Worlds smallest header?

Charlie from wmass

1 1/4" is big enough for this right? Smh

ChrisJ

You see a header there do ya?

SWEI

I find calculating the steam velocity can be entertaining at times http://www.tlv.com/global/TI/calculator/steam-velocity-through-piping.html

After derating for altitude, the 211A I posted a few weeks back would hit 145 FPS through 2" Sch.40 at 0.5 PSI.

ChrisJ

SWEI said:

I find calculating the steam velocity can be entertaining at times http://www.tlv.com/global/TI/calculator/steam-velocity-through-piping.html

After derating for altitude, the 211A I posted a few weeks back would hit 145 FPS through 2" Sch.40 at 0.5 PSI.

What I don't understand about steam velocity ratings is they never seem to agree with how long it takes steam to hit my main vents?

The fastest time on my long 2" 29' main is about 60 seconds. Shouldn't it be more like 2 seconds?

Charlie from wmass

The steam is collapsing as it approaches your vents Chris. If the pipe was already at 212 degrees at the scene entered it it would vent faster. The same velocity charts are based off of a system that is already up to temperature at the speed that travels to the Steam that is being used

ChrisJ

Charlie from wmass said:

The steam is collapsing as it approaches your vents Chris. If the pipe was already at 212 degrees at the scene entered it it would vent faster. The same velocity charts are based off of a system that is already up to temperature at the speed that travels to the Steam that is being used

How much could the main have cooled off in 5 minutes with 1" insulation?

Charlie from wmass

It would have to be below 140 degrees or your vents will not open to allow air in.

ChrisJ

Charlie from wmass said:

It would have to be below 140 degrees or your vents will not open to allow air in.

Not true.
My vents are located in a cold crawlspace and they are not insulated, nor is the 3/4" nipple connected to them. This nipple drops below 180F in about 4 minutes.

The insulated steam pipe is without a doubt still above 180F in 5 minutes.

Charlie from wmass

I suggest you insulate the nipple. Or even better relocate the vent to a warmer area so it takes longer to cool.

ChrisJ

Charlie from wmass said:

I suggest you insulate the nipple. Or even better relocate the vent to a warmer area so it takes longer to cool.

What benefit would this give other than making the system struggle trying to push air out?

All of the radiator vents will still be wide open.

In fact, I'm betting this would cause all sorts of balancing problems. Half the main full of air, half not, main vents still shut etc.

I rely on that nipple to cool to reset the Ecosteam, especially when it's below zero out and I'm running 3 CPH. I have around 5 to 6 minutes in between cycles.

Charlie from wmass

If the vent is warm and close what air would be stuck?

ChrisJ

Charlie from wmass said:

If the vent is warm and close what air would be stuck?

The 10 wide open radiator vents will let air in.

Steamhead

ChrisJ said:

You see a header there do ya?

That installer was a "good hot-water man" . And yes, you have me beat- smallest one I've seen was 1-1/2".

Jamie Hall

That problem of the apparent velocity of steam in a main being much less that the calculated velocity is kind of subtle. However, until the boundary layer of steam against the pipe reaches 212 (at "normal" atmospheric -- but close enough) steam simply will not go significantly farther -- it will, quite happily condense. If the pipe is nice and warm -- your 180, @ChrisJ , for instance, that will happen fairly quickly -- but not instantly. So the bottom line is that the steam front in the pipe will move only as fast as the steam will heat the pipe.

Oddly, the back pressure from a vent won't affect this all that much -- assuming the vents are at least reasonable. Which debate I have no intention of reopening...

Saturated steam is funny stuff.

jumper

Has anyone probed a steam system and measured 212°?

ChrisJ

jumper said:

Has anyone probed a steam system and measured 212°?

Not sure I understand your question?

jumper

ChrisJ said:

jumper said:

Has anyone probed a steam system and measured 212°?

Not sure I understand your question?

I figure that at 0 psig it's cooler than 212° unless there's no air in system. Because the partial pressure of the water vapor is less than 0 psig.

Charlie from wmass

New boiler new Header

Fred

Looking good!

Charlie from wmass

Thanks. Definitely better than what they had.

Paul S_3

Great job!! @Charlie from wmass

New England SteamWorks

Charlie saves another one. Nice job!

njtommy

That's some really thick insulation for those small pipes. lol.

Looking good Charlie.

ChrisJ

jumper said:

ChrisJ said:

jumper said:

Has anyone probed a steam system and measured 212°?

Not sure I understand your question?

I figure that at 0 psig it's cooler than 212° unless there's no air in system. Because the partial pressure of the water vapor is less than 0 psig.

0 PSIG is typically 14.7 PSIA, which means a boiling point of 212F at sealevel. Above sealevel, this temperature should gradually drop as you get higher and higher.

At 2000 feet it's 13.7 PSIA so a boiling point around 210F.
At 5000 feet it's 12.2 PSIA so a boiling point of about 202F.

jumper

Boil water in an open pot. Stick a thermometer into the steam –not the water– and see if you get 212°.

ratio

If you can see it, it's by definition not steam. It's already condensed. Use a teapot, & put the thermometer in the "empty" area between the spout & the cloud. That outta be a lot closer to 212, depending on altitude/barometric pressure.

jumper

Spout increases velocity to sweep away air. My point is that when there's air in a steam heating system the gases are less than 212° at 0 psig because part of the pressure is contributed by the air. So the water vapor pressure is less than 0 psig. Or am I missing something?

Charlie from wmass

Steam displaces air. They do not blend due to difference in densities.