Question about Invar

I suggest that you do a google search.

Suppliers are found here.

Invar has a long use as a precision instrument material. It has been used at cryogenic temperatures in some telescopes for the low thermal expansion behavior.

I think that the use of Invar in your case may well be a "Pipe Dream".... it is a fairly costly alloy.

It is not produced in large tonnages for large structural use....

The advice given you is likely to have been narrow minded, solving one small part of the problem and giving you many other headaches.

HOwever, that kind of advice is easy to get.

There are certainly bound to be much imporved engineering solutions to this problem, but the lazy way is to "Find a MAGIC material".

There are several subgrades of Invar, just to make the problem a little more difficult.

My suggestion is to make some telephone calls to Invar people listed in the link above and get some direct technical information from them.

More accurate than USENET, usually.

Oh, you could email them which will frequently get only modest response.

Jim

Invar is a nickel-iron alloy which is ductile, weldable, and machineable.

Thermal contraction

Invar pipe and tubing is used and manufactured, but I don't know whether anyone stocks something that meets your needs. Google has hits on "invar pipe". Search the Thomas Register for invar.

For what it's worth, stainless steel is commonly used in cryogenic applications like liquid helium transfer lines which, at 4K, is a lot colder than LNG. But that involves relatively short lengths. I imagine an industrial setting could have long pipe lines where contraction would be significant. Metal bellows might be used to relieve stress, but a 36" diameter bellows is a big bellows.

You can't afford it for this job. Call someone that has already built one and see how they solved the problem and go from there. Strength at low temperature is going to be a lot more important than expansion. You can design for expansion and contraction you can't design for brittle failure.

Gordon

I don't suppose that aluminum/lithium alloy used in the hindenshuttle's center tank would be cheaper..

but it might be..

how much of a pounding is this material going to experiance I wonder..

would titanium work? I've never worked with crygenic friendly materials before.. and I'm interested in this discussion.

Why would it be an excellent idea to use the LIGHTWEIGHT aluminum tankage of the Space Shuttle for a terrestial application where weight is no noted object of concern?

Spacecraft tankage and large earthbound pipelines are like apples and oranges. They both may be fruits, they both may be fluid containers, but that doesn't mean much.

Look, I'm questioning the reasonability of your "arguments". Anybody can play the "WHY DON'T THEY USE _ _ _ _ _ _ _ _ _?" game.

There are people who have actually been paid to think about these problems for solution, and they have probably thought of a lot of stuff and analysed it.

Throwing out random suggestins is fun, but not a particularly intelligent way of unraveling the actual issues.

The entire problem area was suggested by a common simple-minded request to find the "MAGIC MATERIAL" that solves the thermal expansion problem, so that the problem solvers don't actually have to think.

And too many responses here are those that have only a few seconds thought behind them.

You could do about as well with a 10 minute "Brainstorming" session of people who have never solved this kind of problem, and have no or very little experience in the subject area.

Jim

Yeah! And how about NEUTRONIUM? Or better yet, UNOBTAINIUM!

Nah, OP should just use platinum; lots and lots of platinum. Thick platinum pipes. And don't forget to tell us where it is being built, so we can come a see it.

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BumHwan:

Any recommendation for service has to come from a combination of a design and a suitable material for constructing it.

I suspect this recommendation came from someone having seen a Nickel magazine article on Imphy's Invar M93 and the Gaztransport Technigaz tanker design

that thin Invar sheet has been used for the membranes in this type of double wall storage tank rather than corrugated stainless steel. For this particular design flat Invar is easier to fabricate than corrugated stainless.

For more information on other steels for cryogenics go to the home page,

and look under Technical Support, point to Applications, then click on Cryogenics

You will find Publication 410 on Invar, 313 and 4368 on austenitic stainless steels, and 1208, 1232, 10030, 14037 on 9% nickel steels.

9% Nickel steel has long been known to be suitable for LNG tanks. Some 5000 series aluminum alloys also have been used for welded tanks.

Alloy steels with less than 9% nickel don't work, as shown by the 1944 Cleveland disaster where a cylindrical tank of 3.5% nickel steel containing 6200 cubic meters of LNG failed the first time it was filled. LNG ran through the sewer system.128 people were killed, 300 were injured.

Pittsburgh Pete

--------------- DISCLAIMER

We don't believe what we write, and neither should you. Information furnished to you is for topical (external) use only. This information may not be worth any more than either a groundhog turd, or what you paid for it (nothing). The author may not even have been either sane or sober when he wrote it down. Don't worry, be happy.

weight

What does weight have to do with anything?

So what. Go with whatever is cheapest and most practical.

Because people enjoy the exchange of ideas. I indicated that I'm not an expert, and I'm just an curious bystander. I want to learn more. If you have a problem with that, tough!

In otherwords you are saying that you don't get along with people very well.

problem,

You're directing your rage at the wrong person pal.

If you don't like it, too bad. Start your own moderated forum.

Goodbye

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Your posting title describes you well. Just firing off "materials quips" ansd snippets from net browsing.

aSkeptic wrote:

Lithium Aluminum is far far from cheap. And, it is less easy of abricate (more expensive) than conventinal aluminum alloys so it qualifies as "Less Practical".

But you knew that, surely.

You like to suggest "New" things as solutions to problems which don't require them. It shows off what little in depth knowledge and experience you appear to have.

There are folks who like to "pretend" that they are informed individuals from reading small blurbs of recent developments, but who have little honest knowledge in a specialized field.

I am not claiming that you are that kind of person, but you do have the atrributes of one.

ok

I will shut up more

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If you want to be able to contribute more knowingly, here are a few suggestions. Almost All from Amazon.com ...

These would be good for many of the "Materials As A Hobby" individuals as well.

Materials and Design: The art and Science of Materials Selection in Design by M F Ashby

Ultra Light - Super Strong: A New Generation of Design Materials by Nicola Stattmann

The New Science of Strong Materials or Why You Don't Fall Through the Floor by James Edward Gordon

Engineer to Win: The Essential Guide to Racing Car Materials Technology or How to Build Winners Which Don't Break (3747ap) by Carroll Smith

Engineering Materials: Properties and Selection (7th Edition) by Kenneth G. Budinski, Michael K. Budinski [ Used for as little as $15]

Materials Science and Engineering : An Introduction by William D. Callister .... used for as little as $5

Foundations of Materials Science and Engineering by William F. Smith, William Smith [Older editions as little as $15.00]

Carroll Smith and J E Gordon are particularly readable. M F Ashby and his view of materials selection will provide you with an insight and overview that you will find nowhere else. Gordon's other books are really good and a little repetitive to his first one.

Ashby has some older textbooks that are indeed excellent as well.

you should post that on wreck.bicycles.tech as well.

those are really cool links! thanks! Might be able to find these at my local univ lib

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More advanced texts are often much drier an humorlessness is pretty much the norm, then.

JE Gordon and Carroll Smith are worth rereading over and over. Humor and realism make for this. Look for more Gordon in the library, it is worth it to read his better illustrated later books, if they have them.

There are some good serious books on the ASM International book site...

[free newsletter]

[ over 1,000 book titles devoted to materials things] Not much really "Fun", but they do sometimes have great sales on older titles and it is hard to resist building a library inexpensively that way..... but it isn't a few dollars per book.

You nevr know, you could be on the path to a new career.

Jim

I always buy S/H copies of JE Gordon, whenever I see them. Then I hand them out to people who'll otherwise ask me questions. It's a lot less effort, and some of them even learn something.

I've read Gordon, I think I got the recommendation from right here, some years ago. I was willing to put up with him because I wanted to learn something about materials. I had no idea that the subject could actually be entertaining. Quenching swords in urine is a technique that I shall never forget.

, Giving books away.

Is that your generous and sharing nature?

Or is it how sick and tired you become of people completely misunderstanding the whole subject of materials?

Or, something else?

thanks for the book links. I will cross check those from alden library when I have a moment. I am always interested in materials selection guides. Right now I'm preparing my garage so that I can do some gas torch welding. Materials are fun!

-Scott

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Daimmm aig heads. Think they knows ev'thang. Lordin' it over us workin' slobs that makes thangs fer real.

The situation is hopeless but not serious. ;-)

Cheers,

Phil Hobbs