Help understanding radiator - how it works, and leak options

neps

Hi - we recently purchased a 100 yr old home with steam heat. My previous home had hot water radiators - so this system is a bit more confusing.

We have a lot of radiators like the images below. One of them is leaking near the "arm thing" on the top right. I can't tell what I should be doing.. turning the screw in or out? rotating it clockwise or counter clockwise?

Any advice on how this system works or how I can adjust this?

thanks for your help and looking forward to being a part of this forum

Danny Scully

Where are you located?

neps

Just outside Philadelphia, PA

BobC

It looks like you have a vapor heating system that can be very comfortable and economical if it is kept in good condition. That valve probably has to be taken apart and looked at and it takes some expertise to do that. It may not be repairable and will have to be replaced with a different type of valve. This is a list of contractors in that area who have registered with this site.

https://heatinghelp.com/find-a-contractor/state/PA

If any are close to you call them and tell them you have a vapor steam system with a leaking valve that needs to be addressed, mention that you have an post on heating help where they can see a picture of the valve that is leaking.

Bob

neps

Thanks Bob! Appreciate the insight on vapor heating system, wasn't sure what to call it.

We have about a dozen or so of these type of radiators. Can you tell me more about the valve? The little handle on the top - some of them have like a bunch of divots on the top so it looks like you can rotate it around - does that make the system have less or more heat? also does the screw on the side do anything?

nicholas bonham-carter

The arm thing is a steam inlet valve. Is water leaking from the valve handle, or from the connection of the valve body to the radiator?
These systems can be truly wonderful, but only if properly maintained. They can heat with just a few ounces of vapor, with less pressure than it takes to blow up a ballon. It is possible that the pressure control on the boiler has allowed overpressure.
A good steam pro will check the whole system for proper operation.--NBC
PS, I must add that the system appears to be trapless, and that the valve was specially selected to enable only the amount of steam to enter the radiator which could be condensed, when the valve is fully open. Closing the valve slightly would lower the output of the radiator in milder parts of winter.

BobC

That valve will allow you to adjust the amount of steam entering the radiator and thus the amount of heat it produces. If the valves have not been adjusted in a long time they mey be a but stiff so use care. i don't know what the screy on the side does but I'm sure someone more knowledgeable will chime in.

I agree with Nicholas's advice to have a competent steam pro check the system out.

Bob

Jamie Hall

I'd need to look at it to be certain, but I think the screw on the side adjusts an orifice. It should be set so that with the main valve -- the top handle -- fully open, and the boiler having run for a while (say 20 to 30 minutes) the radiator is hot almost all the way across. Once it is set, it never needs to be set again. The top handle then adjusts the amount of heat from the radiator.

As regards the leak, where is it leaking from? That can affect how easy it is to repair -- if it is repairable.

And second, the maximum operating pressure of the system should be not more than 10 to 12 ounces per square inch. That is limited by the vaporstat on your boiler. Could you possibly post a picture or two or three of the boiler, showing all the controls and piping, and a closeup of the pressure controller?

neilc

we all looking at the round head machine screw there ?
isn't that just missing a ceramic / plastic / ACM type handle ?
and maybe acting as a set screw to the casting and the valve stem ?
the drop on the casting probably stops on the bonnet, and there would be some "limiting" by where you set the casting on the squared top stem,
( I think I have a few a work )

Jamie Hall

I was assuming that the OP was referring to another screw on the side of the valve body. If it's just that big machine screw we see -- yeah, just a missing handle.

neps

Thanks all!

Looking at the other radiators - i think you are right and it's just missing a piece of a handle (the perpendicular screw)

I've marked on one of the attached photos where the water/steam was escaping from. I wasn't sure if rotating it like a screw (clockwise) would make it tighter, even close off the whole radiator if we wanted?

Included a some photos of other handles as well.

neilc

yeah, so your red arrow is pointing at the packing nut, I see the slight flats there on the upper raised edge,
gently with a wrench try loosening and tightening there,
you may eventually tighten down a bit and stop that leak,
or will you'll have to repack it,
see if you can get it moving first,
don't damage the center stem,

nicholas bonham-carter

Also try to get the pressure as low as possible, as it may have risen, pushing the packing nut beyond its weakened condition.
With a very low pressure, it may hold water without a lot of tightening.--NBC

Gordo

@neps: Hi! It looks like what you have is a "Broomell System" of vapor heating.

"Vapor" is a term of art for really low pressure steam heating.

Broomell systems are turn of the last century systems that were designed to operate at pressures of a few oz/in2 or well below 1/2 psi.

As others have advised, your first order of business is making sure that the pressure in your boiler that is heating those radiators is controlled by a "vaporstat" (a pressure regulating device on the boiler designed to keep the pressures in the "vapor" range) and for added benefit a gauge on your system that can read these low pressures.

Next order of business is to verify that air can easily exit your system somewhere.

Once you get the pressures down, any leaks on those valves may drop to insignificance. However, I am sorry to say that Broomell valves are difficult to repair and may need replacement on a planned basis eventually. They are almost 100 years old.

My company has serviced Broomell Systems and some of our customers are located in the Philly area. Please give us a call.

neilc

@neps @Gordo

Gordo said:

@neilc: Hi! It looks like what you have is a "Broomell System" of vapor heating.

"Vapor" is a term of art for really low pressure steam heating.

Broomell systems are turn of the last century systems that were designed to operate at pressures of a few oz/in2 or well below 1/2 psi.

As others have advised, your first order of business is making sure that the pressure in your boiler that is heating those radiators is controlled by a "vaporstat" (a pressure regulating device on the boiler designed to keep the pressures in the "vapor" range) and for added benefit a gauge on your system that can read these low pressures.

Next order of business is to verify that air can easily exit your system somewhere.

Once you get the pressures down, any leaks on those valves may drop to insignificance. However, I am sorry to say that Broomell valves are difficult to repair and may need replacement on a planned basis eventually. They are almost 100 years old.

My company has serviced Broomell Systems and some of our customers are located in the Philly area. Please give us a call.

neps

here are some pics of the boiler

Gordo

Looks like you already have a Vaporstat. That's good! The 30 psi gauge must remain there per Code, but a 30 oz/in2 is a good addition to show what pressures you are really operating at.

I see that the vaporstat in your photo is set at 14 oz/in2. For the Broomell system, that's usually about 10 oz/in2 too high. The vaporstat may be off adjustment (they often are inaccurate right out of the box!) The pigtail may be clogged, too.

How is air leaving your system?

Here is a video I just made for you on the Broomell valves I have in my collection. They may be somewhat applicable to your valves. Please let me know.

https://www.youtube.com/watch?v=r6Kii5K_wps