Welding a small pressure test vessel...

I have no experience with pressure vessel welding so I have nothing to add, just lots to learn.

I am not an experienced welder, but when I did my steel and stainless cert on 3/8" stock, I used a couple of different TIG machines both set at only about 120 amps. I made multiple passes and the process was slow, but both passed with no problems.

If the OP tapered the cylinder end so that he was certain to get full penetration and preheated the pieces, why wouldn't the machine he has suffice? I am not arguing here - just interested by your comment.

Peter

J.T., for God's sake the guy was talking about 150 psi.

If you've been doing this kind of work for any length of time, which I believe you have, I can't believe that you can't weld a piece of schedule 10, 8 inch pipe to a half inch plate and have it hold 150 psi.

Bruce in Bangkok (brucepaigeatgmaildotcom)

You seem pretty sure of yourself, and sure can talk a lot. But there's nothing to stop us from *doing*. The project at hand is a low use item. We should be able to agree to a reasonable number of cycles and test pressure. I've offered to let you make a serious profit from the ignorance you're so sure of. Your reluctance reminds me of all the people who swear they can dowse water, but for some strange reason aren't willing to demonstrate their skill for a million dollar prize.

Heard it all before many times. Slow death by fire, decapitation, etc. Same thing 40 years ago when I started riding motorcycles. I should have bet some of them that my head would still be attached 4 decades later. 'Course I wouldn't have made a profit because a naysayer never puts his money where his mouth is.

Wayne

Are you assuming that the only way to do it is to weld the pipe to a oversize plate with a fillet on the outside? That could certainly be strong enough, although if it were me I think I'd cut the plate to the pipe ID, leave the root a bit open, and fill the corner. Assuming a flat fillet, that would make the thinnest part of the joint about .35"

I qualify.

It's 150 psi, and 8.625" OD. About 323 pounds per inch of weld. Are you saying that there's some reason that the best welders you know can't build up a one inch long fillet you'd trust to hold 323 pounds? Then how come my own little quicky test tank, made from a 3" coupling with plating barely ground off, and single-pass fillet welded to 1/4" plate, can hold 500 psi, which is about 475 pounds per inch of weld?

Why write about soda bottles when somebody is prepared to build the actual item, spot you 50 psi, and let you make an easy 2 grand off your opinion? I'm sure we could run the thing through a couple hundred cycles in less than 2 hours including setup. Where else can you make $1000 an hour for doing nothing? Would it help if I upped the wager? I think you're as exactly sure as I am that your money would be moving into my wallet, but just aren't willing to admit it.

Wayne

I see what you mean now. Yes, it sure does look like the edge of a SIP. But it's actually one edge of a recess in the concrete that allows the hoist to be lowered below floor level.

Wayne

"Bruce" wrote in message news: snipped-for-privacy@4ax.com...

Right, 150 psi, I saw that part. The people who are high centered on the fact that they believe the material will hold the pressure and even an overpressure test are missing (my) point, they evidently think I'm missing theirs. But I'm aware of the 150 psi of pressure. My oxy acy hose will hold 150 psi (for a while), I'm pretty sure my garden hose would hold that much for a while. I think my kitchen faucet will hold that for a while. I've had my work (2500' of 18" line pipe) hydro'd to 1250 psi with nothing but a bead (root) and a fast hot pass. That pipe, as welded was not in any way fit for service, but it will hydro pretty high with very little weld. This was just to test the pipe for anomily repairs. I've got a bonehead understanding of what will hold what just from decades of observation. I've also seen systems on hydro for over 8 hours before letting go. Hydros are a funny and interesting thing. I'd have to think about it (and I'm not in the mood for that) but offhand I don't recall seeing any partial pen weld used in a pressure containment system ever, and I can't think of a fillet used for the same with the exception of socket fittings. I'm geared to the welding end of things and of course a partial pen fillet described just about does everything wrong. The mother of all notches on top of it all. You may be aware of all this, you may not care, but it's kind of interesting to me so I throw it out there. Like I said that's my take, take it or leave it.

Happy Mothers Day! JTMcC.

>

I did not say impossible, I said impractical.

TIG has its place and IMHO is the most elegant of all the welding arts, and capable of making the best quality (and nicest appearance) welds on the greatest range if metals. I am sure that the OP's machine could easily be used for stick SMAW which would be my preference for heavier work, however the OP's honest appraisal of his training led me to suspect he probably lacked the required skill set.

No disrespect to the MIG guys but IMHO a TIG box equipped with both TIG and stick attachments is the best and most versatile welding system. My use of TIG has been limited to thinner materials and most commonly for SS, Aluminum and CrMo. Welding root passes with TIG does require additional setup in order to provide proper shielding gas to the back of the root. I suspect that a metallurgical or welding engineer would also specify additional pre and post weld heating and stress relieving which I suspect would be necessary due to the increased number of passes, and increased total heat input (time), but YMMV. IMHE, TIG is a lot slower and IMHO requires a high degree of (mostly left hand) skill.

Just my .02, YMMV

I'm extreemly confident in the work we produce. If I wasn't I'd be in another field. Everything we weld will result in property damage, injury or death in the event of a failure. To be other than sure of yourself in my field is a "very bad thing". And I like to sleep sound.

But there's

Go back and read my replies, If you find one fact that's untrue I'll gladly retract the comment.

I never told the guy not to do it. I DID shed a bit of real world light from someone who does this work pretty regularly in a profesional setting. I'd of thought that might be handy but evidently not.

I wasn't aware that building an airplane made one a vessel engineer. I wish I had known, my Dad built more than one aircraft while he was at Boeing, and maintained many (B-47's, B-58's, B-52's, KC-135's, C-130's, F-100's, F-101's, F105's, ect) over the years. I could of recieved a cut rate on engineering fee's ; )

I'm pretty sure I've never told anyone in my life to not pursue dangerous exploits. But I have given fair warning many times. I tought quite a few young men and women to rappel years ago and I impressed upon every one of them that a fall from 100'+ was very likely going to be fatal and that is why we take our procedures and equipment serious. I never told someone not to sail off that tower, but they knew there were inherent dangers, what they were, and how to minimize them. Same with my welders helpers, I explain the hazards involved in the work we do, I tell them that people are crippled and killed every day in this field, but I've never told one not to do it. Everyone that's ever stepped foot in dangerous territory with me, has been made aware of the potential problems and how we intend to minimize them.

And I've been riding motorcycles since I was 10 and I've still got two, one a flat tracker, one an old 80" H-D. I've still got the climbing ropes, harnesses and hardware but it doesn't get used much anymore, every once in a while tho. I hung iron for years, and dropped out of the Ironworkers when osha stuck it's nose too deep in my life and the west coast went to 100% tie off. I started when IW's didn't tie off and they carried Budweiser in their boltbags ; ) I really don't believe the sky is falling but I do believe in people being aware. That seems to be a trait I see less and less of. It seems to be a usenet characteristic that hobby pseudo experts get very perterbed when people post on a topic they actually work in, shrug : ) I hope you hugged your Mom today.

JTMcC.

JT, yer a jewel.

Steve

I've always thought so. Probably one of those really tacky ones down at the pawnshop tho ; )

God gave everyone a sense of humor. I intend to wring most of the life out of mine before I tip over.

JTMcC.

"JTMcC" wrote

I just had my 5th heart cath ten days ago. You do have to laugh at this stuff. You don't get out alive, and some of it IS funny as hell.

Your mention of your IW days brought some memories back of when I used to work with my father-in-law doing derrick construction offshore. There was a program on the other night, and even an old old hand I used to work with was on that program. Those old boys didn't know what a tie off was, and considered them idiotic. If you're tied off to something and it goes, so do you. I worked it for a year and a half. In that time, I got one of my three USCG night time chopper medivac rides during the time I worked in the Gulf. A gin pole cratered in the top of the derrick, and knocked loose a lot of stuff. I looked up just an instant before a 5 gallon bucket half full of 7/8 x 3" bolts landed where I was standing. I dove over an air tugger and got a broken jaw and a separated shoulder. That was my last trip. I went back to diving. Then into welding full time. Iron workers are one tough bunch.

Keep laughing. It IS funny.

Steve

Not to get off track, but it's too late anyway. The last IW job I had was welding on an 80' pick board about 90' up on moment connections in the bay area and they had a small earth shake that made my long scaffold bounce up and down. I thought somebody had jumped down on it and yelled at them to stop it, but after looking around I figgered out it was the earth moving so I tied off to a beam instead of the handrail I had been tied off to :0) Later that day the safety lady came along as I was about to hop down onto my pick board after break, I was at the edge but not tied off and she gave me a little safety speech, I told her I was an IW and I lived on the iron and I was gonna run free till the day I died and I didn't need a nanny looking after my wellbeing but thanks anyway and have a good day. She reinformed me that there was a 100% tie off order in effect, gave me a little safety pin, and Bechtel laid me off the next day and that's when I decided to weld pipe full time and forget this neutered IW thing. It's worked out well, the pipeline seems to be the last refuge for folks like me, and pays more than anything else I can find.

I like that line: Keep laughing, it IS funny. I'm prolly gonna steal it ; )

JTMcC.

Very interesting story. I am curious how much does pipeline welding pay. It is one of those jobs that will never be outsourced to China!

i

Right now, and we are in the largest pipeline boom in living memory, a 798 (Union)Pipeline Welder makes $41.63 per hour, plus $25.00 per hour for his rig, plus $42.50 a day (per diem) plus a $16.00 benefit package (pension, health insurance, training fund). Our work season is about to begin in earnest around the first of June, after the rains end, and it will continue thru the new year. Any experienced pipeline welder on the planet will be working for as long as they are willing to stay out. This generaly means, on the standard 6/10 schedule that a welder will make about $4600 per week. This is very demanding work and not just another welding job but a job for expierienced hook 'n book pipeliners. But there aren't many (or any) places to make more money as a rig welder in the world. Welders helpers and experienced pipeline Journeymen are also going to be at a premium, any experienced individuals interested should contact the Pipeliners Local Union #798 in Tulsa, OK. The current backlog is large and in charge ; )

Have a Day! JTMcC, turnin an a burnin

Keep in mind the inspection is as harsh as any in the industry.

6G plus a 12 on 12 inverted branch weld test and 100% visual and X-ray after that, in a very fast paced high production enviroment. The question in pipeline construction is "how many miles did you go today?"

Some people excell in this enviroment but some melt down.

diffrent streaks for diffrent freaks : )

JTMcC.

My Dad (the best man I ever met or ever will meet, a stout paratrooper and a great aircraft mechanic/later instructor, 25 years actice duty service), who left this earth two years ago this month, had a great cardiologist, and lived many years longer than he should have, had more work done than you could imagine but he never lost his sense of humor and he enjoyed every day on this planet. It's a good thing what those doctors can do today.

JTMcC.

I was waiting for JT to weigh in on this before making comments.

The following opinions and comments are from my own experience: (don't try this at home)

I worked in the booming Gulf of Mexico for about ten years total. Worked a lot of pipelining, diving, and other things. I am nowhere as qualified or skilled as JT, but have a lot of real world experience. JT does it to this day, and I'm done. But, been there, done it, got the scars.

The major caveat I have is "lifestyle".

It takes a special person to endure it. Single people do better. It's hell on marriages. Old oilfield joke for welders and directional drillers is that when you hire on, they agree to pay your alimony. You are gone for months at a time. On one job, the conditions are great on one job, and on the next job, every portion sucks. Bad quarters, bad food, bad equipment. On land pipelining jobs, men a lot of the time can provide their own quarters, and for that money, can live in a nice travel trailer. I just sold a NICE 38' motorhome I delivered to a pipeliner in Albuquerque, and he paid CASH. On other jobs, or for other welders, it's a motel somewhere. Living out of a suitcase or seabag, working ten hours a day or more, eating where and when you can. You live in close quarters with a lot of people. Some of them are not anyone you would even associate with "on the beach", but now, according to job conditions, may have to share close quarters with.

But no matter how you cut it, it comes down to this:

EAT SLEEP WORK EAT SLEEP WORK repeated as long as you can stand it or keep your sanity.

You come to intimately know the term "bone tired." You come to intimately know what the term means to "suck it up and shut up." And before Larry The Cable Guy's "Get-R-Done", it was "Just get it." Meaning, do whatever it takes to finish.

My longest duty was 118 straight days of 12 hours or more. I had three days off, then 91 more. One day off, then 32. Eight months with four days off. All you do is work, sleep, and eat, and lots of times not the best any of the former.

I did some stints in Nigeria, but those were short platform hookups. Other guys I knew stayed a year on contract in the Middle East during quieter times, and that's living in a protected compound, and doing NOTHING but eat, sleep, work. But still, imagine eat, sleep, and work for 365 days. Takes a focused person. It tests you down to your core.

The upside of the deal is there is very good pay for pipelining. My step-dad worked all over the world, and for great money. He was a member of the Tulsa local. He died doing a hot tap at a power plant in Las Vegas. My uncle also died in that accident.

Downside is that it is a hard gritty job where you have to perform to specifications, or you're out. No matter how you feel physically or mentally. You're a pro, and that means you will do a good job no matter how you feel. You can't have repairs or cutouts. Long hours and hard work, and there's no other way to describe it. Effort and attitude doesn't mean a lot. Performance is what the man looks at.

As JT said,

Been there, done that. Can't stay away from Mama and the kids for long? Get a phone call where your daughter broke her leg, and can't go to see her? Miss every dance recital and soccer game? If you can't handle this long distance, advice: this ain't for you.

Life's a series of choices and tradeoffs.

You take what you can live with. It's a young man's game. Shit happens. People die. And people wear out and burn out.

No negativity intended, just hoping to shine a light from a different direction from an old worn out fart. It was grand adventure. I made some investments along the line, particularly in silver (early 70's) and real estate that paid off in gold and allow me to be retired at 58. (and that's lucky, because with my health now because of heavy mileage, I don't think I'll live to or much past average life expectancy)

It was a great ride.

Steve

"JTMcC" wrote

When I had my 5 way bypass , aortic valve replaced fire years ago, I said it was like getting two extra balls in the pinball game of life.

Looks like from last reports, I got some more time left, too.

Steve