6010 and 7018 rod for pipe

[aametalmaster]

HAWK,
I took the 6G test on 6" pipe 1/2" wall, 1/8" gap, pipe beveled to a 45 with no flat. Allowed 3 tacks, 100 percent pentration with no burn thru or undercutting on inside of pipe. Decided it was time for a career change I got tired of the inspector's face reflection in my helmet he watched every move. He could not understand why it took so long to weld up. I asked him how much he welded he said "never struck an arc" go figure. Took a job across the road in the operations part of the refinery. 25 years of welding was enough. Now I own my own company and play on the side..Bob

[HAWK]

aametalmaster,

That is exactly how I got my first paying pipe job. 12 guys failed the 6G uphill test on 1" schedule 40 and I was asked to try it. We were suppossed to to all 6010 uphill progression. One of the local union guys wanted to see who was watching what. He did a 6010 uphill on half a dozen roots and then capped uphill with 7018. The inspectors never blinked. On 1" schedule 40 there usually is no fill pass. The root is usually flush with the pipe. I am sure they noticed, but probably didn't not care as long as the pressure test passed: 400PSI @ 24 hours. These lines were only put into use for 90-100PSI continuous service for natural gas.

Uphill 7018 should not be too taxing except for the "good" possibility of not burning in the root depending on the wall thickness. I tested once on 6" schedule 160 with 1/8" 7018 A-1 and had to be persistent to get the burn in.

[aametalmaster]

It may be done both ways except at the Marathon Ashland refinery in Canton Ohio. There its uphill all passes with 7018. Their rules it's their refinery. The inspector took a page from this book and another page total of 4 pages and made their own law. Sucks but that's what they want. 20 guys could not pass the test because they were used to a 6010 root downhill. Bob

[H80N]

JTMcC
so if I read you correctly you are saying that it is done BOTH ways and not neccesarily that the other fellas were full of.. er..beans...
thanks
Heiti

[JTMcC]

My "position" is simply this (for about the third time now) heavy wall, high pressure pipe is welded every day downhill. There isn't anything hard about this, it's a fact.
When you turn up the natural gas furnace, use your gas stove, or take a shower and enjoy the hot water from your gas water heater, you are taking advantage of the fact that welders have made several million downhill welds on cross country pipelines and the compression stations that push that gas to your town. On pipe, much of it heavy wall, and all of it high pressure. You don't have to believe if you wish not too : )
These historical facts are just that, facts. Really I wouldn't make such a thing up. And no WPS on the planet can prove to you my "point".
I am a UA member by the way.
And we do this work, high pressure piping, both down and up, mostly down in my case, on a regular basis.
Please don't take offense at anything I say, I'm only trying to put accurate information out on work we do daily, take it for what it's worth, and believe whatever tickles your fancy.

bye,
JTMcC.

[H80N]

Scott
of course there are!!!... was just trying to find out why this fellow so vehemently objected to what HAWK and others had said.. and thought any documentation to support such a strong stand would have been presented in a flash.. would be happy to read any other WPQ's and WPS's that are out there.. but as of right now.. all of the "FACTS" that I have seen.. seem to suggest that this might be his personal preference rather than formally accepted method...
hope that clarifies a bit
thanks
Heiti

[scott]

H80N i believe there maybe more wpq codes than the ones UA are showing..
thanks Jim

[H80N]

JTMcC
have me a little lost here..the specs (WPS) tend to be pretty specific..
and your nebulous answer has me a little concerened.. if you will bear with me.. here is a link to recognized pipewelding Qual tests

http://www.ajtraining.org/weldtestspecs.html

and the pertinent (SMAW) tests do indeed specify style of welding..
could you clarify please?

thanks
Heiti

[JTMcC]

Well it's just a fact, heavy wall pipe (1" plus), in high pressure applications is welded every day downhill, as well as up. A lot of people will dispute that, based, IMO, on published information, but we do it regularly.

I have a 3 ring binder in my truck with over 50 procedures in it (as required by law), but I don't think any of them will shed light on down vs. uphill pipe welding as they don't indicate the use or pressure of any final product.

I don't see any safety issue, no one is going to spec a high pressure piping procedure cuz they heard something on the internet, from some guy they never met : ), they will probably use the appropriate code.

regards,
JTMcC.

[H80N]

JTMcC
I am not a pipewelder but very curious about why you are so vehement... can you give us a Welding Procedure Specification that supports your position... this could be a matter of safety so we might all benefit from your knowledge..
thanks
Heiti

[HAWK]

JTMcC,

Hats off to you. It is obvious you do more pipe than I being the owner of a small pipe welding business. Pipe welding is not my main business. I typcially do 10,000' or less of 14"-30" and 3000' or less 1"-2" per year. Most of what I do is low pressure application. As for the procedures I have listed is what we have to follow even on thin wall low pressure piping.

The information I have posted and you disagree with comes from K.E. Bergman. They are an international piping and bellows firm. A family member has been welding pipe for 40 + years and is currently employed by this firm. This individual and the companies he has worked with is how I learned to weld pipe uphill and downhill travel.

As for our disageement I have none. I too am only speaking with what I am familiar with and the procedures we must follow where I weld.

We are both speaking from experience. I thank you from informing me of how things are done more recently. The techniques and application I am familiar with are older procedures from the 60's and early 70's and the limited areas where I currently work with pipe.

Again thank for the updated information.

[JTMcC]

Originally posted by HAWK
JTMcC,

Welcome to the forum.

Let me elaborate a little on my previous post from which you have posted as "quote". There are other factors that play a role in pipeline pressure ratings in addition to the weld travel position. However, I would rather make some generalized statements concerning the trade rather than delve head over heels into specifics: diameter, wall thickness, joint design, joint preparation, electrode type, electrode diameter, position of weld ( different than direction of travel), weld current changes during the process

Downhill vertical welds are very fast and very common on pipe of 1/2" wall thickness and less.
It does require higher currents and faster travel speeds than uphill travel. Closed roots are common with this procedure.

Uphill travel is slower because the current is lower to avoid puddle roll out. This method of welding creates an extremely liquid puddle which is more apt to melt out gas holes. These welds are more common in heavier walled pipe. The slower travel creates a heavier more defined penetrating bead. Inherently these beads are more easily able to pass radiographic high pressure requirements.

Uphill travel is more common where high temperatures and pressures are found such as in power plant or petroleum refineries. Common sense will tell us heavier walled pipe will withstand higher pressures and temperatures than thinner walled pipe. Since uphill travel is the preferred method of welding these pipes many engineers spec the same process for smaller thinner diameter pipes used in high pressure applications.

As the owmner of a small pipe welding company for over 13 years, I have to disagree with just about every thing you say.

Where did you hear or read of the 1/2" or less? We regularly weld pipe over (sometimes WAY over 1/2") .620 wall, .820 wall, 1.000 wall and 1.125 wall pipe are commonly welded downhill.

Uphill and downhill, are in my experience very similar as far as speed goes. I base this on time and motion studies done personaly, to determine time spent per weld. We time just about everything we do, to make future bids easier. Downhill and uphill are equal in terms of speed of welds made.

Your comments on what engineers spec, doesn't jive with our real world experience. How much pipe do you do in a year? We do a lot, in many different enviroments, your comments just don't correlate with my experience.

Where in a powerhouse or refinery (and I have worked in quite a few of both) are pipe pressures higher than coming out of a natural gas compression station?

I only comment on work I am familiar with, and do regularly, and my remarks on down vs. up reflect that. I stand by them .

JTMcC.

[aametalmaster]

Where I work we can't use 6010 for pipe. We have to use 7018 up hill root pass with a 1/8" gap. Then a 7018 cap up hill.. Bob

[HAWK]

JTMcC,

Welcome to the forum.

Let me elaborate a little on my previous post from which you have posted as "quote". There are other factors that play a role in pipeline pressure ratings in addition to the weld travel position. However, I would rather make some generalized statements concerning the trade rather than delve head over heels into specifics: diameter, wall thickness, joint design, joint preparation, electrode type, electrode diameter, position of weld ( different than direction of travel), weld current changes during the process

Downhill vertical welds are very fast and very common on pipe of 1/2" wall thickness and less. It does require higher currents and faster travel speeds than uphill travel. Closed roots are common with this procedure.

Uphill travel is slower because the current is lower to avoid puddle roll out. This method of welding creates an extremely liquid puddle which is more apt to melt out gas holes. These welds are more common in heavier walled pipe. The slower travel creates a heavier more defined penetrating bead. Inherently these beads are more easily able to pass radiographic high pressure requirements.

Uphill travel is more common where high temperatures and pressures are found such as in power plant or petroleum refineries. Common sense will tell us heavier walled pipe will withstand higher pressures and temperatures than thinner walled pipe. Since uphill travel is the preferred method of welding these pipes many engineers spec the same process for smaller thinner diameter pipes used in high pressure applications.

[JTMcC]

[QUOTE]Originally posted by HAWK
[B]azgorilla,
However, the direction of travel depends on several common variables: OD, Schedule, pressure, and the WE who wrote the procedure. Downhill travel is typically faster, but may require more passes and will not withstand the higher pressure tests that uphill travel can. Uphill travel is slower, requires fewer passes, and will withstand higher pressures.

I definitly have to disagree with this. Downhill is in common use on pipe over 1" in wall thickness, well over 2000 psi. Line pipe is the material of choice in pipeline construction, schedule pipe isn't. Speed, in my opinion, is roughly the same, and I have timed a lot of welds on a lot of different sizes of pipe, both uphill and down. Weld progression has nothing to do with the pressure that a piping system will contain, several other factors determine that.

regards,
JTMcC.