STEAM ENGINE QUESTIONS.

[Jstpssng]

The steam flow isn't reversed. Watch at about 23 seconds, they operate the reversing linkage. That changes the direction. The flow of steam stays the same.

You really had to be paying attention to see that one, and/or know what you were looking for. I backed it up about 1/2 dozen times before I saw what you are referring to.

 

[/pine]

My employer sent me to steam school (one day seminar) at a steam controls company. Man, that was an eye opener.... especially the video of a guy in a manhole when a steam pipe burst. 1600:1 expansion ratio when it's let loose! Guy got popped out of the manhole like a cork. He survived and walked away!

Here's the video. You can hear the steam hammer going on and the guys talking about how you couldn't pay them enough to be in that vault. Some guy says to the guy in the hole "Maybe you should set out for a minute." Guy comes half way out and BOOM! WARNING: Strong Language (no $%@#!!!).

Awesome...!
There are some experience tales (before video tech) that are equally as impelling but with much less good outcomes...

 

[MossRoad]

What blew up? I saw flames.

I put the lance from my Steam Jenny down and it twisted, catching me in the shoulder, wearing only a T-shirt. I have not used it since and REALLY don't like STEAM anymore!

If you listen to the video, you can hear a loud BANG every 5-6 seconds. That's steam hammer. Condensate has built up in the pipe to the point there's a water slug getting slammed down the pipe in a wave. The water runs back, forming a wave that blocks the steam and its again hurled down the pipe, drains back, plugs, is hurled, drains, plugs, hurls, drains, plugs, hurls.... eventually, in extreme cases, it can burst the pipe. If the steam pipe bursts, the steam reverts to normal water - violently expanding 1600 times its volume pretty much instantly. BOOM!

 

[MossRoad]

You really had to be paying attention to see that one, and/or know what you were looking for. I backed it up about 1/2 dozen times before I saw what you are referring to.

Yeah, that video shows it stopping and changing the reversing gear several times in the video. I'm kind of facinated by steam in the last few months. Both in trains and heating systems for buildings. Lots to learn.

 

[GLyford]

I have coworkers who were stationed on submarines. They talked about the official way to find a high pressure steam leak (which is usually just a very fine jet, but the passageway fills up with steam so you know you have one, somewhere):

You grab a broomstick and walk slooowly down the passageway next to the high pressure line, waving the stick in front of you. When the end of the stick starts getting chopped off in pieces as you wave it back and forth, you've found the leak.

 

[Egon]

Boiler make up water steam injector.

[video]https://en.m.wikipedia.org/wiki/Injector[/video]

 

[MossRoad]

I have coworkers who were stationed on submarines. They talked about the official way to find a high pressure steam leak (which is usually just a very fine jet, but the passageway fills up with steam so you know you have one, somewhere):

You grab a broomstick and walk slooowly down the passageway next to the high pressure line, waving the stick in front of you. When the end of the stick starts getting chopped off in pieces as you wave it back and forth, you've found the leak.

YIKES!!!

 

[Industrial Toys]

I thought you were literally speaking of a steam hammer, and couldn't quite understand that.

Now, I get it.

But what of the flame and flash?

 

[MossRoad]

I didn't see any flame. I'll have to look again.

 

[/pine]

I have coworkers who were stationed on submarines. They talked about the official way to find a high pressure steam leak (which is usually just a very fine jet, but the passageway fills up with steam so you know you have one, somewhere):

You grab a broomstick and walk slooowly down the passageway next to the high pressure line, waving the stick in front of you. When the end of the stick starts getting chopped off in pieces as you wave it back and forth, you've found the leak.

I've read stories of men losing limbs and even getting cut in half...have seen depictions in movies of broomsticks being deployed in search of leaks...

There is a common misconception between actual steam (gas) and moisture vapor...

 

[Industrial Toys]

I don't know how my Mom knew, but she told me several times, that you can't see live steam.

 

[Jstpssng]

If you listen to the video, you can hear a loud BANG every 5-6 seconds. That's steam hammer. Condensate has built up in the pipe to the point there's a water slug getting slammed down the pipe in a wave. The water runs back, forming a wave that blocks the steam and its again hurled down the pipe, drains back, plugs, is hurled, drains, plugs, hurls, drains, plugs, hurls.... eventually, in extreme cases, it can burst the pipe. If the steam pipe bursts, the steam reverts to normal water - violently expanding 1600 times its volume pretty much instantly. BOOM!

That also must be what causes the hammer in pipes of buildings which are heated with steam.

 

[Kernopelli]

1600:1 expansion ratio when it's let loose!

Great thread! I am a retired Stationary Fireman and have always found the properties of steam and it's generation to be fascinating. It's use as an energy source is ancient and goes back at least as far as Archimedes and is still the most viable energy source for many process and elec. generation applications today.

WATER expands by a factor of about 1600:1 when flashed to steam at atmospheric pressure.....hugely dangerous if uncontrolled! Rapid expansion from liquid to gas form is generally the bigger danger when compared to steam (a gas) being suddenly released to atmosphere where it quickly condenses back to a liquid. Not to play down the danger of sudden steam release or even "simple" leaks. I have seen minor steam leaks cut metal flanges or erode away concrete many times. High pressure steam is almost always invisible, so the "broom stick" method of leak detection is indeed a common method. Water hammer can be SCARY to say the least....even small slugs of water contacting steam can be quite violent and as seen in the video, can lead to catastrophic material failure.

 

[MossRoad]

I thought you were literally speaking of a steam hammer, and couldn't quite understand that.

Now, I get it.

But what of the flame and flash?

I went back and looked frame-by-frame and I think the orange flash is when the camera moves rapidly past a worker's orange vest. Looks like flames at full or even half speed.

 

[Egon]

If you listen to the video, you can hear a loud BANG every 5-6 seconds. That's steam hammer. Condensate has built up in the pipe to the point there's a water slug getting slammed down the pipe in a wave. The water runs back, forming a wave that blocks the steam and its again hurled down the pipe, drains back, plugs, is hurled, drains, plugs, hurls, drains, plugs, hurls.... eventually, in extreme cases, it can burst the pipe. If the steam pipe bursts, the steam reverts to normal water - violently expanding 1600 times its volume pretty much instantly. BOOM!

Might also be a steam trap venting.

 

[dadster4]

Might also be a steam trap venting.

It is steam hammer, but to clarify, the steam does not revert to water...the water in the line turns to steam when it is no longer under pressure due to a leak, break, or opened valve.
And steam traps do not vent to atmosphere or make more than a slight noise when activated.

 

[Egon]

It is steam hammer, but to clarify, the steam does not revert to water...the water in the line turns to steam when it is no longer under pressure due to a leak, break, or opened valve.
And steam traps do not vent to atmosphere or make more than a slight noise when activated.

Okay, I've been educated!

Others may follow this line of reasoning. Marmaduke Surfblow would probably agree!
[video]https://www.linkedin.com/pulse/whats-banging-steam-plant-part-1-traps-discharging-pumped-fidgeon[/video]

 

[MossRoad]

Might also be a steam trap venting.

Nope. It was hammer. We were shown this in class and the instructor had talked to some of the people involved.

 

[MossRoad]

It is steam hammer, but to clarify, the steam does not revert to water...the water in the line turns to steam when it is no longer under pressure due to a leak, break, or opened valve.
And steam traps do not vent to atmosphere or make more than a slight noise when activated.

You are correct on the part about water turning to steam when no longer under pressure.

We were told about cavitation in steam traps causing water hammer.

 

[MossRoad]

There's a good write-up on cavitation and hammer in this link...
- ITT-Residential and Commercial Water Solutions