Dry steam visible? How to check?

Daniel_3

Unless the environment that the steam was escaping through (main vent tapping) was the same temperature as the steam you would always see the steam as said environment has much moisture in the air. Dry steam is a not really easy to measure. It's really a matter of "drier" steam than that which has much water carryover from the primary risers from the boiler. Many factors come into play such as ph and cleanliness of the water being boiled, the near boiler piping layout, and size and diameter of the piping. These are of primary importance when trying to achieve the most unsaturated "spread out" steam from the boiler and feeding all the radiators of the system with this latently energized steam. True that if the pipes were see-through and you had all the factors at a premium then you would probably not notice much visible steam in the pipes. I'm not sure actually how it would look if all the factors were right. This of course is according to what I have studied to a small degree and experienced myself in a very greenhornish way.

Chas_2

Dry steam visible? How to check?

Dear All
First of all I love this site! I love steam heat, and I'm glad I finally found a resource to optimize it.
So, I have a one pipe, dry return, oil fired steam heating system. To try to diagnose my uneven heat, I have been poking around here. I also bought the steam heat books fron this site. I now know wet steam is the enemy of efficient steam heating. So I took off the vent on the main that was slow to heat. Steam eventually came out, but it was VERY visible. So this is wet steam. Now if my system was producing dry steam, I would not have seen it? I would have been burned and not seen it coming out the 3/4" hole were the main vent was removed? I know the near boiler piping is wrong and I am planning on redoing it properly. Just for kicks I wanted to see if the slow main would heat quicker if the vent was removed. I suspected a blocked vent and found the wet steam.
I read somewhere here that wet steam will show up on the inside of the boiler level sight glass as sweating. I do not see that so I assumed it was dry steam.
Anyone have thoughts about this?
Thanks,
Scott

Brad White

Visible Steam

Steam itself is not visible. Any time you "see steam" it is really condensed vapor. Try to argue that point with some people and you get them very upset but it does not change the facts.

Low pressure steam when introduced to atmosphere almost immediately drops below it's saturation point, hence becomes visible. Yes it is wet steam, but it was not wet necessarily, until you let it out of the system. Even with dry steam, you would have seen it when it escaped. The dryer and/or the more superheated was the steam to begin with, dictates how much "clear tail" you have before it becomes a cloud.

High pressure superheated steam on the other hand, is invisible for some distance and will cut you to the bone. (Navy steamfitters know to take a broom waved ahead of them as they approach the deafening roar of a SHS leak. When the broom gets cut off, that is where the leak is.)

The parents of little whisk brooms are aghast when they find that their children want to join the navy when they grow up.

I have seen superheated steam leaks and they are awe inspiring. Nothing visible for about ten feet then a sudden isolated cloud appearing out of nowhere like a swarm of bees.... even made snow once but that is another story...

WET steam on the other hand is steam with entrained moisture (over 2 percent by definition) but is also hovering on, nay straddling, it's saturation curve. The steam itself when isolated may be dry but if velocity is high, there may be entrained sensible moisture.

Unknown

Dry steam and wet steam

A picture is worth what Brad said...

Notice that it IS clear inside the piping.

Noel

Chas_2

you guys are crazy!!!
I would have loved to seen that in action! Those pipes look very similar to the ones we use in chemistry labs, where the drains are plumbed with glass and have rubber joint connections.
Love those pics.
Thanks

Unknown

Here's some more, Scottie

http://steamheating.googlepages.com/home

Noel

Unknown

That's cool,,,

I used to work at a place that had a pyrex refrigeration system for a trainer, that was cool too.

yes, you never search for a superheated steam leak with your hands, you will lose your fingers etc, upside is it simultaneously cauterizes the area, so you won't lose any blood. Never had to search for one myself but we were told either the broom trick or an inspection mirror which would fog up on contact with the steam.

I DO recall #1 Boiler room on my ship blew a mud drain off one of the boilers. My buddy Henry was down there at the time. I saw him just afterward, Henry was white as a ghost and shaking. I took that it was pretty scary, to say the least. Our steam was 1200 PSI and registered ~1080 PSI and ~1000*F. It entered the main engine turbine at that pressure and left the other end in 28" of vacuum. Now THAT'S squeezing the energy out of a medium. The condensers were held in a vacuum by steam powered air ejectors. We used to light our smokes off the the main steam valves, that's how hot they were. Down by the equator the machinery spaces tended to run at ~140* ambient. Supply air from the outside would come in through vents at 100* and you'd stand under one and say AHHHHH, because it felt so cool.

Steamhead (in transit)

Was talking to

a Navy Master Chief about how We heat buildings with only 8 oz/in2 steam pressure, max.

He cast me a baleful stare and then growled with contempt, "That's not Steam, that's a LEAK!"

Heating buildings with a leak.

Go Steam!

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Mike T., Swampeast MO

I had my first encounter with REAL steam after servicing my mod-con this year. A pin-point leak in the gasket between the burner and the combustion chamber was producing a HUGE amount of condensate on the outside of the chamber with the burner at full fire.

"Hot freaking knife" is the only way I can describe what I could not see but only felt...