UT or Magnatic Partical

Date 11-03-2000 08:32

Dear Sir,

Which method of testing is appropiate for online testing of ERW pipes. (as per BS 3059)
a) Magnetic Particle or b) Ultrasonic Test
(we don t have eddy current test facility)?

Kindly let us know which one is more depandable?

I would be highly obliged if someone could tell me how to remove internal fins after the welding.

Thanking you

With kind regards

Mukesh Agarwal

By - Date 11-04-2000 00:20

Magnetic particle testing is a surface testing method used to detect surface breaking defects whereas Ultrasonic testing is a volumetric testing method used to detect sub surface defects.

By NDTIII

Date 11-04-2000 03:09

Not neccessarily true. By ASME definition, it is a surface exam, however you can get some penetration even with AC current. It would depend on the thickness of the material under examination, but I think UT would probably be a faster and more sensitive method.

By G.S.Crisi (****)

Date 11-09-2000 12:31

Dear Mr. Agarwal,
As I told you when I answered your question posted on September 19 and titled "Cold drawn erw pipes", first thing you've got to do is to read the standard the pipe is made to, in this case BS 3059. Does the standard specify which NDT must be made? If so, it's not up to you to choose the kind of test, but you should follow what the standard says. However, if the standard leaves the option to the manufacturer, but only in that case, you can choose the method.
ERW pipes use to have internal fins. If those are unacceptable to you, then the only method I know to get rid of them is by cold drawing.
Giovanni S. Crisi
Sao Paulo - Brazil