Hartford Loop design origin

pacoit

Did the Hartford Insurance Co. 'invent' the Hartford Loop? Or was it already used in a few installations and the Hartford promoted it by requiring it?

109A_5

https://heatinghelp.com/news-and-media/dead-men-tales/the-hartford-loop/

Sounds like the Hartford Steam Boiler Insurance and Inspection Company invented it.

EdTheHeaterMan

The Hartford Steam Boiler Inspection and Insurance Company (HSB) is a global specialty insurer and reinsurer headquartered in Hartford, Connecticut. Back in 1919 they invented the Hartford loop. By 1919 HSB got tired of paying for all those steam boiler failure claims and mandated all boilers that were insured by HSB to have the piping design they invented or they would not cover the boiler. HSB was founded in 1866 by members of a group known as the Polytechnic Club.

pacoit

Thanks for the info. I didn't know Hartford described it as early as 1909.

The reason I posed the question is that the Hartford Loop as a hydraulics concept for limiting flow in a vessel struck me as something that may well have been around longer, at least among hydraulic scientists and engineers. Perhaps not. Just curious.

EdTheHeaterMan

Sorry that 1909 was a typo. I corrected it to 1919.

ethicalpaul

It doesn't limit flow in a vessel

mattmia2

it is just a trap with a vent to keep it from forming a syphon.

pacoit

Well, I guess from a steam boiler point of view it keeps the boiler from draining in case the the return piping breaks low in the system. But, I meant it as a general concept.

EdTheHeaterMan

https://forum.heatinghelp.com/discussion/comment/1857665#Comment_1857665

Do you have proof?

ethicalpaul

you can’t prove a negative. Do you have proof it does?

I mean it does prevent draining if your wet return dissolves, like a watering can holds water, but I don’t think that’s what we’re talking about. If that’s all we’re saying then I’ll shut up

Alan (California Radiant) Forbes

Does a plumbing p-trap limit flow? If the Hartford Loop limits flow, it's inconsequential and unintended.

EdTheHeaterMan

Paul, I never said that it does limit flow, so why would I need proof that it does, I was just asking if you have proof for your statement (the one that I quoted you on). The OP was the one that stated that the flow was limited. And I believe that there is a misunderstanding. The OP may have been referring to the fact that a broken return might allow All the water to leave the boiler without a Hartford Loop, while the Hartford loop Limits the emptying of the boiler thru that broken return to the point at which the close nipple is located. The flow is limited to an inch or two above the crown sheet of the boiler if the close nipple is properly positioned.

So in the context of the OP's statement of limiting the draining of the boiler completely, to that of draining the boiler to the Hartford Loop's location level, I believe that there is some limiting going on there. Just not in the sense of normal operation, but in the sense of the failure of boilers before 1919 and the amount of boiler failures that happening after the 1919 introduction of the Hartford Loop.

The numbers don't lie. But they didn't have video cameras and glass piped boilers in 1919 to see what is actually happening inside those pipes. The first practical motion picture camera was invented in 1890, and Tom was not really interested in where the water in a steam boiler was going when he invented it. He was more interested in taking pictures of people. The camera you used to video your glass boiler piping was manufactured many years later.

Jamie Hall

The Hartford Loop (or related Gifford Loop) was and is intended to limit loss of boiler water due to a leak in a wet return — and it does that very well indeed, as @EdTheHeaterMan said.

Now. Will it prevent a boiler low water condition entirely? No. Nor is it intended to. What it does do is give time, in the event of a large leak in a wet return — not unheard of in those days — to pull the fire in the boiler (or nowadays to turn the burner off!) before the water level in the boiler drops below the crown sheet or top of the firebox. Before the use of the Loop it was entirely possible for the boiler water level to drop below the crown sheet in a matter of a few minutes — or less — particularly in larger boilers operating under higher pressure; with a properly piped loop (including that equalizer thingy — note that without the equalizer the loop offers no protection) that simply can't happen, and the fireman has a fighting chance at saving the boiler. Or, nowadays, the low water cutoff.

It's also worth noting that even with the loop, if the boiler is allowed to keep steaming it will eventually run dry — it will take some time in old boilers with lots of water volume, but much more quickly in modern low volume boilers. If your fireman is paying attention, though, nothing bad will happen.

ethicalpaul

The insurance company mandated its loop in every house because that would give the fireman stationed in every house time to pull the fire, got it!

EdTheHeaterMan

https://forum.heatinghelp.com/discussion/comment/1857704#Comment_1857704

Said Paul with a sarcastic grin

Exactly correct Paul. You see back when boilers were hand fired, every building with a boiler has a fireman. in the residential home the fireman was often the wife who's job it was to keep the home fires burning along with the cooking and laundry. but by todays standards would be considered politically incorrect. But by todays standards there is no need for a fireman because the thermostat and the fuel is taking the place of the fireman.

Also, not every homeowner purchased boiler inspection and insurance policies. That was usually confined to larger buildings with larger boilers. in your home, there would not have been a large enough boiler to make the boiler inspection and insurance premium one of the things your grandparents would purchase. So no mandates Hartford Loop would be required.

Just to let you know, my maternal grandfather was a boiler fireman for the Philadelphia School District. He shoveled coal into those boilers for a living. So yes there were at least 4 fireman in that particular building. Thermostats and gas and oil burners made his job obsolete. Now that building has only one stationary engineer on site. He is also the guy that they call the janitor who sweeps that sawdust they put on the floor where a second grader pukes. But he has the Black Seal required to operate that boiler.

ethicalpaul

I love you all dearly but I must say it’s a challenge sometimes—different people move between residential and commercial in a thread and then you come in claiming the commercial term just used means a housewife 😅

PS: My paternal grandfather was that same man at a small schoolhouse in Marcelin, Saskatchewan in about 1915 and managed to more or less support 16 children! Look how much we have in common!