Pipe Pitch and Pipe Insulation

Steve_211

I know that the steam return has to be pitched. How much per linear foot and can it be pitched too much or it doesn't matter? Regarding insulation, I insulated the main. Should the return be insulated too or that doesn't matter?

EdTheHeaterMan

Minimum is 1" per 20 feet. Yes, insulate the return.
And you can pitch a return pipe as much as 90° from horizontal. So no, you can not pitch a return too much. But if you have a horizontal wet return (below the water line), and it has only the minimum pitch, you will want to make provisions to flush that pipe from time to time. Lots of muck, sludge and other nasty gunk, (gunk is a technical term) will spend lots of time reducing the flow of return condensation back to the boiler.

EBEBRATT-Ed

Depends what the return temp is. Payback is probably not worth the insulation cost. I would concentrate on any pipe with steam in it.

Steve_211

You advise, EdTheHeaterMan, to insulate the return. Initially, I didn't see the efficacy in doing that since the return is not carrying steam to the radiators, but returning condensate back to the boiler.

EBEBRATT-Ed, you say it depends on what the return temp is. Since the return returns condensate water back to the boiler, wouldn't it not matter, in fact, be better if the return wasn't insulated as this would expedite any remaining steam to condense back to water to return back to the boiler?

Jamie Hall

Wait. Are we talking a dry return here, or a steam main extension? If it's a steam main extension, if should be insulated. If it's a dry return, it should never have steam in it -- and doesn't need insulation.

Steve_211

To Jamie Hall: All the pipe from the riser off the header had insulation on it. Years ago, I removed the pipe insulation from the last radiator takeoff back to the boiler (the return) on my one pipe system. Was this OK?
What would cause the return to have steam in it and how does one determine that there is steam in it?

Jamie Hall

Usually a one pipe system doesn't have a true return, but an extension of the steam main which is there to get condensate back to the boiler. It really should be insulated, but it's not a tragedy if it isn't. You will only get significant steam in it if there is a vent on it somewhere down the line -- and you can easily tell -- if it gets steam hot, or nearly so, it's accepting steam and insulation will save a bit. Not much...

EdTheHeaterMan

As far as insulation goes, it depends on the quality of the studio construction. I hate it when you are trying to make a recording and you get the noise of a firetruck siren going by, on you demo tape

Intplm.

Oh @EdTheHeaterMan , is that the circle of fifths on that pitch pipe? Maybe we can get the steam whistle pitched to a tune? LOL.

Steve_211

To Jamie Hall: The steam main extension (the not so true return) does have a vent on it, a Gorton Air Eliminator #1, at the end where it drops back to the boiler, near the hartford loop. When the system is cool, the valve in the vent is open, as I hear it make noise when I knock on it. When the system is operating, the valve in the vent is closed as it doesn't make noise when I knock on it and it's hot. Is the vent necessary? Can it be removed and the venting of the system be adequately handled by the vents on the radiators?

Tuggy

Steve_211 said:

Can it be removed and the venting of the system be adequately handled by the vents on the radiators?

Wouldn't that be considered a main vent and therefore should not be removed?

KC_Jones

Steve_211 said:

To Jamie Hall: The steam main extension (the not so true return) does have a vent on it, a Gorton Air Eliminator #1, at the end where it drops back to the boiler, near the hartford loop. When the system is cool, the valve in the vent is open, as I hear it make noise when I knock on it. When the system is operating, the valve in the vent is closed as it doesn't make noise when I knock on it and it's hot. Is the vent necessary? Can it be removed and the venting of the system be adequately handled by the vents on the radiators?

Definitely don't remove the main vent. Balance starts with main venting, without it balance becomes and issue, as well as speed of filling the mains.

Jamie Hall

That vent, as the folks above have said, is actually the main vent for that whole line of piping. You very much need it. In fact, if it's just a #1, I would not be surprised if the system could benefit from a #2 instead.

Steve_211

To KC_Jones: Point taken.

To Jamie Hall: Point also taken, and your suggestion to upgrade to a Gorton #2. I will definitely be doing that. Also, being that I removed the insulation from the extension of the steam main, would it be advisable to re-insulate it?

Jamie Hall

Yep.