ERW Pipe vs Seamless

ERW or seamless--X-Ray it

CS and SS?--- Magnetically couple 2Coils with Pipe in between. A second check if there is doubt whether CS or Magnetic SS---:

CS will shield more than identical thickness SS.

mm

Thanks

I was trying to avoid RT on the pipe if possible...have you ever done chemical etching?

1.seamless pipes-

a.checked the thickness on every area is same by eddy current, ultrasonic testing m/c.

b.ovality(od+ wt) is in close tolerance.

c. it is carbon/alloy/steel 3types.

d.its bright & smother.

e. its in inch & mm both.

Ambiguity abounds...! I'm not quite sure what post #4 was trying to spell out (in apparent shorthand format). As far as xraying (1), it has been my understanding that xray won't divulge an ERW seam unless there are any discontinuities to be found (which are rare).

Thickness testing (UT) can sometimes tell if a pipe is TRUE seamless, because occasionally, the pipe comes out thicker / thinner on opposing halves.

Eddy current cannot be used for thickness testing (although in some cases it CAN be used for thinness testing (on very thin sheet). HOWever, eddy current testing IS the method of choice for locating an ERW seam. By calibrating on the pipe itself, then searching around the circumference of the pipe, the seam will be located due to the difference in permeability and conductivity at the seam. The displayed vector voltages will "tilt" (±15°) at the seam, compared to the remainder of the pipe.

This is how we locate the seam for subsea hot-taps, to insure that the bore hole does not land on the seam (of ERW pipe).

Best wishes ~

Thanks for the insight into the eddy current vs RT...is there a standard you can reference for the sub-sea hot taps that I can review and pass on to my NDT teams, or is this a common practice in the industry?

Though there are several ASTM Standards pertaining to relevant Eddy Current examinations {e.g., Seamless and Welded Tubular Products, Austenitic SS and Similar Alloys [E 426 (2003)], Eddy Current Sorting of Ferrous or Nonferrous Metals [E 566 (2004)] and [E 703 (2004)]} ... I am not aware of a Standard having been authored specifically for ERW seam location.

I was taught the technique by a highly respected peer (not sure whether it is appropriate to divulge his name or employer in this context), and, armed with that knowledge, I subsequently wrote our Company Procedure based on the fundamentals of the Method. There's no earth-shattering trick to it; anyone holding certification in eddy current testing, with the ability to understand the aforementioned Standards (as well as my previous post) can readily duplicate the effort, I assure you.

Best regards ~

Thanks for the advice...I'll try it out.

maybe you can answer another question that I have...

I have cast "swages" which are basically 6" nozzles on air coolers with a flange on the end...they are cone shaped, about 3/4" thick, and I'm being told that there is really no way to determine wall thickness due to the discontinuities in the cast steel. Profile RT is the method that I was recommending from different angles followed up by UT to confirm thickness. Can you recommend a better method?

Perhaps I'm not seeing the whole picture ... but, I cannot imagine why (given a suitable mandrel for holding & rotating) you could not achieve 100% circumferential accuracy in UT gauging using a focused-beam immersion probe ... unless the inner and outer surfaces are too far off-parallel.

Once the correct frequency is determined, and the focal length (in water) is calculated for your probe ... and the velocity/focal change is calculated for the material (nozzle) velocity, you establish your "Perpendicularity" (of the transducer) to your test entry-surface by obtaining the highest amplitude echo from the entry surface, and then, you're "home free" ...

Admittedly, my personal experience with castings is limited, and you may in fact identify numerous inclusions or anomalous measurements due to grain characteristics at certain points. But, backwall echoes (thickness gaugings) should certainly be obtainable ... again, given sufficiently parallel inner/outer surfaces.

Alternatively ~ could you not come-up-with a combination of inside & outside "custom calipers" or micrometers that would provide the measurements desired?

Thanks

To use a caliper, the nozzle would have to be disconnected from the associated pipe and the pipe moved...the other end of the swage is welded to a header box with no internal access. It could be done, but not cost effectively.

Imagine a box header that is 10" x 10" x 15"-0" long with the wide part of the swage (the bottom of the cone) welded to the box on the top...the ID at that part of the swage is about 4", wall thickness about 3/4". The top of the swage is welded to a 6" 300# flange, again about 3/4" wall, which is connected to associated pipe.

Could you recommend an external method to determine wall T?

I think I'm missing something about the tubing. In my experience a simple visual inspection has been successful. Seaming leaves a heat mark the length of the tube. If I'm misinterpreting the situation please tell me.

if existing insulated pipe in the field is ERW or seamless...CS and SS?

I am assuming an ID visual is not feasible.

cr3

My bad ....... didn't read carefully enough .............. guess i was missing something.