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  1. #11

    Default Re: 6010 and 7018 rod for pipe

    Originally posted by azgorilla
    Just read a reply from HAWK that stated 6010 1/8 inch rod for first pass, then followed with 7018 1/8 inch rod for filler and cover pass, is the acceptable way to do a pipe weld cert. test. To my understanding, (in the field, natural gas pipe) you are to use 6010 rod, all the way out to the cap weld, using 100% downhand (downhill) welding. 7018 rod would need to be done vertical (uphill). Any feed-back from you experienced pipe welders?
    5P+ (6010) is the most common rod used on beads (the root pass) but 7010 and 8010 are used on some pipe. Fill and cap are sometimes done with 6010 on lower grades of pipe but much more common is 70+ (8010) and sometimes 7010.
    As for the size it depends on the pipe size, anything from 3/32" to 3/16" rod is used for beads, 5/32" is the most common on large line pipe, followed by a 5/32" or 3/16" hot pass, and 3/16" fill and cap. There is a downhill 7018 made for pipe, and it's used on some grades of pipe. All of this applies to downhill pipe welding.

    JTMcC.

  2. #12

    Default

    [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.

  3. #13
    Join Date
    Feb 2006
    Posts
    3,711

    Default

    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.

  4. #14
    Join Date
    Sep 2005
    Location
    Salem ,Ohio
    Posts
    3,897

    Default

    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

  5. #15

    Default

    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.

  6. #16
    Join Date
    Feb 2006
    Posts
    3,711

    Default

    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.

  7. #17
    Join Date
    Nov 2003
    Posts
    3,029

    Default

    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
    .

    *******************************************
    The more you know, The better you know, How little you know......

    “The bitterness of poor quality remains long after the sweetness of low price is forgotten”

    Buy the best tools you can afford.. Learn to use them to the best of your ability.. and take care of them...

    My Blue Stuff:
    Dynasty 350DX Tigrunner
    Dynasty 200DX
    Millermatic 350P w/25ft Alumapro & 30A
    Millermatic 200

    TONS of Non-Blue Equip, plus CNC Mill, Lathes & a Plasmacam..

  8. #18

    Default

    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.

  9. #19
    Join Date
    Nov 2003
    Posts
    3,029

    Default

    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
    .

    *******************************************
    The more you know, The better you know, How little you know......

    “The bitterness of poor quality remains long after the sweetness of low price is forgotten”

    Buy the best tools you can afford.. Learn to use them to the best of your ability.. and take care of them...

    My Blue Stuff:
    Dynasty 350DX Tigrunner
    Dynasty 200DX
    Millermatic 350P w/25ft Alumapro & 30A
    Millermatic 200

    TONS of Non-Blue Equip, plus CNC Mill, Lathes & a Plasmacam..

  10. #20
    Join Date
    Jun 2007
    Posts
    12

    Default

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







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