Questions about improper header efficiency, cracking top of boiler, and hartford loop

midiman143

Hello everyone,

Thank you in advance for sharing your knowledge and experience. I recently had a no heat situation that was caused by a clogged pigtail/ pressuretrol. They cleaned out pigtail and got it working again but I was told my boiler has MAJOR issues with the header piping and the hartford loop. I live in the northshore of Boston and I had the following questions I hope I can get some opinions on

1. I know the header is not supposed to be copper and maybe not 1 pipe. If it was piped correctly with black steel, 2 pipes, and probably a few inches higher would I save a ton of money. I was told the steam is very wet and I am wasting a TON of money because so much fuel is being burned. Could a repipe actually save say more then 5-10%?
2. I also have some small amounts of water coming from the top of the glass water gauge down when it is firing and was told is is not good and an indicator that the boiling is very turbulant and could actually cause the top of the boiler to crack from the water splashing onto the top of the boiler I guess. I find this hard to believe but is this true?
3. I was also told the hardford loop was installed incorrectly, and is affecting the operation of the system. I am under the impression that the hardford loop is a safety feature to keep water in the boiler when a leak occurs and the system loses water and not would affect the normal operation of the boiler. Am I naïve ?
4. The back of my boiler has a screw pipe fitting that is capped off near the top of the boiler. I was told this is the skimming port and should not be capped off. Is this true?
5. The technicians (Chilli Willi) who came out did talk about going to one of Dans seminars 2 years ago and are supposedly one of the best steam professionals in Boston. I am finding it hard to believe that a repipe would save me anything close to the multi thousand dollar repipe or would extend the life of the boiler. Is there any truth to this?

Thank you!

EdTheHeaterMan

As far as the Hartford loop, we need to see the other side of the boiler.



The wet steam thing may not be an issue because the copper pipe looks large enough and tall enough, Does the system operate and heat evenly and with relatively low noise? I don't think repiping will save you 10% on operating.

Of course. most of the steam pros here would not have piped it that way and definitely used steel pipe and iron fittings. but there is a difference of opinions between the manufacturers and the professionals. its an ongoing discussion. I personally would use steel with iron fittings.

midiman143

@EdTheHeaterMan thanks for the reply. Once i get back home i will get a photo of the Hartford loop.i just wanted to get the conversation started in the meantime. 

As for your questions, the system works great i think. No noise, and it does heat evenly. We bought the house piped this way so what can you do right? I'm finally getting around to insulating the pipes this season.

Jamie Hall

If it ain't broke, don't fix it.

Yes, the header piping isn't good. But you know that. If it's not banging and no vents spitting water, leave it. You'll not say enough on the change to make it even remotely worth while.

The leak if it's outside at the top of the sight glass probably indicates that the o-ring there is shot That would not be a surprise. It's not hard to repair -- but it does mean taking the sight glass out, and they are fragile. I'd wait on that until spring. If it's water coming up and over from inside, it does indicate that the boiling is more turbulent than it really should be -- and that the boiler needs skimming. That's what the capped opening is for. Did someone really tell you that it shouldn't be capped? What did they want it closed off with, then?

And as to the water splashing and hitting the top of the boiler and cracking it... um. Nice try. Whoever you were talking to may call themselves one of the best steam people in Boston, but that doesn't speak very well about steam people in Boston (there is at least one I can recommend, but I'm not sure he gets around to the north shore)(and it isn't the one you had).

Can't speak to the Hartford Loop without seeing it.

And do take the price out --quite right, not allowed.

midiman143

@Jamie Hall Thank you for the reply and just to clarify the site class is not leaking it's just that water will come from the top of it and dribble down inside the glass and was told that not normal. Like you said maybe it's a sign that it needs to be skimmed.

 It sounded like they wanted to attach something to that capped end which would make it easier for skimming but I didn't really understand what would be attached and how it would make it easier than just having a cap there. They did say for the price they would run the boiler crazy high for like 3 hours to skim it. 

EBEBRATT-Ed

@madiman143

Most of what the contractor told you has some truth in it

1. The header isn't piped by the book
2. Hartford loop ...we can't see it
3. The skim tapping is only opened to skim the boiler. Some put a valve on it and some just cap it when they are done. Either way is fine.
4. Water coming into the top of the sight glass means the water level is unsteady: Skimming may fix this. If skimming does not fix it then it may require a re pipe.

5. Water splashing will not crack the boiler.

By Dan's book the lost art of steam heat available on this site


What I would do. If it's running ok NO knocking. no banging heating ok leave it alone at least until the cold weather subsides.

Then in the spring come back here and we can tell you how to skim the boiler. There are probably some U tube videos you can watch in the mean time.

We can't talk price here but that is a fairly easy re pipe

midiman143

@EBEBRATT-Ed Thank you for the reply. Great advice. I need to brush up on the lost art of steam heating. I read it about 5 years ago and have lost some of it for sure. I was thinking of skimming the boiler sooner then later, is there a reason you say to do it after season vs sooner? I did a search briefly on yoututbe and didnt see a ton and started searching on here and found a few post about it but I would assume someone has written a proper write up about it. I will also take a photo and upload it tomorrow of the hartford loop to get everyones 2 cents on it.

Jamie Hall

The reason you won't see much about skimming is that it is so darn simple, if you have a skim port. Bring the boiler up to a simmer -- no more -- and raise the water level slowly until there is just a thin stream of water coming out of the skim port. Keep it simmering -- don't let it boil, and keep the water level up there until I get tired. A couple of hours anyway. Then adjust the water level back to where it belongs, cap the port, and you're good to go.

EBEBRATT-Ed

@midiman143

If you have the LAOSH there is a chapter in the back that tells you how to skim. @DanHolohan's method is the one I use.

You can skim any time. I was just concerned about getting a plug or cap off mid winter and having issues if it's never been off before

midiman143

@EBEBRATT-Ed @Jamie Hall @EdTheHeaterMan Here are the photos guys and the cap I was referring to on the back that I assume is used for skimming. Thanks for the tip as well on where to find the skimming method in the book!

EdTheHeaterMan

It is possible that the Hartford Loop is incorrect. Difficult to tell from the pictures however it is easy to determine with a tape measure. Assuming the floor is level (or within a 1/2" of level) measure from the center line of the short horizontal nipple to the floor,(about 26" see diagram) then measure the distance of the water line indicated on the boiler (@ about 28" from floor see diagram) The Close Horizontal pipe nipple should be about 2" lower than the water line.

Another item on this diagram indicates that both supply openings should be used, but if the system is operating adequately, then I'm not sure there is a problem that needs to be fixed.

If however, you find the short connecting pipe nipple is too low, and you are going to get that corrected, then you might as well do the rest of the piping correctly. look at this video for best piping practices https://www.youtube.com/watch?v=L11ywcjSOFA

You may not get a lower operating cost, but the boiler will last longer. That is a savings worth thinking about

PS. There is one problem with the manufacturer figure 7 diagram, no swing joints on the riser to header connection. That is explained in the video.
If you do not have the original install/operation manual here is a link to one that is close to your system https://uticaboilers.com/sites/default/files/240012155_SFEV_IOM-Rev D.pdf

midiman143

@EdTheHeaterMan Thank you so much for the reply and work you put into finding all this information. I watched the video and found it very informative as well. When you say there is no swing joints in the diagram, is that the same as saying there are no threaded 90 degree elbows? From my google search it seems like a swing joint needs 2 elbows to allow rotation and movement. One for vertical movement and one offset 90 degrees to allow for horizontal movement. Is that correct?

I did take your advice and measure the hartford loop, and your suspicion is correct. Instead of 2" below the water line it is 6.5". I understand that this means the water in the return side can leak/drain to 6.5" below the water line but in reality how does this affect the system? The returns come from the ceiling down next to the boiler run for less then a foot and then rise up to the hartford loop. If i understand the point of the hartford loop correctly, I would have to have a hole in either the 2 return lines to have this incorrectly installed loop come into play correct?

You mentioned this would help the boiler last longer, could you explain more about that or where I can read/watch more information about this?

Thank you again so much for all the help!

EdTheHeaterMan

midiman143 said:

When you say there is no swing joints in the diagram, is that the same as saying there are no threaded 90 degree elbows?

A swing joint allows for lateral movement as a result of expansion of metal in this diagram there are no swing joints so there is additional stress on the cast iron


In this illustration there 4 elbows to arrive at a destination where clearly only 2 elbows are necessary.


The additional 2 elbows are considered a swing joint. minor expansion and contraction will e absorbed by the movement of the threads of the steel pipe in the cast iron elbows.

midiman143 said:

I did take your advice and measure the hartford loop, and your suspicion is correct. Instead of 2" below the water line it is 6.5". I understand that this means the water in the return side can leak/drain to 6.5" below the water line but in reality how does this affect the system?

The Hartford loop keeps the boiler from running dry resulting from excess steam pressure buildup in the boiler and forcing the water backwards out the bottom of the boiler into the return pipe If there was 3 PSI of steam in the boiler that could push water up the return pipe into the first floor radiators 8 PSI can push it to the second floor radiators. By having the header connected to the return via the equalizer pipe, the same pressure that is forcing the water out the bottom of the boiler is also the same pressure that will push the water back in the bottom of the equalizer into the bottom of the boiler. Once you understand that... now connect the return pipe to the equalizer at a point about 2" below the water line... now the water must spill over the "Loop" to be pushed up the return pipe into the radiators. Water does not just go up by itself. it is heavier than steam, and the pressure that is pushing the water up is equalized at the point where the "Loop" is connected.

Another reason is, if the return pipe ever springs a leak, the boiler will only leak out water until it reaches the "Loop" then the water won't go up over the Loop and into the leaking return.

Now understand, the LWCO and the Pressure Control have both failed to turn off the burners when this happens. But in steam systems that happens more often than you might think.

midiman143 said:

You mentioned this would help the boiler last longer, could you explain more about that or where I can read/watch more information about this?

The video you just watched should explain this question. If a boiler fails... you need to replace it. If it does not fail, then it lasts longer.

ethicalpaul

Another reason is, if the return pipe ever springs a leak, the boiler will only leak out water until it reaches the "Loop" then the water won't go up over the Loop and into the leaking return.

But the boiler will keep boiling, sending out steam which goes to the return and leaks out. So the hartford loop delays the dry firing of your boiler for a little while, basically useless.

EdTheHeaterMan

ethicalpaul said:

Another reason is, if the return pipe ever springs a leak, the boiler will only leak out water until it reaches the "Loop" then the water won't go up over the Loop and into the leaking return.

But the boiler will keep boiling, sending out steam which goes to the return and leaks out. So the hartford loop delays the dry firing of your boiler for a little while, basically useless.

says the man who has that piping arrangement on his own boiler


But the Hartford boiler insurance company required that piping arrangement to get boiler insurance from them. And this useless piping arrangement drastically reduced the number of boiler explosions in the country. (that last statement was sarcasm Paul) But you are entitled to your opinion and we can choose to disagree.

ethicalpaul

I had to pipe it to pass my inspection, true. And I might have piped it anyway because it does make a nice separation between the return and the boiler for maintenance purposes.

and it probably keeps some rusty sludge from migrating to the boiler.

But I think you must know that its protection against boiler damage is non existent, possibly delaying dry firing for an hour or so. Do we really disagree? If so, no loss of respect on this end, thank you for the discussion!

BobC

Back when that loop became a requirement, boilers were a lot more hands on because most were coal fired. An extra hour was probably all many needed to realize something was wrong - the sharp decrease in deaths tells the tale.

Bob

ethicalpaul

But how would dry firing a boiler due to water loss cause an explosion? A fire I can see, but an explosion results from runaway high pressure with no or failed PRV. How does dry firing cause an explosion?

BobC

As far as i know explosions only occur when water is added to a very hot dry firing boiler like a control waking up and doing it's job AFTER the horse has left the barn or the boiler operator adding water to such a boiler. I'm not a heating pro but I've lived with and maintained boilers for my whole life. That added water flashes to steam and the rapid expansion is what causes mahem because the badly overheated cast iron or steel can't handle the pressure and then raw fuel is just dumped into the whole mess.

Before I bought the palace i now reside in I was reading the paper on a Sunday morning when i smelled something very hot. It was summer so the only reason for a boiler to be on was to satisfy the DHW coils need for heat. I carefully made my way downstairs and saw the landlords 40 year old Delco 4 section steam boiler had a large red spot and the baking paint was probably what i smelled. I went over and killed the electricity to the boiler and shut off the oil feed to shut everything down. I then went upstairs and called his daughter to tell them the boiler had failed but everything was now off and probably safe.

That boiler was replaced with a Burnham boiler the next week and i heard the landlords wife complaining that i should have just added some water and things would have been fine. The installer told her that would have probably caused an explosion and to be glad I acted as I did.

Bob

Jamie Hall

Two things here. First, the explosion possibility from dry firing is actually a two stage catastrophe. The first stage is the boiler metal cracks when the cold water is added. The second stage is when that crack releases the pressure -- if any -- in the boiler, and the entire contents flashes into steam, propelling odd bits in various directions at speed.

Second, on the Hartford loop. When it was introduced many boilers were at least partly open loop, if not entirely, and it was expected that much of the steam produced would never come back anyway. What was wanted was a way to get water into the boiler without a risk of a leak in that connection allowing the boiler to empty -- and the Hartford loop does that, if the feed water is connected before the Hartford Loop on a return connection, and not directly to the boiler.

ethicalpaul

BobC said:

As far as i know explosions only occur when water is added to a very hot dry firing boiler like a control waking up and doing it's job AFTER the horse has left the barn or the boiler operator adding water to such a boiler. I'm not a heating pro but I've lived with and maintained boilers for my whole life. That added water flashes to steam and the rapid expansion is what causes mahem because the badly overheated cast iron or steel can't handle the pressure and then raw fuel is just dumped into the whole mess.

Before I bought the palace i now reside in I was reading the paper on a Sunday morning when i smelled something very hot. It was summer so the only reason for a boiler to be on was to satisfy the DHW coils need for heat. I carefully made my way downstairs and saw the landlords 40 year old Delco 4 section steam boiler had a large red spot and the baking paint was probably what i smelled. I went over and killed the electricity to the boiler and shut off the oil feed to shut everything down. I then went upstairs and called his daughter to tell them the boiler had failed but everything was now off and probably safe.

That boiler was replaced with a Burnham boiler the next week and i heard the landlords wife complaining that i should have just added some water and things would have been fine. The installer told her that would have probably caused an explosion and to be glad I acted as I did.

Bob

Thanks for that story! That lines up with the few other cases of boiler failure that I've seen since I've been here (only 3 years):

- Boilers with Hartford loops lose water due to a leak somewhere.
- Boilers with Hartford loops dry fire
- Boilers with Hartford loops cause "hot smell" which is fortunately noticed by the homeowner
- Boilers with Hartford loops are an explosion risk if water is added when they are red hot
- Boilers with Hartford loops have to be replaced

So where in these storylines is the place where "Hartford loop saves boiler or family"? I just don't get it. The whole thing seems to be a case of mass illusion. I assume the boiler in your story above had a Hartford loop too.

SteamingatMohawk

Two sides to the debate:

Hartford loops are a figment of an insurance company’s imagination (mass illusion).

Hartford loops do provide a margin of safety for a certain type of problem.

To me, the stated purpose of the Hartford Loop (HL) was to prevent a coal fired boiler from losing water in the event of a leak in the condensate return line.

When it was created, boilers did not have low water cutoffs. They were invented a few years later.
They probably also didn’t have auto feeders.

Therefore, in the specific problem for which the HL was created it was a way to extend the time for the boiler to run out of steam and since coal fired boilers required frequent attention, it gave some margin to “finding” the problem between the leak starting and the boiler running out of water.

In a single pipe system, I believe an equalizer is key to the “balance” in the system, keeping the water level in the HL consistent with boiler water level. But may be something for another day.

As @ethicalpaul correctly implies by example, it is not a prevent –all for other problems. So what, does a HL have a legitimate function? What is the coal-fired boiler vintage history as to why it was created?

Interesting side point is that my auto feeder can operate on a LWCO signal. Theoretically, with a condensate return leak, the boiler could continue operating with the LWCO and auto feeder making up for the losses for a long time. It turns into a once through system.

This article on the Certified Commercial Property Inspectors Association enlightens the discussion.
https://ccpia.org/hartford-loop/

ethicalpaul

Just one of the weird, wrong things in that article:

Also, most steam boiler manufacturers now require that two-pipe systems be installed.

EdTheHeaterMan

ethicalpaul said:

So where in these storylines is the place where "Hartford loop saves boiler or family"? I just don't get it. The whole thing seems to be a case of mass illusion. I assume the boiler in your story above had a Hartford loop too.

I remember learning about the underwriters loop in the 1960s. I may be wrong but the memory I have is that boilers installed before the LOOP was introduced had check valves. the check valves failed and the boiler steam pressure could have enough force to push the water line down like this illustration.


If this is true, then could a boiler fail because the water level dropped and the weight of the water in the return was insufficient to keep the water in the boiler above the minimum lever required for safe operation.

By adding an equalizer and returning the water 2" below the water line, this boiler pressure thing would be eliminated by piping design. The Equalizer and the close nipple 2" below the water line is the Hartford Loop.

Even if @ethicalpaul disagrees with the return hight, the equalizer part of the Hartford loop is important in the design. So if there is anything to Paul's validity that the Hartford Loop is useless... it is only 1/2 useless. The equalizer makes sense to me. What are your thoughts on the equalizer Paul?

ethicalpaul

The Hartford loop is not the equalizer to my understanding. It seems like you are grouping them together to make the Hartford Loop more important.

I don't really see the benefit of the equalizer for pressure purposes. The pressure is roughly the same throughout the whole system, isn't it? The path from the main to the return seems like it would provide the same pressure-balancing to me.

The equalizer does provide a real nice path for carried-over water from the header to get back to the boiler. I could put a valve on mine and see if it does anything.

EdTheHeaterMan

@ethicalpaul, Hand fired steam boilers of the 1800s and early 1900s had large steam chests. There was very little problem with carry over water that needs a path back to the return. This is what I was told in the 1960s. Those concepts were and are still reinforced by the teachings of the great one ( @DanHolohan). Reference the first 30 seconds of this video https://www.youtube.com/watch?v=L11ywcjSOFA&t=3s

Those boilers were not equipped with equalizers in the near boiler piping. I remember learning about Dimension A in the boiler return piping. Many boilers were installed in a pit in the basement so the proper dimension A could be maintained in order to have enough static head pressure in the return to counteract the Boiler's Steam chest pressure. See previous diagram where 3 PSI requires a 7 ft. dimension A. When the Dead Men, back in the late 1800s, determined that 1.5 PSI was all the pressure needed, the dimension A could be reduced to 24" or 36" or something more easily designed. When the Insurance People required the equalizer and the close nipple pipe at 2" below the water line to get insurance, boiler failures were reduced exponentially.

The near boiler piping that put the return condensate water back into the boiler at the 2" below the normal water line at the added equalizer vertical pipe is what I always considered the Hartford Loop.




Paul, where do you believe the Hartford loop is actually located?

PS I took a heating class at a technical school in Philadelphia that had 30 old boilers in the basement that could actually heat the building. There were low pressure oil burners like Williams Oil O Matic, Timkin and Dynatherm, along with many High Pressure (100PSI) Gun burners like Quiet May and ARCO piggy-back.

The old man that taught me was really old when I was in my 20s. So i can say that i learned from a real Dead Man from back in the day. George Spence was in his 70s when i learned about dimension A on a steam boiler and how to clean a check valve on the return, because there were still uninsured boilers without equalizers. I even remember working on a coal fired boiler in one home in Old City Philadelphia.

ethicalpaul

I think of the hartford loop as the oval circled portion from your drawing. I can picture a hartford loop without an equalizer and vice versa. Is that right?

”boiler failures were reduced exponentially” I’d still like to understand how.

EdTheHeaterMan

Once upon a time in 1870 there was a boiler in a basement that heated a home. Every 3 hours the lady of the house would add 2 shovels of coal to the boiler to maintain the flame. Just before bedtime the lady of the home would add 6 shovels of coal and close the damper slightly because she did not want the fire to burn out overnight while she was sleeping. One evening, while stoking the fire for the evening there was a commotion outside the home, The Husband called the lady of the house to see what was happening. This happened just after the 6 shovels of coal were put in the boiler, but before the damper was adjusted to make sure the fire did not get too hot.

After the incident was over everyone retired to bed and over some time, the fire in the boiler increased and caused the steam pressure to rise above the normal 1 PSI pressure the system was comfortable with. Since the check valve on the condensate return was dirty, it stuck open and the pressure in the steam chest of the boiler forced the water level dangerously low causing a crack in a section to split open. The pressure drop in the boiler resulting from the crack allowed return water to rush back in to the boiler and the water flashed into steam when it hit the red hot metal of the already cracked boiler. This flash caused additional pressure, greater than the already fatigued metal could handle. There was a small explosion of steam that made a section of cast iron break off thru the asbestos insulation and hit the basement wall. there was a mark on the wall that was 1/2" deep.

Needless to say, the boiler would no longer produce heat and needed to be replaced. There were no injuries and the "Explosion" was never reported because there was no injuries and no other property damage. (other than the boiler failure)

When the replacement boiler was installed the home owner asked how to prevent this from happening again. The Installer read about an interesting new pipe design in a trade journal. The Hartford Steam Boiler Insurance Company was requiring all commercial Boilers to be pipe this way if they wanted the purchase insurance form them. This installer used this new piping arrangement and the customer felt good about the new boiler.

@ethicalpaul, Not every boiler failure is in the newspaper. Not in 1870, and not in 2022. Just because your system that i believe is perfectly maintained (and impressive may I add) works with very little problem, does not mean that every system is up to those standards. (Heavens Knows by some of the pictures and problems posted herein) But there are systems that have not failed, be it minor or catastrophically, as a result of a Hartford Loop. I know this because the Hartford Steam Boiler Insurance Company would have gone out of business long ago if their recommendations did not reduce the boiler failure rate from one or more daily, to the numbers we see today of less then one a month, and catastrophic failures that make the news are years apart.

So history tells us the the Loop (that may be useless for the problem you describe) does solve other problems that you can't imagine.

Also Paul, there were thousands of boilers without equalizers and Loops that operated flawlessly for years without failing. Just because it does not have a loop, does not mean it must fail. History does show that boilers with the loop fail at a lower rate then those without.

But they can still be useless for whatever scenario you believe it should solve.

I can see it in my minds eye, the pressure in the boiler pushing the steam up thru the pipe and also pushing the water level in the boiler lower, just a little bit. Can you picture it in your minds eye? Can you?

...all the vents clogged and no air getting out and the burner is firing but the thermostat is not satisfied, then the LWCO float is stuck on the mud in the bottom of it because it has not been flushed for several months, the burner cycles on the pressure-trol until the pressure-trol gets stuck in the closed position and the burner no longer cycles and the pressure builds, the water level drops lower and the homeowner gets home to find the boiler is raging hot and turns off the switch when they see the relief valve blowing off at 15 PSI.

I wonder if that boiler would still be there if the Hartford loop was not there?

ethicalpaul

I appreciate your story but the hartford loop has nothing to do with it, nor would have prevented it. Sorry!

SteamingatMohawk

I think to put it simply, the Hartford Loop does provide an intended purpose or desired outcome for a specific failure mode for a finite amount of time. Whether that failure mode is 10%, 1% or 0.01% of all failure modes is highly debatable. The fact is it is more than 0%, therefore it does have some use.

Obviously, with any "complex" system there can be many failure modes, each potentially justifying additional capabilities to prevent the most likely/serious failures depending on many factors.

Great discussion with differing perspectives.

EBEBRATT-Ed

@ethicalpaul

There is one HUGE point that is being MISSED.

What did every COAL fired CI boiler that didn't have a low water cutoff have?

Answer: A fuesable plug located over the fire box

The job of the fuesable plug located over the fire box was to melt and dump water onto the coal fire and put it out.

It couldn't put the fire out if the boiler ran dry

The Hartford Loop was to make sure the boiler never got dry. If the boiler lost it's feed water due to low water or a return line leak (unless the boiler itself was leaking) as the boiler steamed the water line lower the plug would melt dropping the remaining water on the fire to try and save the boiler.

The equalizer (with or without a Hartford) from the header drains the header, that is on today's small water content boilers.

In the old days (and the not so old days) steam boilers could be piped like a hot water boiler. I have seen plenty of them, steam supply out the top, gravity return in the back (with a check valve in the return) and they lasted 40, 50 100 years. Ran perfectly silent, no header , no equalizer

Why, first because the sections were thicker, oversized boiler, and a huge steam-water disengaging area.

The ran fine and didn't need a header, a drop header or an equalizer and ran quiet and produced dry steam.

Hartford steam boiler came up with the Hartford loop for two reasons,

1. The steam and return pressures are the same at the boiler and are lower at the far end of the system. Building steam pressure will put steam into the supply and push condensate back out the return towards the vent valves (High pressure goes to low pressure)

The check valve solved that problem for a while but when it got stuck it was useless.
The Hartford would allow a little water to back out, but once the water level dropped to the Hartford no more could get out & It would keep the water in the boiler for a while

2. to keep water in the boiler to drown the fire via the fuseable plug.


Boilers designed for automatic firing (oil & Gas) don't need a fuseable plug

ethicalpaul

That is very cool, thanks, I never heard of that fusible plug.

Next time I install a coal boiler I'll be sure to get myself one of those

So you agree @EBEBRATT-Ed that the hartford loop doesn't do anything today relating to safety?

EBEBRATT-Ed

@ethicalpaul

Might save the boiler for a short time that's about it. But it does keep water from backing out of the boiler. I think most boiler MFGs want the bottom of the Hartford 2-3" below the normal water line.

Think about the boiler water level going to the level of the HL tee. As soon as it gets down there steam pressure from the header will keep the water from backing out of the boiler......and back out it will.

EBEBRATT-Ed

@ethicalpaul

Think about a commercial boiler with boiler feed pumps. They usually don't have nor do they have any need for a Hartford. The water would back up to the boiler feed pumps. The only thing keeping this from happening are the check valves.

Inspectors that insist on a HL with boiler feed pumps do that because they see it in a picture so they think they need it

SteamingatMohawk

I'm only referring to single pipe systems.

@ethicalpaul can you acknowledge that there is some non-zero usefulness in having the HL in single pipe systems?

If there is zero, why would the Hartford Steam Boiler Insurance Company have created it? What would have been their motive?

Here is some history from the company's web site.

https://www.munichre.com/hsb/en/about-hsb/hsb-group/history.html

In part it says, “Though the insurance offered financial interests, it was secondary to safety and loss prevention – a totally new concept for an insurance offering.”

SteamingatMohawk

I wonder if there is any credible historical information as to the timing for when new "capabilities" were implemented. Specifically, the Hartford Loop (late 19teens), equalizer, low water cutout and auto feeder. Some of them might have been patented.

Dan_NJ

EBEBRATT-Ed said:

@ethicalpaul

There is one HUGE point that is being MISSED.

What did every COAL fired CI boiler that didn't have a low water cutoff have?

Answer: A fuesable plug located over the fire box

The job of the fuesable plug located over the fire box was to melt and dump water onto the coal fire and put it out.

It couldn't put the fire out if the boiler ran dry
...

Boilers designed for automatic firing (oil & Gas) don't need a fuseable plug

I wasn't aware there was anything like this in the old coal fired days but it makes sense. It seems like rather than a Hartford loop, or maybe in conjunction with it, in order to have similar protection in a "modern" boiler we would need an additional safety that would close the gas valve or shut off the oil pump, or at least interrupt a call for heat, at some designated temp inside the boiler.

EBEBRATT-Ed

@Dan_NJ

If you ever find an old coal fired CI boiler and open the fire door you will see a threaded plug in the bottom on the crown sheet of the boiler probably 3-4 sections from the front of the boiler.

The "fuseable plugs" were just a 1/2" brass pipe plug they would drill a hole in it and fill the hole with solder or something like solder that would melt if the boiler overheated. As long as there was water in the boiler it wouldn't melt

Dan_NJ

It seems like an over temperature shutoff of some kind makes sense to have. Cost benefit of it I have no idea, but it seems like a good idea.

ethicalpaul

SteamingatMohawk said:

I'm only referring to single pipe systems.

@ethicalpaul can you acknowledge that there is some non-zero usefulness in having the HL in single pipe systems?

If there is zero, why would the Hartford Steam Boiler Insurance Company have created it? What would have been their motive?

Here is some history from the company's web site.

https://www.munichre.com/hsb/en/about-hsb/hsb-group/history.html

In part it says, “Though the insurance offered financial interests, it was secondary to safety and loss prevention – a totally new concept for an insurance offering.”

I stated a couple nice aspects about the hartford loop earlier in the thread, but no, I don't think it adds any safety that's worth anything, definitely not today. As I have said too many times, you get like under an hour of additional time in the case of a catastrophic return leak. I acknowledge that a lot of leaks are slow, but if they are slow then the slowness of the leak is what is saving you, not the hartford loop. The LWCO is the savior.

On this site there have been several contractors who posted about present-day boiler failures where the boiler went dry and started to burn. Where was the Hartford loop then? Where are the stories about the Hartford loop actually doing some good that aren't made up ones from the 1900s like earlier in this thread? (with respect to Ed, he did admit it was a made up story)

What was their motive? Surely their motive was to reduce claims, but maybe their actions were misguided. Have you ever known a company to make a mistake in its judgment? Or maybe there is some benefit to the hartford loop, it's possible. But I haven't heard it yet. Have you???

The web site is interesting to me in a couple ways, thanks for posting it. First, they are talking repeatedly about "steam power". I believe that the boiler explosion every 4 days was not in residential heating, but much more likely was in boilers used for steam engines where they are working with much higher pressures and the margin for error and the possibility of horrific failure was much higher. Every plant had steam engines and there were lots of mobile ones too I think.

The second interesting part is this: "there was also widespread ignorance about the properties of steam and the causes of boiler explosions."

So at least some dead men didn't know what they were talking about, at least according to the Hartford Steam Boiler company.

SteamingatMohawk

@ethicalpaul Agreed about the content of the reference, that's why I didn't include more text...it would have taken us off topic.

I admit to challenging you a bit about the extent of the usefulness of the HL, but it does have some.

Like any invention, there is a lot of learning in the "design development" stage. I believe it took many tries before Thomas Edison developed a useful light bulb.

I did not find anything specific to single pipe residential systems, but the perspective of what went on in those days is educational and eye opening. Perhaps it should be required reading for those not deeply familiar with how steam boilers work. Then maybe they won't do unwise things (like one of my pet peeves of leaving a low pressure gauge in service when not needed).