San Bruno Pipeline Accident Update

Hi all,
Sorry for the long URL.
http://latimesblogs.latimes.com/lanow/2010/12/ntsb-reports-sections-of-se am-on-exploding-san-bruno-pipeline-were-welded-only-on-outside.html
Erik
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I copied and pasted this url, and it worked for me. The second one you posted said OOPS, broken.
This is interesting.
VERY FEW pipelines are welded both inside and outside. Most are just welded on the outside, that being a confusing term. They are welded FROM the outside, but the root pass penetrates into the inside of the pipe a tiny bit, and joins the root of the two pieces together. Very few pipelines are welded on the inside because it interferes with the cleaning devices run through them. That would be for the welds that join the two pieces of pipe together.
The article was about the absence of longitudinal welds, that is the welds running from end to end, made when the pipe was rolled into a tube, and the edges joined along their two longitudinal edges. The welds are then finished so fine that it is difficult to find the weld. Apparently, the sections of pipe had longitudinal welds that had inside and outside welding, but some were missing the internal half of the weld. There would be major inconsistencies if they were present in some sections, and not in others, or were intermittent, as from a malfunctioning welding machine. I would suggest that they were made with an automated welding device, perhaps using the SAW technique. (Submerged Arc Welding)
It will be interesting to follow this. This particular fact of the investigation is one that I would have never guessed. I always said I'd wait for the final report, and this isn't even the final report, but it DOES provide some of the actual facts of the metallurgical forensic investigation.
Steve
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Steve, this is very useful to know. DO you know if that one "outside" weld that leaves a root inside, is done with one pass?
i
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On Tue, 14 Dec 2010 21:15:02 -0600, Ignoramus21697

Certainly. I visited a pipe plant in W. Java that made spiral welded pipe ranging from 12 inch to 36 inch, with a maximum capacity of 48 inch. An Australian based company had built the plant and were in the start up phases when I was there. All of their pipe was welded single pass using a submerged arc system.
You could see the weld on both the inside and the outside and as I recollect that was the first stage in inspection - look to see if it was a continuous weld on both sides. Cheers,
John D. Slocomb (jdslocombatgmail)
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J. D. Slocomb wrote:

Yeah, It's caled Plasma Arc Welding. This technique has been in use for more than three decades. Root, Fill and Cover are completed in a single pass.
This method obviates the need for jackass welders.
--
John R. Carroll



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message

Plasma Arc Welding is _not_ the same as submerged arc welding. Sub-arc kicks plasmas butt to hell and back. Jackass weldors will kick your jackass too j. carroll...... Phil Kangas, an old 'jackass weldor' now retired......
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Phil Kangas wrote:

Technology moves on. My point was, and is, that getting the human out of this process is the best move anyone ever made.

I have yet to meet a welder that didn't need his hand held like a small child. I even have to do the fixturing, joint design and metallurgy these days. Luckily, I got a crash course from a group of people that are just nearing retirement - at age 70.

Retired.... The really good American guys are nearly ALL retired these days. ASW says there is a shortage of 200,000 qualified people right now. I don't know if I believe that number or not but there is definitely a shortage. One place you can still find people that know what's up is in the old Soviet Union. I can't send them my stuff or I would. They can't make a decent bolted flange to save their lives so they just weld everything.
The new START treaty forbids the retasking of existing ICBM's for conventional warheads and the Pentagon says they would be better off to build new hardware anyway. What I'm wondering is where they think they will find competent and qualified people to do the welding. The guy I use just cleared sixty and tells the same story others do. The trade (TIG especially) hasn't been passed on to the next generation.
--
John R. Carroll





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On Thu, 16 Dec 2010 00:39:28 -0800, "John R. Carroll"
<snip>

<snip> ==========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).
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On Thu, 16 Dec 2010 10:57:49 -0600, F. George McDuffee
<snip>

<snip> ========To follow up on my own post.
http://news.yahoo.com/s/atlantic/20101216/cm_atlantic/whydoeswallstreetmakesomuchmoneyanyway6213 Why Does Wall Street Make So Much Money, Anyway? Elspeth Reeve Elspeth Reeve Thu Dec 16, 9:25 am ET
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? <snip> * 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. <snip>
-- 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).
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On Dec 16, 12:43pm, F. George McDuffee <gmcduf...@mcduffee- associates.us> wrote:

(4) What they couldn't create in Space they accomplished in Time: CREDIT.
jsw
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Can you weld?
Steve
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snipped-for-privacy@hotmail.com says...

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.
--
Tin Lizzie
"Elephant: A mouse built to government specifications."-Lazarus Long
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TinLizziedl wrote:

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 304/308/316 SS pipe/3/8 wall up to 4" diameter in any position as well as SS to 625 Inconel. I'm still not a welder, which makes me about as qualified as most guys sporting paper.
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.
--
John R. Carroll

'Export Notice: This Document may contain Export-Controlled Technical
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Are you anywhere near a naval shipyard?
jsw
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Jim Wilkins wrote:

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 2900 PSI would be a bit messy.
--
John R. Carroll

'Export Notice: This Document may contain Export-Controlled Technical
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snipped-for-privacy@dev.null says...

There are welders of all stripes in naval shipyards, some taking their responsibilities more seriously than others. The best technical welders are the nukes with a nuke pipe seal welding qualification. They are specialists in tigging pipe by hand or machine, and often forget how to set up the equipment for other processes.
In my opinion, the best overall welders are those who take the extra time and care to ensure the assembly stays straight, using whatever process is most efficient for the position, length, and size of weldment. They verify the requirements for tolerances, material types, welding electrode and wire type, system cleanliness standards, and customer expectations. They produce a weldment that will pass whatever post-weld inspection the customer wants, be it VT, PT, UT, RT, MT, or ET.
I've met welders in the shipyard that have to be told time and again that their welds don't pass VT because of undercut, rollover, concavity, what-have-you. They don't get tasked with critical welds, and I've spent lots of time over the past seven years cleaning up after them.
I've met welders who take ownership of and pride in their work and these are the people I enjoy either following on a job or getting to work side-by-side with and learn from.
Please don't paint us all with the same brush.
--
Tin Lizzie
"Elephant: A mouse built to government specifications."-Lazarus Long
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I would guess that production weldors are specialized. One would weld submarine pipes for years, the other would TIG weld tiny stainless tubing pieces, the third one would MIG weld ladders or whatever they are called in the marine world, brackets etc.
i
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Ignoramus7337 wrote:

There is some of that but what he's really saying is that people's work product is a reflection of their character and integrity an abundance or shortage of either isn't industry specific. Both are individual qualities and when in abundance, are expressed in group efforts. I wouldn't disagree with that and to bring this conversation full circle, what failed in San Bruno wasn't the pipe or the weld. The explosion was a direct reflection of the integrity of the responsible party/parties or lack of same. Focussing on the technical only distracts from the underlying problem.
--
John R. Carroll




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On Sat, 18 Dec 2010 10:41:16 -0800, "John R. Carroll"
<snip>

==========An oldie but a goldie:
Pick any *TWO* (1) good (2) fast (3) cheap
-- 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).
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On 12/18/2010 10:45 AM, F. George McDuffee wrote:

To expand that a bit:
A good fast job won't be cheap. A good cheap job won't be fast. A fast cheap job won't be good.
Jon
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