Steam heat: What does the Hartford Loop do?

[@LTVoyager]

Nice demo. As you said, it is the LWCO that will be the hero, not the Hartford Loop.

[@oldhandyluke]

Maybe you should dryfire this thing outdoors if you get it out in one piece, just make absolutely sure its not going to rain anytime soon LOL.

[@danieljanowiec1324]

One thing I would like to point out in this video is that when you see 1-2 inches of water left in the sight glass that doesn’t mean that’s all the water left in the boiler you probably have closer to 10 inches of water. Measure from the bottom of the t where you’re boiler drain is on boiler side of the return to the bottom of the tee on the Hartford loop. There’s still a good amount of water left. Hope this helps out.

[@pb7379-j2k]

True enough but it’s just a few gallons. It will boil out in some minutes

[@Nuchello]

MY GOD UNLESS YOU MECHANICAL CONTRACTOR WITH A MASTER PIPEFITTERS LISCENE NO ONE SHOULD BE EXPLAINING HOW A STEAM BOILER WORKS OUR LOL HAVE NO CLUE WHAT A HARTFORD LOOP DOES. AHHHHH EVERYTHING I SEEN YOU SAY IS INCORRECT. !! ILL LEAVE U WITH THIS 1 FACT THE HARTFORD LOOP IS FOR ALL RETURNS TO TIE INTO SO THE RETURN WATER FROM THE STEAM GOING TO RADIATORS DOES GO DIRECTLY BACK TO BOILER THAT CAUSES SERGE BRO ! THATS WHY YOUR SIGHT GLASS IS LOW AND MOVING WOOW 36 YEARS as a Master plumber and a Master pipefitter 1 and 2 and a Mechanical s6 in Conn. Also. I've never ever could imagine someone talking about a steam boiler and mentioning expositions get this off you tube please !!!

[@mugen-mundo]

The Hartford loop might be a remnant of the olden boilers. Were, it could take a long time to bring to a boil. Giving time for homeowner to putout the coal fire. The early boilers lack electronic controls like lwco or auto feeders. @@pb7379-j2k

[@johnmanning6572]

The efficacy of the Hartford Loop predates the invention and use of low water cutoffs, as you know. In the days when a coal fire continuously burned at damper regulated intensity in a steam boiler, the extra time the Hartford loop provided, in the event of a return leak would certainly have been valuable. Because unlike with modern, on again off again boilers, someone would have certainly checked on it every few hours to tend to the coal fire. Today? Well, considering the annual maintenance and safety checks that the average residential steam boiler receives, the Hartford Loop certainly doesn't hurt anything, and it provides a last, if only temporary, line of defense. From an insurance perspective, nothing is gained by eliminating it, and it just might help prevent a boiler launch (which by the way, I would love to have witnessed, back in the day).

[@pb7379-j2k]

That’s a lot of words to say “I agree with you 😂”

[@johnmanning6572]

@@pb7379-j2kLOL, I was on a roll. Really enjoy your videos, Paul.

[@mugen-mundo]

The loop also balances the pressure on both ends of the system. No Hartford loop and water level could rise on the condensate side creating a dry fire scenario, even though the boiler is at the correct water capacity.

[@pb7379-j2k]

No, that would be the equalizer

[@mugen-mundo]

@@pb7379-j2k Ahh yes good call. Like your videos and glass pipes by the way. Steam on sir.

[@pb7379-j2k]

@@mugen-mundo thanks!

[@Nuchello]

What pressure are you talking about ! STEAM Risers and turns to solid water and drains back to boiler YOU KNOW gravity lol wooow !!!

[@mugen-mundo]

@@Nuchello When steam is created it expands 1700 times. Thus creating pressure inside the boiler. That's what pushes the steam to the radiators. That's why steam boilers have pressure gauges too. The Equalizer ensures the same pressure exist on both ends of the system.

[@williammaloney2003]

Interesting experiment. I may be mistaken but I thought the Hartford Loop (before the invention of the low water cut off) prevented the boiler from draining lower than the top of the loop in the situation of a leak in the wet return. So eventually when there is no more condensate returning, and it has all drained out of the system through the hole in the wet return, there will only be water in the boiler to the level of the top of the loop, and water in the actual Hartford Loop pipe up to the level of the top of the loop. There would be no water on the side of the loop that connects with the wet return. So this is what prevents the boiler from dry firing. Or do I have this wrong?

[@pb7379-j2k]

You have it right, but then what happens? The boiler keeps firing sending steam into the system which returns as condensate to the leaking wet return which means your boiler dry fires in a few minutes anyway

[@williammaloney2003]

@@pb7379-j2k Makes sense. I was thinking that was more of an issue in the age of coal-fired boilers though, since they would run all day. With gas or oil fired boilers on thermostats, I figured they would eventually reach the set point of the thermostat and turn off before all of the remaining water in the boiler was boiled off. But I suppose over time with repeated cycles the water would still eventually boil off. I guess the benefit of the loop is that the water doesn't run out all at once and buys you some time, but still the end result could be a disaster.

[@pb7379-j2k]

@@williammaloney2003 also in the coal days they didn’t have LWCO and they went down to fill the boiler with coal several times per day so they’d check the water level too. Today many don’t look at the boiler for weeks at a time so the LWCO is the hero. The Hartford Loop is useless except it keeps some mud out of the boiler

[@jkbrown5496]

@@pb7379-j2k The Harford loop wasn’t a safety device as we now view such. It is/was an alert device for an attended boiler. The operator had more time to notice water loss and rake out the fire. Apparently, it worked in its time compared to before it was implemented. Take no hope in deleting the requirement. No insurance company or local code authority is going to take that risk, even if the loop has very low utility today.

[@raindogs451]

Paul, I had a question... I heard Dan Holahan talk of the value of a King Valve for a 10 psi boiler blowdown, and it got me thinking. In a dry fire arrangement is it a truth that pressure will build? It seems that the cubic feet of space associated with the boiler and perhaps a hundred feet of mains, returns, branches, radiators AND because it's not a quintessential pressurized system, I thought, "I wonder what it would it automatically raise pressure before some calamatous event?" While I'm familiar with pressure/ temperature relationships (I'm an AC guy), the potential venting made me wonder.

[@pb7379-j2k]

I don’t think I’m following-what is a “dry fire arrangement?” I would think if you ran the boiler dry the pressure would drop due to no more steam production

[@raindogs451]

@@pb7379-j2k That was exactly my assumption and question. It seems, then, that a supplemental pressuretrol as a safeguard for a dry fire occurance would actually be ineffective.

[@raindogs451]

@@pb7379-j2k On a related question I see firomatic and other heat sensitive type thermal safety switches above the boiler often installed, and looking at some of them they're preset and non adustable at 165. I might be wrong, but 165 two to three feet abobe the boiler jacket seems darn high---like" the damage is done" high. Am I wrong?

[@pb7379-j2k]

@@raindogs451 yes I think it would not help. To be safer from low water condition you can install another LWCO lower than the first. Multi family residence boilers require this in many municipalities

[@pb7379-j2k]

@@raindogs451 yes probably but they might prevent a fire. I’m not familiar with these. I’ve only seen high temp switches on the flue pipe swinging door thing

[@raindogs451]

do you have an automatic feed? Have you tested it with an automatic feed? I'd be interested in whether an automatic feed would keep up with a simulated leak. If I was swapping out a boiler Id think a heat switch above the boiler, another high limit strategically placed, a supplemental low water cut out-----all with a SPDT switch with an alarm of some sorts upstairs would be reasonable investments.

[@pb7379-j2k]

I had an automatic feed on this boiler. An automatic feed would keep up, if and only if the LWCO were working. The LWCO would cut off the boiler, then trigger the feed. All this happens regardless of Hartford Loop.

[@raindogs451]

So, your response? And is "they don't do anything" a bit overstated?

[@pb7379-j2k]

I don't follow your meaning

[@raindogs451]

@@pb7379-j2k I mean, as you know the name only came into existence by The Harford's response to hundreds of boiler explosions and it's been in use for decades and was the primary source of protection prior to electric LWP. I think your video was interesting in as much as I thought, 'If I was replacing a steam boiler I'd have a secondary LWCO, high limit and heat sensitive switch above the boiler." I think the video was good in highlighting the need for additional protections, and a warning the HL may impute a false sense of security. Without further testing, however, I didn't come away thinking "worthlesss."

[@pb7379-j2k]

@@raindogs451 If you think there is some protection they supply, please name it. If The Hartford really wanted to make boilers safer, they would have outlawed buried returns that rust out.

[@raindogs451]

@@pb7379-j2k Well, without thinking much about it, your video highlights a potential 5 minutes (I don't remember). so without a supplemental LWCO, and other supplemental safeties your video suggests the HL might be innefective. However, in the absence of the HL loop, and those supplemental safeties, I'd be hard pressed believing a make up feed would keep up. W ith the proper protections in place, I'd imagine the difference of 30 seconds and 5 minutes might be a significant interval. In other words, if you're sitting in the living room, would an alarm giving you several minutes to respond vs seconds make a difference?

[@pb7379-j2k]

@@raindogs451 What alarm? Residential boilers have a single LWCO. That is what triggers the automatic feed (if equipped). So without a working LWCO, you are sitting in your living room while the boiler steams away its water, and the Hartford loop gives you some minutes of extra time, which you will use watching the football game. Or it's at night, or you are not home. The Hartford Loop offers no protection, only some minutes of delay from dry-firing.

[@AZ-jz4ki]

Hartford loop is not designed to prevent dry fire of the boiler. It’s to equalize boiler pressure. Your whole premise is false

[@pb7379-j2k]

The equalizer equalizes pressure. An 18” vertical pipe (the Hartford loop) does nothing regarding pressure. My premise holds. Also preventing dry firing is the entire purpose of the Hartford loop. That’s why it’s named after the insurance company that mandated it.

[@rafieljimenez665]

You ain’t lying the company even stated if their system doesn’t have a Hartford Loop it would not function correctly