application @ethicalpaul, page 2 needs

Social Security number

current address

previous address for the last 25 years

names of all you children

Your mother's madden name

at least 5 of your most used passwords (especially your debit card PIN)

annual income

marital status

and your dog's name.

ethicalpaul

The best way to see what I am saying about the equalizer is to watch my 27 minute video. I'll have to watch it again to make sure I didn't say anything crazy but I think it's pretty good.

One interesting thing is when I started the video, I was still under the impression that there would be a noticeable pressure drop from the start of the main to the end. But residential steam is too slow and too small for it to be enough to let the water level rise at the far end of the main. You can see me figure this out during the video.

In the video below I have pressure gauges hooked up as well as a sight glass at the far end of the main to monitor the water line movement (there isn't any).

This is why I keep saying "Dimension A is a myth". Don't feel bad, even Peerless still thinks it's a "thing". Peerless says there's a 1/2 psi of pressure differential at the end of the main (hence why you need dimension A). But it's false, at least in residential low-pressure steam (to include multi-family buildings too).

Peerless also thinks there is another 6 inches due to friction loss through the return line, which is complete fallacy in my experience. And 8 inches for cold start-up condensate load, which is a load of BS because the condensate at all times is exactly the same. The boiler is making X steam per minute regardless of startup or otherwise. Ignore the drawing below, it's make-believe.

https://youtu.be/6ZLg3fqU1MQ