At last! Or... not quite!

If you had an oil fired boiler correctly sized you could install it with no LWCO, no Hartford, no pressure control and no burner primary control and no safety valve.

If nothing ever goes wrong it might run 100 years without an issue.

I have see steam boilers converted from coal that never had a lwco (don't know when they became mandatory)

I have also heard of a "technician" that removed an oil primary and ran the burner with no safety and nothing happened until another tech found it that way and corrected it. It ran that way for a year.

If the boiler is correctly sized you shouldn't need a pressure control either as it shouldn't build pressure so why need a safety valve?

But things do go wrong. Coal fired boilers had no LWCO or pressure control or thermostat or burner safety control. All they had was a safety valve and maybe a Hartford loop.

Many steam boiler don't have and don't need a Hartford loop if they have a boiler feed tank they are not required.

The most important reason for the equalizer and HL is to drain the header.

@ChrisJ

Not enough market share. Those of us in the NE in boiler country (or what's left of it) don't realize that most of the country is gas warm air or heat pumps. The steam boiler market is a replacement market unless its process steam or high pressure etc. Residential steam is a fraction of the market that drops every year as systems get scrapped for warm air or heat pumps or converted to HW. Look at the boiler mfgs for residential steam:

HB Smith…gone

Slant Finn…gone

That leaves

Utica Dunkirk

Burnham and clones Force, Crown etc

Weil McLain/Williamson

Peerless even they are slipping into the Burnham thing.

I don't buy shoelaces any more, I use 550 Paracord instead.

My laces break before the tips come off.

This reminded me of an old story. My boss at the oil company was loaded with $$$ but was cheap. I guess that why he was loaded.

We had a guy working there as an oil tech. He wasn't the best. There were 3 of us there at the time I was the oldest at 23 and the other two were 3 years younger. We all started at like $2.25/hour.

Because this guy wasn't so hot he hadn't had a raise in a while. One day he was walking past the owner's office to the shop out back.

Later the owner came to me and said "He has his work shoes taped together with duct tape, I guess I better give him a raise".

the header isn't right, the main should connect to a horizontal tee in the header then the end of the header should turn down to the equalizer. the horizontal tee where the main connects encourages any water to continue on to the equalizer. what you have now forces the water to turn when it hits the tee and it will tend to divide between the steam traveling up and gravity pulling it down to the equalizer.

You could just move the boiler 8" to get the piping just right

Looks to me if your are going to go with the pipe center it would be more than 2 inches. That 2 inches would be to the top of the pipe. I think the idea is the have that short horizontal section of pipe always submerged or full of water within the boiler's usable water level range. If steam can't get in there there won't be any water hammer.

OK, I can't fault you for that. Did you actually measure the 23-1/4" ? The water line in the boiler's drawing seems kind of high the way it is drawn.

I would have thought it would have been more like this.

When people know how to pipe there is no need to 'line things up".

the height of the Hartford loop shouldn’t matter (within reason).

I know the thought is out there that it can cause water hammer, but I don’t see how steam can get down there.

Maybe I’m missing something 🤷🏻‍♂️

This just may be Wye the manufacturers prefer a Wye but where can I get one in copper to fix my high Hartford Loop?

It absolutely does go there. What do you think would be there if not steam? Condensation is occurring virtually everywhere in a steam system. When steam condenses it occupies roughly 1/1,700th the volume. Steam flows in to take the place of that. It is the same way that radiators continuously get replenished by the boiler during the burner on time and up until the vent opens and there is a small pressure drop from the boiler to the radiator.

OK so do you think the entire header after the last supply and the rest of the equalizer remains full of air? Or does a gradual interaction occur that removes the air aided by the venturi effect of the steam rapidly flowing through the last supply remove that air? Why do you think hammer doesn't occur early in the cycle but tends to occur mid cycle?

air can't get out of the equalizer so no steam gets in, in a 1 pipe system. if the radiator doesn't vent no steam gets in. in a 2 pipe system if the equalizer ends up equalizing then it could push the air in to the return and get full of steam. in a gravity return 1 pipe system the mains and returns are connected so they can't get out of balance pressure wise. the equalizer will be hot because it is partially filled with the near boiling water in the boiler but it shouldn't have steam in it with a 1 pipe gravity return system.

@DanHolohan says:

"Steam rises up through the equalizer, just as it does through the boiler sections. When the relatively cool return water meets that steam at the close nipple, the rising steam bubbles quickly condense. Naturally, the return water rushes in to fill the void left by the collapsing bubbles, and this creates a slight water hammer inside the tee connecting the return to the equalizer."

EBEBRATT-Ed (who's been around forever) @EBEBRATT-Ed said it well: 'Steam goes down the equalizer until it hits water. The air rises up and goes out with the supply steam. If the equalizer stayed full of air it would be cooler and they are always steam hot."

The venturi idea was sort of my own and may be not the main effect here actually. But as the steam bubbles in the boiler can pass out through the return nipple into the equalizer they will naturally rise within that column, being lighter than the hot condensate and when they reach higher up and cooler strata they will implode, shrinking in volume and creating mild hammer which is probably inaudible. But this collapse in volume, along with the steam pressure in the header will cause steam to flow down towards the Hartford Loop within the equalizer displacing the air and pushing it out up through the header, into the main. This steam is also condensing which further pulls more steam in to make up for that.

Then later in the cycle, like mid cycle, you can get an audible hammer in that nipple of the Hartford Loop, if it is long enough to allow enough velocity from the acceleration, but it is again due to the implosion of trapped steam between water waves, and only if the water level in the equalizer is low enough.

Even if there is no problem mid cycle, there can also be late cycle water hammer in the Hartford Loop that can happen later in the cycle when the water level drops too low. From Dan:

"If [the water level] drops below the close nipple, steam will push down through the equalizer, enter the wet return and create water hammer. This usually happens near the end of the firing cycle, and it causes a very noticeable racket."

"Check to see if the water level in the boiler can drop to a point where steam gains access to the wet return through the boiler's equalizer. If it can, the steam will quickly push down into the wet return and create water hammer. This usually happens toward the end of the cycle."

Peerless Boilers:

"WATER HAMMER ON SHUTDOWN... CHECK THE HARTFORD LOOP. THE NIPPLE MAY BE TOO CLOSE TO THE BOILER WATER LEVEL. IT MUST BE 2 TO 4 INCHES BELOW."

From Dan:

"If [the water level] drops below the close nipple, steam will push down through the equalizer, enter the wet return and create water hammer. This usually happens near the end of the firing cycle, and it causes a very noticeable racket."

If this happens, then why doesn’t it happen when the water is above the nipple? Same steam supposedly in equalizer. Same water it comes into contact with. What’s the difference?