A safety question for Steam

→ Steam Tables. The properties of the ice/water/steam system are well-documented and it is rarely necessary to conduct experiments to determine properties.

http://www.simetric.co.uk/si_steam.htm

At 276barg and 380degC, the steam is superheated, i.e. it is present wholly as a gas.

As to safety, what are the hazards: the container rupturing? Skin contact with it? Naked flames? Leaks from the fuel source that provides the 380degC? These things cannot be seen from here, so proceed with all due caution!

Why do you pump the water to 4000 psi?

If the pipe is already full, where will the steam go?

Won't the purge valve also release steam pressure?

What is the tube made of?

Will you use a safety relief valve?

Thank you PWSlack and TVP45.

I want the water finial point to be 380C and 4000psi. So i use a pump. If the pipe is already full, I will open the purge valve to release steam pressure. I will open it many times. That is :heat, open valve, heat again, open valve again.......

Tube is SS tube. I will not use a safety relief valve.

David

<...water...> does not exist at the specified temperature and pressure, as the review of a set of steam tables, as advocated above in #1⇑, will confirm.

<...will not use a safety relief valve...>

Then the materials and thickness of the <...tube...> need to be selected carefully so as to withstand the stated conditions.

Please ensure all other CR4 readers are at least 500m away before conducting this experiment.

No, I do not think this experiment is safe. Do you have calibrated temp. and pressure instruments? What if one was to fail during your experiment? The addition of a safety relief valve is recommended, not a real big expense, especially since it could save your life.

David,

The experiment is not safe! Steam tables will provide the relationship between the pressure and temperature of saturated steam. Steam pressure increases as temperature increases, there is no need to pump the pressure in.

Boy - David,

That just sound frightening to me. I don't think your liability insurer will trust it either as I was once in the insurance business. It kind of reminds me, of the old cartoon, where the Road Runner speeds off, as Coyote gets blown up .

If I tried it , I would pull that trigger from a safe distance , while hiding behind an Abrams tank.

Good Luck Brave Lad; Write us back afterwards and tell us you lived.

Best Regards,

Joe Woodall, Managing Partner

Georgia Adobe Rammed Earth & Renewable Energy

2395 Bowman Hwy. NW.

Dewy Rose, GA 30634

706-213-7693

www.georgiaadobe.com

Don't do it! If you have to ask the question, it's obvious you don't have a full grasp of the situation that allows you to do it safely.

Find someone with the experience to help you.

The first known use of steam was for a bomb. Put water into a vessel with no pressure relief valve, and leave it in the campfires of the enemy. Your experiment is very dangerous.

Don't do it. The process you describe later of heating, manually bleeding off pressure, heating , manually bleeding off pressure, is unsafe. At very least, you need a reliable relief valve (which will do the bleeding off for you). To be safe, this would need to be engineered, not guesstimated --otherwise you are creating a bomb, but hoping to keep it from exploding by bleeding off pressure at the right times. Perhaps if you described your arrangement more thoroughly, and explained what safety margins you've calculated for the pressure vessel at elevated temperature, as well as what safety precautions you've taken, then we could say if the experiment seems safe.

HOWEVER, what do you hope to learn that you cannot simply find in steam tables? Is it a psychological experiment to see if the subject has nerves of steel?

You are wise to ask if this is safe.

What on earth are you hoping to discover?

Pumping the water up to 4000 psi is up in the area of what a hydraulic system would operate. Now, you are going to heat the tube, thus weakining it (assuming your end caps hold). What wall thickness are you going to use? I don't think they make 1/2" tube with a 6" wall thickness.

If the tube is full of water, where is the steam going to go?

Do you know how to read a steam table? That will tell you everything you need to know about the steam at any pressure and temp. You can calculate the quality (if you don't know what quality is you really have no business doing much more than boiling water to make tea). Did you take Thermo 1 and Thermo 2?

In short, about the only thing you may discover is God when this thing explodes in your face.

Travis

David2008,

Aren't you above the critical point on the water?

Have you done an energy calculation on this badboy?

If you were able to get to this point, what would you do with this steam?

The more I think about it, this has to be a hoax. Nobody could be that stupid to try this.

If it's not a hoax, then I give a nomination for a Darwin Award.

Thank you all!

This is not hoax. I will not do that now. I should consider and design it again.

David

David,

Tell us what you're trying to do and we might have some suggestions.

DAVID <SLAP SLAP> WAKE UP! YOUR NOT LISTENING TO A SINGLE FRIGG'IN WORD WE ARE SAYING. DON'T CONSIDER AND DESIGN IT AGAIN! JUST GIVE IT UP! WHY NOT CONSIDER AN EXPERIMENT THAT WON'T KILL YOU, AND PERHAPS ACTUALLY ADVANCES SCIENCE.

At another facility of my company, a 4000psi line let go and 8 men were killed. I've seen a water jacket fail, and it's safety fail, resulting in an explosion that threw a 2 ton door 50 ft. Luckily nobody was hurt, but I was standing there just minutes before. Steam and pressure are nothing to play with!

David,

I agree with every post that your experiment would be LETHAL if you followed through. Even 15 psig steam is 250 deg F, and enough to turn turn that tube into shrapnel and simultaneously impale and create 3rd degree burns on the people standing near the explosion.

A couple of things:

1. Never directly inject superheated steam into water - think the steam main break in New York - it blew a full size truck 12' in the air and had steam plumes going up over 30 stories high.

2. Superheated steam is a poor transfer of heat energy - it is used to do work (such as steam turbines)

3. Think twice about injecting high pressure (non-superheated steam) into water as this can be dangerous too if the system is not properly designed.

4. If you are just trying to heat water so the hot water can be used for something else, then you may want to consider a heat exchanger (plate & frame, shell & tube, tank with a coil)...

Go to the following link to give yourself a crash course on the principles of steam & heat transfer before venturing back into your experiment.

http://www.spiraxsarco.com/resources/steam-engineering-tutorials.asp#block2