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2455 views
01:20 Oct-06-1998
Michael Triniad
Thin walled (1.5mm) Welded Stainless Tubing

Some time ago the question was posted concerning the inspection of welds in thin walled tubing. I cannot recall if the tubing was stainless steel or not and cannot find it here in the archive for perusal. Therefore what would be best suited for inspecting a weld in thin walled (1.5mm) stainless steel tubing. The tubing is said to be fracturing from the inside to the outside in the heat affected zone.

I look for to your Ideas and to Rolf telling me where the old post are. I can only plead tired eyes?


Kindest Regards
Michael Trinidad


 
03:05 Oct-06-1998

Rolf D.

Director, Editor, Publisher, Internet, PHP MySQL
NDT.net,
Germany,
Joined Nov 1998
602
Re: Thin walled (1.5mm) Welded Stainless Tubing g
process using ultrasonics. How small of a crack can be detected using this method and where can I get a list of North American
vendors.


Follow Ups:
http://www.ndt.net/wshop/forum/messages/271.htm
Re: Crack detection in thin wall exhaust tubing Tom Nelligan 18:01:35 7/02/98 (0)



 
03:48 Oct-06-1998

Ed Ginzel

R & D, -
Materials Research Institute,
Canada,
Joined Nov 1998
1208
Re: Thin walled (1.5mm) Welded Stainless Tubing st in the metal will make it difficult to determine geometry from flaw.

Do you have access from the ID or OD?
I have seen good techniques using a small diameter element in a rotating head used from the ID. In that case the signals were displayed as a B-scan (stacked A-scans).
Data was obtained from a helical scan as the probe advanced along the tube. The probe was configured to provide a nominal 45 degree shear in the metal and interpretation
was by observing the Bscans for signals arriving earlier than the ID. But this was for smooth tubes in a tube sheet.
If there is a girthweld in the tube the probability that you get past the root with such a technique is low.
To overcome this you probably need to position your probe at a fixed distance VERY precisely with respect to the cap or root geometry.

If access is from the OD only then the bigger problem is more mechanical. The ID technique assumed a head of water was available for coupling.
If you must work from the OD coupling is a significant problem. A stuffing box filled with water and rotating the tube would be ideal but your tube is probably in situ.
Contact testing will be virtually useless due to the entry noise. A customised probe fixture with a good water seal would be nice.
In contact testing, by the time the noise level is down the beam will have traversed far enough that several modes are present making interpretation DIFFICULT.
If you can rotate the probe arond the OD at a known fixed distance and display a Bscan you might be able to separate defect from flaw signals by pattern.

Have you considered options other than UT?
Eddy Current (depends on the stainless quality), Fluorescent dye and boroscope, thermography to assess local heat losses.

Ed





 
07:55 Oct-07-1998

Bill Chestnut

NDT Inspector
self employed,
United Kingdom,
Joined Nov 1998
3
Re: Thin walled (1.5mm) Welded Stainless Tubing : Some time ago the question was posted concerning the inspection of welds in thin walled tubing. I cannot recall if the tubing was stainless steel or not and cannot find it here in the archive for perusal. Therefore what would be best suited for inspecting a weld in thin walled (1.5mm) stainless steel tubing. The tubing is said to be fracturing from the inside to the outside in the heat affected zone.

: I look for to your Ideas and to Rolf telling me where the old post are. I can only plead tired eyes?

:
: Kindest Regards
: Michael Trinidad
-----------------

I was involved in the testing of stainless steel tues of this geometry and material at the Sellafield reprocessing plant about 7 years ago, the technique we used was to use an off the shelf 4MHZ 45 Deg probe(10mm OD single crystal) set the sensitivity to FSH off a 0.5mm spark eroded notch set in a sample of the same pipe, generally indications over 60% should be investigated, we found this method excellent for detecting LORF & LOP but I'm sure it would detect cracks equally as well, note that for the beam of the sound top reach the weld root will take 2.5 skips or 5 traverses for a wall thickness of 1.8mm.

I hope this information is help to you,

Bill Chestnut



 
02:25 Dec-20-1998
Correct-Tech Inc
Re: Thin walled (1.5mm) Welded Stainless Tubing
: Some time ago the question was posted concerning the inspection of welds in thin walled tubing. I cannot recall if the tubing was stainless steel or not and cannot find it here in the archive for perusal. Therefore what would be best suited for inspecting a weld in thin walled (1.5mm) stainless steel tubing. The tubing is said to be fracturing from the inside to the outside in the heat affected zone.

: I look for to your Ideas and to Rolf telling me where the old post are. I can only plead tired eyes?

:
: Kindest Regards
: Michael Trinidad




 
02:29 Dec-20-1998
Correct-Tech Inc
Re: Thin walled (1.5mm) Welded Stainless Tubing I am looking for 1/4" od x 2" stainless capillary's to pot a thermocouple into for water temperature sensing. Do you have this or can you help me find them?

Regards Ted Williams



 
02:30 Dec-20-1998
Correct-Tech Inc
Re: Thin walled (1.5mm) Welded Stainless Tubing I am looking for 1/4" od x 2" stainless capillary's to pot a thermocouple into for water temperature sensing. Do you have this or can you help me find them?

Regards Ted Williams



 
02:33 Oct-21-1999
Julia Ziebarth
Re: Thin walled (1.5mm) Welded Stainless Tubing Laser Beam Technology opens in Hayward Ca, we offer non conventional laser processing of materials, laser welding ( thin cross section )of most metals, Laser cutting most metals and oxides, Laser drilling (small holes) and large, wafer marking and Laser engraving.
Prototype design to production.
Look for us on the NTMA web.
Contact: Eric Ziebarth for more details.
P-510 887 1603
F-510 887 1608
e-mail-laserbeam@libertybay.com


 
11:11 Aug-14-2015

mamta mishra

Student,
NDT using ultrasonics,
India,
Joined Aug 2015
12
Re: Thin walled (1.5mm) Welded Stainless Tubing In Reply to Bill Chestnut at 07:55 Oct-07-1998 .

what is this traverse and skip method i mean 2.5skip or 5 traverse. how can we implement it by using only A scan monitor.

kindly help me out.

 


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