What is the purpose of this vent type fitting, on this one pipe steam system radiator?

Dennis

The fitting is 3/4 inch.

Fred

That's not a vent fitting and it serves no purpose on a single pipe steam system. It looks more like a drain plug or maybe just a plug that someone put in it to convert it from a hot water radiator to a steam radiator. That radiator

Steamhead

That should be a Monitor "Bi-Loop" radiator. It was made to hold a quantity of water, and the incoming steam would heat the water, which would hold its heat longer than cast-iron would by itself. The drain was so you could winterize the radiator so it wouldn't freeze.

Somewhere, I have a diagram of these radiators.

JUGHNE

So was there a "dam" to retain that water to one side so as to not produce water hammer as steam entered?
I understand the added mass of the water.
If heated to steam temp and then going into a vacuum would that water boil? WAG.

Steamhead

Found it- this is the 2-pipe version, but it works the same way:



@Erin Holohan Haskell , this might be good to add to the Heating Museum under Radiators.

delta T

huh. learn something new every day! thanks @Steamhead

Erin Holohan Haskell

Steamhead said:

Found it- this is the 2-pipe version, but it works the same way:



@Erin Holohan Haskell , this might be good to add to the Heating Museum under Radiators.

Fantastic! Thanks, @Steamhead. Where'd you track it down?

Mike_Sheppard

Wow, that is really neat. And something I would have never thought. Thanks for sharing that @Steamhead

the_donut

Seems like a half way between steam and water. Notice the big cutdown on sq ft edr.

Fred

Yes, with the reduction in EDR, I'm not sure it was a very good idea. Kind of self defeating. Guess that's why it is now a rarity.

Steamhead

Erin Holohan Haskell said:

Fantastic! Thanks, @Steamhead. Where'd you track it down?

1922 ASHVE Guide. That company doesn't appear in later Guides, which makes me think they didn't last long. Perhaps the reduced heat output and/or increased cost had something to do with it. But I've seen these in Baltimore, and as usual, was the only one who had worked on the system to know what they were

Big Ed_4

Learn something every day, thanks... I wonder if its thought of use was for Appartment buildings ?

Mike_Sheppard

@Steamhead when I run into something like this is DC I'm contacting you lol

Erin Holohan Haskell

Thanks!

Erin Holohan Haskell

Here it is: https://heatinghelp.com/heating-museum/monitor-bi-loop-hot-water-radiators/

Thanks, @Steamhead! Your knowledge of these older systems continues to wow me.

Steamhead

Erin Holohan Haskell said:

Here it is: https://heatinghelp.com/heating-museum/monitor-bi-loop-hot-water-radiators/

Thanks, @Steamhead! Your knowledge of these older systems continues to wow me.

Well, that's why we're here. BTW, I just found an old Monitor Bi-Loop catalog online, and it's on its way to Baltimore. I'll go through it when it arrives and will likely post more stuff here- watch this space.

Erin Holohan Haskell

Fantastic!

Mike Cascio

Wow this is neat. I suspect it would work well.