San Bruno Pipeline Accident Update

Well let's see. A 30 inch dia pipe would have 30 times 12 square inches or 360 sq inches per foot of length. That times 400 psi would be 144,000 lb of force per foot of length or 72 tons of force per foot of length trying to rupture the pipe. That might be strong enough to lift one foot of pipe and the earth above it.

Dan

Reply: After seeing a steam line rupture in Oakland about 40 years ago, where it blew some of the street 15' from the hole, I would estimate that the high pressure gas carved a rather large hole in the ground on it's way to the surface. Then with the addition of surface O2 now mixing with the gas, you have the makings of a large FAE A large fuel air explosive. Also known as a big bomb. All it took was a spark to happen and we know that did occur because of the fire. The PG&E records thought it was a seamless pipe, but the pipe was vintage 1955 I think I read. So a bad weld, and some corrosion and 8 dead.

=========== Most unfortunately this appears true of all the trades, not just welding.

We are about to discover that you cannot operate a viable economy based on stock brokerage, financial engineering, web design and "academics." Someone has to keep the machines and infrastructure working and build new "stuff."

-- Unka George (George McDuffee) .............................. The past is a foreign country; they do things differently there. L. P. Hartley (1895-1972), British author. The Go-Between, Prologue (1953).

========= To follow up on my own post.

WASHINGTON, DC ? Why do Wall Street guys make so much more money than the rest of us? Income inequality is rising in the U.S., and the gap is sharpest among the super rich. A little of this is sports stars with outlandish contracts, sure. But a lot of it is the financial sector, Tyler Cowen writes at The American Interest. And that's troubling. There's the debate over whether these gaps cause financial crises. Then, though, there's also this question: How does the financial sector rake in all that dough to begin with?

• How Did They Get This Much Cash in the First Place? Mother Jones' Kevin Drum wonders.

There are three possibilities: (1) banks created it, (2) their activities caused the economy to grow faster than it otherwise would have, and they reaped the benefit of that extra growth, or (3) it was somehow skimmed away from the rest of society. Possibility #1 is unlikely: banks certainly created mountains of debt, but mountains of money would show in skyrocketing monetary aggregates and high inflation, neither of which happened. Possibility #2 also seems unlikely. There's simply no evidence, either in comparisons over time or comparisons between countries, that economic growth over the past two or three decades has benefited from financial rocket science. So that leaves possibility #3: somehow, all this financial engineering was based on skimming money away from everyone else.

-- Unka George (George McDuffee) .............................. The past is a foreign country; they do things differently there. L. P. Hartley (1895-1972), British author. The Go-Between, Prologue (1953).

Steve B wrote in rec.crafts.metalworking on Wed, 15 Dec 2010 22:27:52 -0800:

Pipe and tube are made from sheet, rolled and formed into shape. The weld is a resistance weld made similar to the way chain links are welded, but on a continuous basis.

See:

There is also a national defense element in what you forsee. The projection of US power will be greatly reduced in the future if we continue down the path of reducing our manufacturing capacity. This will result in downsizing our militay and free up the military budget. The money saved can be used for more bailouts.

Best Regards Tom.

Don't count on that happening. The solution to date when a system isn't reliable is to build redundant capacity. That's why we have so many nukes.

Yet another LA Times article:

(Does linking like this work better for everyone?)

Erik

"John R. Carroll" wrote

Can you weld?

Steve

(4) What they couldn't create in Space they accomplished in Time: CREDIT.

jsw

Erik wrote in rec.crafts.metalworking on Thu, 16 Dec 2010 18:05:19 -0800:

Nope, still wraps.

But by enclosing the URL; smarter clients can grok it.

Even in lowly Google Groups if I reply, edit it to one line and paste it into the URL box it works.

jsw

Darn few and far between are the fitters who get the weld symbols right.

Give us a clean, properly prepared, properly fitted joint, and you probably wouldn't have nearly so many issues with your welders. Every trade has it's asses, but the people who complain about others the most usually have the most wrong with their own workmanship.

The aren't part of the URL, and at least on my newsreader (gnus inside emacs) don't do a thing to prevent linewrap.

I tried for a while but they didn't always work, so I went to

jsw

You are describing a torch jockey, not a welding professional.

That might well be true but in the instance I had in mind when I originally posted I'd had to spend more that $100K to fix something done by a "professional". $250K in hardware went all the way to nearly $400 and the mess made was six months late when I was asked o look it over. I've got a guy here in Los Angeles that ordinarily welds the assemblies I contract to build. He's been around a long time. When I have a project to build, I design the fixturing, get started with the machining and then take a complete set of drawings over to him. We settle on the joint design, gas port locations, inspections and anything else necessary and I follow his guidance. I'll either do have completed the metallurgy and if custom rod is required, I'll have samples made and prepare test coupons.

Because my guy is an actual welding professional, the result is always excellent and I build prototype liquid fueled rocket motors and the high pressure hardware it takes to drive them for a living. I've never had a system fail in the field. Not even one. When last summer's science project was redelivered to the AF, several of the guys on site remarked that the rework had obviously been done by a professional that cared about quality from start to finish. In five decades AFRL Edwards has seen an awful lot of this sort of hardware. The welds were without flaws and the flanges on three assemblies each with three high pressure bellows in them were planar to within .005" over 70 inches and located to within plus or minus .003" of the print. They had never seen that........

I wasn't able to use my regular vendor for my "Summer Job" this year and had to contract with people I didn't know. Of the five people that welded test coupons, only one impressed me as being on the ball but they couldn't meet the delivery requirement.

In the end, I got the job welded up by a group at Lawrence Livermore. On of the guys is a "Double Dipper" and has his own shop. Great guy but I had to spend July holding his hand and that seemed a bit much. He had the welding down pat but not the rest of what was reqiured. I'll use him again, however, if he's up for it. I, for my part, learned a great deal about the welding business, however, and what I learned is that there is no such thing as "Welding" in the sense that most people think of it. Every type of work is it's own specialty and the trade is so lame that the people working in it are really just a bunch of specialists, not competent professionals in their industry. I also learned just how lucky I'd been to be able to work with the guy in Los Angeles over the years.

One last comment. I seriously wondered if I wasn't just being unreasonable in my expectations and since I had a month on my hands and real professionals to teach me, I learned to do this type of job. I took and passed a certification test supervised by liscensed examiner in

There is a guy that posts here from time to time. Lennie something or other. That guy is my idea of a real welding professional.

Are you anywhere near a naval shipyard?

jsw

I'm in San Diego today, so yes. I've also seen welds in process at EB Groton.

The guy who's work I "fixed" up was a Navy vet. I never met him but by all accounts, a nice guy. Bad hair day perhaps....

Do they teach people to leave their diffuser's in an assy. if they fusion bond in the Navy or was that self taught?? One of those things going through a cryogenic hydrogen pump operating at