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20:12 Dec-05-2009
Syed Asif Ali
What is the Minimum thickness limit for manual UT

Respected Experts
Questions which are asked from me many time about the Ultrasonic Testing is that. What is the Minimum thickness limit for manual UT and what code and standards guide about it?
My answer is always “There is no minimum limit for Ultrasonic Testing. It is depending on your equipment, experience and the inspection contact. For minimum thickness use 70 ° probe if available use twin crystal (TR). Scan in 3rd to 4th Leg. Use the option of zoom. If the weld capping is removed it is better. If the material is ferromagnetic then test the weld by Magnetic Particle Testing before the Ultrasonic Testing.
But if the capping is exist and it is not uniform you will face some echo form edges (undercut etc) the echo form top surface can be checked but the echo from bottom surface (if not accessible) are difficult to evaluate .
The best paretic for this, manufacture a block of artificial Defect and demonstrate your skill on it I think every one will be accept it
Does standard address this issue?
Thanks

 
08:13 Dec-06-2009

S.V.Swamy

Engineering, - Material Testing Inspection & Quality Control
Retired from Nuclear Fuel Complex ,
India,
Joined Feb 2001
783
Re: What is the Minimum thickness limit for manual UT In Reply to Syed Asif Ali at 20:12 Dec-05-2009 (Opening).

Dear Syed,

There are specific standards for specific products that address the procedures to be used for determining the thickness. For example, we (in my earlier organisation) were inspecting routinely zircaloy fuel tubes of thickness 16 mils (approx. 0.4 mm) using automated immersion testing systems. We were using only 10 MHz frequency and so with the right electronics and probes, we can if needed go even lower. On the other hand, we use Beta Back scatter technique for determining the thickness of graphite coating on the inside of the same tube of the order of about 4 to 8 microns.

Similarly Eddy current test is used for some coating thickness measurements. In all cases, it is of course necessary to prove the technique, the equipment etc. through proper calibration.

Best regards

Swamy

 
08:14 Oct-20-2011

vijay

India,
Joined Oct 2011
1
Re: What is the Minimum thickness limit for manual UT In Reply to S.V.Swamy at 08:13 Dec-06-2009 .

Dear sir.

I am as a ut technician, i was since work in qatar, cna you help me, i have on e doubt ,ultrasonic testing for minimum thickness in normal probe 0 degree ,tr probe and
angle probe ,how much minimum thickness,

another one doubt ,we cna use in reference block iow block, there is five different hole one by one continuous ,after three hole middle and corner ,

iam which one catch in fist 80 percent, can you tell me sir

 
00:03 Oct-21-2011

Csaba Hollo

, Senior Technician
Acuren Group Inc.,
Canada,
Joined Feb 2010
301
Re: What is the Minimum thickness limit for manual UT In Reply to Syed Asif Ali at 20:12 Dec-05-2009 (Opening).

Measurement of minimum thickness with any accuracy would be dependent on the ringdown from the reflected echo. It would be simple to use a point on the leading edge, say 80% FSH of the first backwall, and measure the time of flight to the second backwall echo at the same point of the leading edge. If your instrument range goes down that far, broad controls to modify signal shape, and you have a high frequency broadband txdcr that gives you sharp signal ramps, fractions of a millimeter are possible.

With respect to manual weld inspection/angle beam in thin materials, there comes a point where the sound beam totally saturates the area under test, and very little discrimination can be made with respect to characterization of a flaw within the area of interest, and even detection in some cases.

 
14:15 Oct-22-2011

massimo carminati

Consultant, AUT specialist
IMG Ultrasuoni Srl,
Italy,
Joined Apr 2007
691
Re: What is the Minimum thickness limit for manual UT In Reply to Syed Asif Ali at 20:12 Dec-05-2009 (Opening).

If I have understood the point, you are asking about smaw welds on pipes, am I correct?
If it is so, you should first relate to applicaple standards. In the "EN environment", the applicable codes for Manual UT range is from 8mm thickness up. This makes a lot of sense to me when UT has to be performed on SMAW welds. In different situations, you can clearly lower this limit, but you need to demonstrate good separation from geometrical reflectors and real defects.

 
04:50 Oct-23-2011
WOWA
Re: What is the Minimum thickness limit for manual UT In Reply to S.V.Swamy at 08:13 Dec-06-2009 .

S.V Swammy we talk about manual UT la.. ASME give 8mm for minimum for Manual UT and AWS not yet specified about that.. So what you need is,if you want scan 6mm u need demonstrated with procudere approve by NDT L3.. You can get L3 a lot in India.. They can do anything.. Just my 20cent.. Peace!!

 
15:36 Oct-24-2011

S V Swamy

Engineering, - Material Testing Inspection & Quality Control
Retired from Nuclear Fuel Complex ,
India,
Joined Feb 2001
783
Re: What is the Minimum thickness limit for manual UT In Reply to WOWA at 04:50 Oct-23-2011 .

All our procedures were written down and approved by all the concerned bodies in the Department of Atomic Energy. We had all the approvals. My answer was in that direction only.

Regards

Swamy

 
21:01 Oct-24-2011

massimo carminati

Consultant, AUT specialist
IMG Ultrasuoni Srl,
Italy,
Joined Apr 2007
691
Re: What is the Minimum thickness limit for manual UT In Reply to S V Swamy at 15:36 Oct-24-2011 .

Mr. Swamy,

I can understand your point, but 0,4 mm thickness of zircaloy fuel tubes is a completely different application and, probably, much easier than any a 6 mm SMAW weld with:
approximate gap
approximate preparation
"good" hi-lows
excess of penetration
and finally 15 mm cap width.

I contributed in the development of IBW AUT systems, down to 1,6 mm thickness, but this approach cannot be used un SMAW welds, therefore, I did not mention it as an example.

 
16:51 Oct-25-2011

S V Swamy

Engineering, - Material Testing Inspection & Quality Control
Retired from Nuclear Fuel Complex ,
India,
Joined Feb 2001
783
Re: What is the Minimum thickness limit for manual UT In Reply to massimo carminati at 21:01 Oct-24-2011 .

OK, I understand your point of view but even the welds that you are referring to need to be inspected and the procedure has to address the limitations of the testing. If needed, the welds need to be tested using an array of NDT methods and techniques (PT / MT, UT, RT etc.). If the codes don't give a standard procedure, the same has to be developed.

I have been involved in such work too!

Regards

Swamy

 
21:31 Oct-25-2011

massimo carminati

Consultant, AUT specialist
IMG Ultrasuoni Srl,
Italy,
Joined Apr 2007
691
Re: What is the Minimum thickness limit for manual UT In Reply to S V Swamy at 16:51 Oct-25-2011 .

"Need to be tested", correct.
Combinations of NDTs, correct.
Let's not change the focus, anyway.
A laser beam weld cannot be brought as an example to state that a similar thickness of SMAW weld can be inspected with UT, or to demonstrate that UT can do everything!

Best method for 6 mm on site, as welded SMAW weld is RT, do everybody agree?
In my opinion we can start comparing RT and UT efficiency starting from 12 mm.

Comments are appreciated

 
23:19 Oct-25-2011
WOWA
Re: What is the Minimum thickness limit for manual UT In Reply to massimo carminati at 21:31 Oct-25-2011 .

I'm agree with you massimo.. we can do manual UT on 6mm SMAW joint but not practical because the efficiency and accuracy less than RT.

But for doing RT a lot inhouse procedure to be follow,example safety. Take time to make joint setting and etc.

But if MUT you can done only in minutes. Couplant scan reported!! Owh LOSWF not detected. (UT operator not good and buy a NDT cert. with money)

Peace!!

 
22:35 Oct-27-2011

Lalit Mohan kothari

Consultant, -
On ..IOCL and BARC(Bhabha Atomic Research Centre).etc,
India,
Joined Jan 2003
128
Re: What is the Minimum thickness limit for manual UT In Reply to WOWA at 23:19 Oct-25-2011 .

Wowa,
You can inspect less than 6 mm by 4 MHZ and it is general everywhere in SAW pipe industry as pipe thickness range less than 6 MM is also acceptable and as notch depth point of view it is near about 3 mm and If FBH is there may be less than 3 mm for calibration and UFD detects it .
For RT and UT point of view RT cant detect planner defects while UT parallel to the ray /perpendicular defects and this is the one of main reason to do the both RT & UT and although so many limitation is also …. .
If you think theoretically then it is very very difficult to satisfy any body as near ZONE and DEAD Zone “s range is very high.
.
As accuracy point of view in SAW pipe everywhere Auto UT is also their if any doubt /indication is their pipe is forwarded for MUT but a lot of indication is their only pattern helps some extent……and UT is not that much reliable as RT …if ID and OD welding layer not properly overlap each other then it is more difficult to interpret the bunches of echo’s…..
So final decision is taken on the bases of RT is possible.
As pipe size is not that much varies any new comer can perform UT on plane surface ….Even UT operator is expert can do mistakes also….
Level # 3 is in all over the world and and above all Level # 3 not a authority ….standard body is everywhere and all the best Inspection Companies offices in INDIA and they are not coming here to collect the coins /cents
You might not be aware that president of World society of NDT is an INDIAN…

Thanks & Regard

 
05:58 Oct-28-2011

massimo carminati

Consultant, AUT specialist
IMG Ultrasuoni Srl,
Italy,
Joined Apr 2007
691
Re: What is the Minimum thickness limit for manual UT In Reply to Lalit Mohan kothari at 22:35 Oct-27-2011 .

SAW on less than 6 mm?
Notch depth 3 mm?
Pipe size is not that much varies?
And finally what is this "spot" for Indian level 3s?

Lalit, what's the weight of your contribution?

 
17:23 Oct-28-2011
gary whitworth
Re: What is the Minimum thickness limit for manual UT In Reply to Lalit Mohan kothari at 22:35 Oct-27-2011 .

Lalit,
You are confusing me.

 
18:43 Oct-28-2011

massimo carminati

Consultant, AUT specialist
IMG Ultrasuoni Srl,
Italy,
Joined Apr 2007
691
Re: What is the Minimum thickness limit for manual UT In Reply to gary whitworth at 17:23 Oct-28-2011 .

Sure, he is!
Hope this will terminate soon.

 
00:54 Oct-30-2011

Mario Talarico

NDT Inspector,
Italy,
Joined May 2010
382
Re: What is the Minimum thickness limit for manual UT In Reply to Syed Asif Ali at 20:12 Dec-05-2009 (Opening).

Syed,
to my knowledge, a weld of 9.5 mm mm can be checked regularly with standard probe 8x9, angle 70 °, half step for the root and whole step for outside cap. Of course I refer to a weld with no access to the back, geometries of misalignment and excess root penetration. The italian pipelines 'dorsal' lombard (hollander) is in this case.
With this technique, the thickness 7 mm is rather prohibitive (impossible to analyze the root: in certain pipelines 7mm welding has been scanned sided curve only, more thick).
The control of these joints is not an easy task, especially in pipelines where the most serious defects are at the bottom of the tube, with difficult access and presence of mud, water, etc., under our feet. As far as I could verify, for these welds, specific training on signals is necessary.
Logically, with same technique and probes dn ¼ "- index 6 mm-, or with a technique half step in the root and full step in outside cap, we can (why not?) to reduce this thickness of a few mm. We can not give abstract numbers because there is another important parameter to define: the width of cap outside. Once know these two parameters, to simulate the geometry in the root (misalignments and excess) together with notches to define the feasibility . Of course with criteria and reference block provided.

Wowa,
which ASME part are you referring to the limit of 8 mm thick? Did you want to refer to EN?

Greetings
Mario

 
07:53 Oct-30-2011
WOWA
Re: What is the Minimum thickness limit for manual UT In Reply to Mario Talarico at 00:54 Oct-30-2011 .

sorry bro,wrong info. not ASME not specify min. thick but AWS specify 8mm min.

 
08:09 Oct-30-2011

massimo carminati

Consultant, AUT specialist
IMG Ultrasuoni Srl,
Italy,
Joined Apr 2007
691
Re: What is the Minimum thickness limit for manual UT In Reply to Mario Talarico at 00:54 Oct-30-2011 .

Mario, thank you for your post; you brought back the topic focus.
Back to the original question, there must be a reason why EN establish that 8 mm is the limit for application. As a general advice, I would always use a profilometer + thickness measurement in order to determine hi-lows and estimate geometrical reflections. Another important point is the possible error of WCL position due to weld cap offset. In many casesthe weld cap is not centered on the WCL raising to errors of interpretation for geometrical indications or lack of penetration.

 
11:38 Oct-30-2011

Mario Talarico

NDT Inspector,
Italy,
Joined May 2010
382
Re: What is the Minimum thickness limit for manual UT In Reply to massimo carminati at 08:09 Oct-30-2011 .

Massimo,
profilometer question. I know and am friends with many full time for pipeline UT butt-weld operators (Genoa school). I'm talking about contracts for ultrasound examination before RX, and conflict - when necessary - with the reading of the film ( 8x9 standard probe, 12,8-11,9-9,5 thicknesses, calibration very high sensitivity with hole 1.5 +6 dB).
None of them, including me, have never used the profilometer for the estimation of geometric reflections. The variation of misalignment on large diameters is continuous, but gradual and almost imperceptible. It is a persistent phenomenon, although variable on the circumference. Nobody wants to spend her life with the meter in the hands! The measure can only be a verification tool: thus a end point of the analysis, not to start.
I see no solution outside of much practice: specific field training of UT operator for dynamic analysis and specific examination as filter before putting it into production. I understand the difficolt, but this is what has always been done in situations known to me.
WCL question. I agree with you in case of piping environment and thick more higher. But that is another subject.
The deviations of WCL on small thicknesses are minimal. To my knowledge does not compromise the analysis of the root, not even we can claim for excuse in case of failure.
As for ASME code I have not found references to minimum thickness.
Regards
Mario

 
16:42 Oct-30-2011

massimo carminati

Consultant, AUT specialist
IMG Ultrasuoni Srl,
Italy,
Joined Apr 2007
691
Re: What is the Minimum thickness limit for manual UT In Reply to Mario Talarico at 11:38 Oct-30-2011 .

I agree that using the profile and thickness gauge is somehow time consuming, but if you assume an echo >50% DAC is due to root signal and this is within the thickness, than you need to give "foundations" to your assumption. So, if this is geometric reflection and due to 2 mm misalignment, then you need to demostrate it, or, at least, to be sure of.
If you have tube-to fitting weld than it is even more important. Are you always that sure that thicknesses are as per schedule requirements?

 
22:18 Nov-01-2011

Mario Talarico

NDT Inspector,
Italy,
Joined May 2010
382
Re: What is the Minimum thickness limit for manual UT In Reply to massimo carminati at 16:42 Oct-30-2011 .

Massimo,
internal geometrical configuration of pipelines butt-weld corresponds with that exsternal, so it's predictable. This may explain the absence of profilometer for signals analisis in this environment.
“Tube-fitting to weld”, what pain! This subject pushes us too off topic, so only a few words. I always am embarrassed when I place an angle beam probe on a curve of thickened weld-piping, normaly irregularly and unpredictable tapered and I think: " Here are the limits of your method: you are Mario, not SuperMario".
We close with a positive note, the piping curves are often regular in thinner thickness that are debating.
Greetings.
Mario

 
06:46 Apr-17-2012
sudhakar kumar
Re: What is the Minimum thickness limit for manual UT In Reply to massimo carminati at 21:31 Oct-25-2011 .

BUT Sir.is this possible to carry out all the inspection using RT at the site, means if the length is more than?

 
09:17 Apr-17-2012

Mohammed

R & D
South Korea,
Joined Oct 2010
27
Re: What is the Minimum thickness limit for manual UT In Reply to Mario Talarico at 11:38 Oct-30-2011 .

Dear all
Thanks for the good discussion..
I am sorry that I posted a similar thread before I come through this post, my question was why AWS sets thickness limit of 8mm in the UT of weld? is it due to skip distance and attenuation if you use 3rd or 4th legs? is it due to the sound beam behavior in thin materials? is it due to some geometrical considerations?

I am not asking is it possible to inspect less than 8mm or not, because I understand that everybody has his own experience/views/scope/objective,

My question is about the REASON which made these standard making bodies to set the limit.

Regards

 
16:56 Apr-18-2012

Mario Talarico

NDT Inspector,
Italy,
Joined May 2010
382
Re: What is the Minimum thickness limit for manual UT In Reply to Mohammed at 09:17 Apr-17-2012 .

Mohammed,
often when we speak about limits control we tend to think in abstract way ( just because we tend to exceed these limits ). So, in our case, we think that just need to respect the near-field limits using a suitable angled single beam probe (DN5 standard probe, 2MHz, N = 3.85) or angled double beam probe.... and so the game would be done! Unfortunately, in the real world, not is enough to pull-on a signal and differentiate it from noise conditions! The signals should be evaluated with the requirements of a standard.

I'm not familiar with AWS, however EN also imposes a constraint of 8 mm. Abstracting from engineering criteria unknown to me, I believe that NDTregulators, as a precaution, do not want to encode too many subcases (furthermore someone can always escape! ). For example, EN imposes a constraint of a certain difference in dB for defect classification as a planar, if required, by comparing two angles shear waves (9 dB) or comparing an angle shear waves and the other longitudinal waves (15 dB, but it is unclear if this applies also to the comparison between 0 ° probe and angled shear waves probe, although this technique of differentiation is commonly used ). Using paths between 1 and 1.5 skip, as it is often practiced in thin layers, is quite difficult to meet this requirement because is very difficult to ensure that the signals come from the same reflector and be sure also that the geometry does not affect differently the views in comparison, subtracting or changing part of the beam. We would therefore have a series of case studies to define! We could opt for smoothing the external cap and go for E-R double beam angled probes. However, we should establish some limits and put this case in the standard, that jet provides this only after agreement between the parties….. In short, finally, someone, or more than one, wisely, considering also the opportunity to avoid the imposition of a mockup for the cases as weld ( other constraints and cases to be defined!) , has evaluated the general scaffold of the standard and has stopped at 8 mm: approximately root scanning limit with standard probes. And this latter circumstance seems to me the 'mother of all wars', because someone considered that for many years the UT world has well turned into most applications with 8x9 dimensions probes.

Other rules do not define thickness limits. Is responsibility of the parties concerned to assess the full compliance: sometimes just a simple on/off evaluation or some level amplitude evaluation; sometimes all becomes complicated depending of signal evaluation requirements. Responsibility us understand what we are handling.

Each of us can feel more or less comfortable in first or second situation. For my part, in production (of checks) should be certain rules and it is important that, in the first as the second way, come to the parties concerned. Better if few and respected rather than many and mostly disregarded. But , as we know, even for this latter consideration, we are in a real world!
Greetings
Mario

 
19:19 Apr-18-2012

Ian S

NDT Inspector, Auditer / Cross Checker
STS { Stork Technical Services } Australia,
Netherlands,
Joined Aug 2011
59
Re: What is the Minimum thickness limit for manual UT In Reply to Mario Talarico at 22:18 Nov-01-2011 .

Hi Guys,
I regulary examine 5/6mm tubular TKY's on container cranes at the ECT in Rotterdam using a 4mhz 3.5 x 3.5 mm twin crystal 70 dg probe, works beautifully, standard time base calibration of 0 - 50 then on to the V1 1.5 mm sdh for some fine tuning if necessary..

 
19:24 Apr-18-2012

IanS

NDT Inspector, Auditer / Cross Checker
STS { Stork Technical Services } Australia,
Netherlands,
Joined Aug 2011
59
Re: What is the Minimum thickness limit for manual UT In Reply to Mario Talarico at 16:56 Apr-18-2012 .

My apologies gentleman the V1 should read 20mm V2 1.5 mm sdh

 
14:44 Apr-19-2012

Mario Talarico

NDT Inspector,
Italy,
Joined May 2010
382
Re: What is the Minimum thickness limit for manual UT In Reply to IanS at 19:24 Apr-18-2012 .

Ian,
thanks for sharing your experience.
I also use a hole sdh from 1.5 for the feasibility, together with surfacing internal and external notch, located on the side of the weld, as start and end points of geometrycal differentiation (sdh then as the midpoint). The sensitivity setting is done with standard reflectors, which are not always those of feasibility.
3.5 x 3.5 mm crystal twin: is very nice! Normally are available twin crystal 4x10 or similar dimensions.
Where did you get these probes? Special probes are manufactured specifically for you? What fire in steel have? What extent the index? You can also provide some information about the technique you use?
greetings
mario

 
22:22 Apr-19-2012

andrew cunningham

NDT Inspector
Canada,
Joined Jun 2008
238
Re: What is the Minimum thickness limit for manual UT In Reply to Syed Asif Ali at 20:12 Dec-05-2009 (Opening).

If you use a 80 or 90 degree probes, it will open a new window of testing thin materials

 
03:33 Apr-20-2012

Mohammed

R & D
South Korea,
Joined Oct 2010
27
Re: What is the Minimum thickness limit for manual UT In Reply to Mario Talarico at 16:56 Apr-18-2012 .

Thanks Mr. Talarico
I really appreciate your informative and detailed reply;
I completely agree that we should respect the rules set by the standards, I am just looking for understanding how these experts in the standard-making bodies think,
I am thinking if we understand the facts those were considered when they built the standard would help us to more respect it, and may help and motivate us to think about development especially there is a lot of water passed under the NDT bridge since that standard was set.
Regards

 
06:18 Apr-20-2012

massimo carminati

Consultant, AUT specialist
IMG Ultrasuoni Srl,
Italy,
Joined Apr 2007
691
Re: What is the Minimum thickness limit for manual UT In Reply to Mohammed at 03:33 Apr-20-2012 .

Something is moving in the codes about this thin welds, applying phased array.

 
07:03 Apr-20-2012

Mohammed

R & D
South Korea,
Joined Oct 2010
27
Re: What is the Minimum thickness limit for manual UT In Reply to massimo carminati at 06:18 Apr-20-2012 .

This is an important news Massimo..
Any idea about how they gonna address it?

 
10:11 Apr-20-2012

Tyler

Consultant, Pipeline
NDT Consulting,
Germany,
Joined Feb 2009
5
Re: What is the Minimum thickness limit for manual UT In Reply to Syed Asif Ali at 20:12 Dec-05-2009 (Opening).

Dear Syed,

I think the 8mm is based on the following considerations:
30° bevel => 60° Probe
8x9mm 4MHz standard probe with 13mm exit point
Near field ca. 33 mm
Root defects sound path at ca. 17mm (already well into the near field)
In 8mm depth the projected surface distance is ca. 15mm (2mm in front of our probe)
The weld cap with a hand weld of 8mm is ca. 12mm (can be much larger) so our probe is at least 6mm from the weld plus 13mm exit point = 19mm. This means that we are 4mm from the weld centre in the root. So a 60° probe is not giving us full coverage of the weld unless we test the root in the skip and in the third skip our bundle is already nearly 8mm high so separating geometry from defects becomes very difficult.
70° is not optimal for the bevel but here we are at least in the root at ca. 29mm (end of the near field). Our bundle -6dB drop is already about 6mm high at this distance and we even can have geometric reflection from the root and the cap on the screen at the same time.
Going thinner than 8mm with standard probes and methods is not a good idea.
Thinner material may be tested with UT but you need to put a little more thought into the methods as stated in the original post. This is the reason, in my opinion that standard hand UT on manual welding should stop at about 8mm.

Tyler

 
10:43 May-04-2012
thananon
Re: What is the Minimum thickness limit for manual UT In Reply to Tyler at 10:11 Apr-20-2012 .

Dear Sir
I would like to know what are your application if thickness measurement that may be start from 0.8 mm becuase depend on angle roof of the transducer and frequency.
For welding start at 3 mm up. Some spec may tell you min thickness is 8 mm up becuase if you you check lower than 8 mm that should be occur the transverse wave change the mode become to plate wave but you can change to high frequency to avoid the wave type have change.

 
15:41 May-04-2012
john
Re: What is the Minimum thickness limit for manual UT In Reply to Syed Asif Ali at 20:12 Dec-05-2009 (Opening).

MY answer would be no limit on min thickness depending on the type of UT that you are try to do.
If shear-wave there would be practical limits as to the min thickness and what you were trying to accomplish. Whether or not it is plate or weld, go / no go criteria, etc. IF 0-deg, there are pen probes that will measure accurately with great resolution down to .010". there is also surface wave inspection to consider.

Regards

 
17:37 May-04-2012

andrew cunningham

NDT Inspector
Canada,
Joined Jun 2008
238
Re: What is the Minimum thickness limit for manual UT In Reply to Syed Asif Ali at 20:12 Dec-05-2009 (Opening).

I totally agree with John.
If you have some reference pieces made with some known maximum allowable and minimum rejectable defects put in. Then practice on them and or to test others on. Why push the envelope.
But remember.
Put the thickness on the report as a limitation.

Andrew c

 
04:05 May-06-2012

Mario Talarico

NDT Inspector,
Italy,
Joined May 2010
382
Re: What is the Minimum thickness limit for manual UT In Reply to Syed Asif Ali at 20:12 Dec-05-2009 (Opening).

Syed,
I agree with the last post by John and Andrew.
My previous boss (maybe talk about a century ago!) was using surface waves to understand the origin of the cracks on cans of fizzy drink of a known manufacturer in the forming phase (or plugs: I do not remember well). Surface waves is a good competitor of eddy current applications. I've never found a trace in the routine of UT standards prescribed for a wider range of thickness for wide use,
It is true that sometimes the limits are normative: EN1712 (EN 11666) limits the checks welds to 8mm; EN 10160 limits to 6 mm the plates control; ISO 12094 go down to 4 mm. Inside the limits we are sure: someone did the work for us. This is what prefers who makes applications!
It is true that sometimes we need to understand the limitations during the starting-up of application. Consider ASTM B775, entitled "Standard Specification for General Requirements for Nickel and Nickel Alloy Welded Pipe". This is a classic on/off control. The standard reflectors for UT are notches 12% of the thickness or 0.1 mm (the larger of the two). Are not specified limits of thickness. Reference testing is E213 (pulsed ultrasonic angle beam, contact or immersion). The same standard is used for eddy current applications!!
Message received: know when you're over with a method, then seek another method and use it according to application demand (e.g. with a transverse notch, hardly an immersion method has the eddy current performance ..... at least in speed).
More difficult. ASME V Art. 4: there are no explicit thickness limits for weld control. If we look at test-block figure for curved 'components' welds control, Fig T434.1.7.2 Asme V art.4, a test-block diameter 26 mm can be built and then a control of such welding can legitimately be requested and performed. Abstracting from the problems of transmission and reflection due to the curvature, and the inability to include SDH radial in the quantity and size requirements, we must objectively consider that for this diameter schedule tables provide values of thicknesses from...... 1.65 to 7.9 mm. Furthermore, in this case, on/off methods are not allowed: the defects must be differentiated and different acceptability criteria must be applied depending on the type of defect. It 's an open and difficult challenge, incredibly, dated very back in the time in ASME.
Application demand!
And do not shoot yourself in the foot!
Greeting
Mario

 
06:18 Sep-17-2012
Navish
Re: What is the Minimum thickness limit for manual UT In Reply to Mario Talarico at 04:05 May-06-2012 .

May I add one more question to the thread.... I've the situation where I got the joints which are 3.5" dia and 6.5mm thick and they are TKY configurations.

As mentioned in AWS clause 6.27.1 (1) conventional techniques are generally limited to 12” dia and 12mm thickness and 30degree dihedral angle.

Special technique for smaller sides may be used provided they qualified as described herein, using the smaller size of application…and later detail mentioned in (2) to (14).

Do any had done this before as mentioned by Mr. Ian from Rotterdam but he didn’t mentioned whether done in tubular or nontubular joints and if had done in tubular then up to what diameter is gone.

Please advice me for my question, or anybody have the UT procedure.

Appreciated your help in this regard

Thanks
Navish M

 
20:41 Sep-17-2012

Oliviero

NDT Inspector,
Quality Control srl,
Italy,
Joined Oct 2008
414
Re: What is the Minimum thickness limit for manual UT In Reply to Navish at 06:18 Sep-17-2012 .

A Moke-up could help you to find the right search unit, and to understand which type of indication could come back from the production joints.
The mock-up could be produced with SDH or notch or both in representative location. After that the mock-up could be sent to the Probe manufacturer to find the better solution and produce the search unit with wedge coupled with the OD.

 
02:54 Sep-19-2012

Mario Talarico

NDT Inspector,
Italy,
Joined May 2010
382
Re: What is the Minimum thickness limit for manual UT In Reply to Navish at 06:18 Sep-17-2012 .

Diagonal connection configurations complicate the control in the case of thin thickness: in the part with acute local dihedral angle, the external cap moves far the root access point, increasing the refraction angle required compared to other sectors of the joint. For this reason, the situation is more critical than the case of a butt-weld or T-joint.
For example, the root access during the control of set-on nozzles (90° nozzle to header T- joint), with thicknesses 6-6.5 mm, is complicated passing from the curved header part (large dihedral angle) to the straight header part (reduced dihedral angle). If I remember correctly, the feasibility is very made easier from access to the back. I find it hard to imagine a control by tilting the nozzle 30°-45 ° along the header.
The difficult cases can be seen in advance by graphical. For borderline or feasible cases, in presence of geometric complexity, a powerful tool -only apparently trivial- may be tracking directly on the piece (with a marker) the geometrical locus of root scanning position for a given angle, for example using reflections from holes having thickness direction located in the root or EDM notches in the root, if you have enough space. This provides simultaneously the feasibility (if in the given conditions exists) and the training for execution, in order to move safely along the welding during scanning.
greetings
mario

 
14:38 Sep-24-2012
Muhammad Azhar
Re: What is the Minimum thickness limit for manual UT In Reply to Syed Asif Ali at 20:12 Dec-05-2009 (Opening).

Dear All,

I didnt find clear answer of this question:
can we do thickness measurement with angle beam probe? I believe we cant do thickness measuement with angle beam probe beacause we have to put thickness in UT machine before doing Shear wave UT.
plz help me with prove or any mathematical calculation ....

I hope to c ur replies plzzzzz

 
19:09 Sep-24-2012
John
Re: What is the Minimum thickness limit for manual UT In Reply to Muhammad Azhar at 14:38 Sep-24-2012 .

You should go back and read initial query . You are looking for an answer to a question that wasn't asked. This pertains to the material thickness range for shear wave inspection, not thickness testing.
(and with the proper set up, and exacting calibrations it is possible to thks test with s-wave. Sound path is sound path !!!

 
07:39 Dec-10-2012
Naeem Amjad
Re: What is the Minimum thickness limit for manual UT In Reply to Syed Asif Ali at 20:12 Dec-05-2009 (Opening).

Dear Sir,
We intend to carryout Ultra sonic test on a stainless steel casted plate having dimenssion 300mm X 470mm , aprrox. 2inch hallow inside and having top surface thickness from 7 to 12mm and bottom surface 7 to 12mm.we require upper surface to be ultra sonic tested half of the surface is flate and the rest is in shape of hallow air vents,we would like to now the proper method of ultra sonic test which could indicate us the flaws.

 
07:40 Aug-31-2013
Anil Mhaske
Re: What is the Minimum thickness limit for manual UT In Reply to Syed Asif Ali at 20:12 Dec-05-2009 (Opening).

UPto 3mm

 
20:07 Sep-06-2013

velmurugan

Student,
AuroTech Inspection Service,
India,
Joined Jun 2013
7
Re: What is the Minimum thickness limit for manual UT In Reply to Muhammad Azhar at 14:38 Sep-24-2012 .

you know often straight beam from tr probe will not find defects. Tr probe throws sonic beam at 90 deg but when it comes to angle beam probe its not same as Tr ,it throws sonic wave at different angles say 30 40 60 70 but not 90.
Working of angle probe is like how we pitching a ball to the batsman in a cricket and it wont stop once it reaches the destination it will bounce back the way it comes.we can find defect in weld area but not thickness.

Its all about angle of incidence and a angle of refraction so called Snell's law.

 
06:32 Nov-25-2013
Navish
Re: What is the Minimum thickness limit for manual UT In Reply to massimo carminati at 06:18 Apr-20-2012 .

AWS asked to use only the transducer frequency 2 and 2.5 MHz probe inclusive stated in para 6.22.7.1, do you guys really think to check the 8mm welds 2~2.5 mhz probe is okay???

Regards
Navish M

 
12:02 Mar-11-2014
Hisar
Re: What is the Minimum thickness limit for manual UT In Reply to S.V.Swamy at 08:13 Dec-06-2009 .

What is the minimum detection limit with UT ?
If the reduction ratio of a steel bar is greater than 22, can we skip UT ?

 
01:31 Mar-12-2014

S V Swamy

Engineering, - Material Testing Inspection & Quality Control
Retired from Nuclear Fuel Complex ,
India,
Joined Feb 2001
783
Re: What is the Minimum thickness limit for manual UT In Reply to Hisar at 12:02 Mar-11-2014 .

Dear Hisar,

There is no standard / text-book answer to your question regarding the thickness limit for UT. We can test plates as thin as say 0.4 mm or may be even less. It all depends on the need and the instrumentation available.

Regarding your second question, again, the need for testing arises from the end use. Since all my working experience is in department of atomic energy, I would obviously be somewhat biased in favor of testing, whatever may be the reduction ratio. In fact, we test zircaloy sheets and wires of thickness / diameter less than 1 mm, though the same have been produced from an ingot of 350 mm diameter!!! Similarly very small diameter stainless steel tubes are tested for use in Fast Reactor components. These tubes go through a reduction ratio much higher than what you would normally encounter.

We use a combination of NDT Methods (UT, ET, VT etc.) - so, it all depends on the end use and the specifications.

 
22:55 Mar-13-2014

Mario Talarico

NDT Inspector,
Italy,
Joined May 2010
382
Re: What is the Minimum thickness limit for manual UT In Reply to S V Swamy at 01:31 Mar-12-2014 .

Very true! Everything depends greatly on the procedure that we use, the defects that we want to discriminate against and what we're checking and many other pratical things.
Nothing prevents to pass a tube or sheet of a few mm in thickness under a contact or immersion probe and pull up a notch after some interior and exterior skip. It is not the same thing for a weld, perhaps with some geometry too and analysis requirements greater than a banal on-off.
An increase in the required sensitivity could be in conflict and frustrate a well established procedure, simply ..... if the surface conditions are not adequate.
greetings
Mario

 
10:37 Apr-01-2014
karthick
Re: What is the Minimum thickness limit for manual UT In Reply to S V Swamy at 01:31 Mar-12-2014 .

I need to know this sir please 5mm and below we can do ut, and any procedure mention these type of thickness.

 
11:16 Apr-01-2014

S V Swamy

Engineering, - Material Testing Inspection & Quality Control
Retired from Nuclear Fuel Complex ,
India,
Joined Feb 2001
783
Re: What is the Minimum thickness limit for manual UT In Reply to karthick at 10:37 Apr-01-2014 .

Dear Karthick,

The answer is yes, we can do. As for the procedure, it very much depends on what sort of a component is involved. If you share more details, we can help you.

 
13:01 Apr-01-2014
karthick
Re: What is the Minimum thickness limit for manual UT In Reply to S V Swamy at 11:16 Apr-01-2014 .

Thanks for reply sir. more details means?? do you need which procedure or else .
And I m not find any procedure or standards to do 5mm plate. In case I did that mean I need reference standards sir. that's my question.

 
08:26 Apr-02-2014
Munze
Re: What is the Minimum thickness limit for manual UT In Reply to S V Swamy at 11:16 Apr-01-2014 .

Dear all,
I really appreciate everyone's involvement in this thread and making it that informative and useful.

My case is quite similar to this one.
We are having a chemical milling tank (4500*1800*2500) at our facility. The tank is composed of three layers. (tank outermost contact surface is SS 2.0mm, middle layer MS 3.5mm, inner most protective layer is plastic material). Chemical comes in contact with the SS layer and with the passage of time it has been established that the tank is having some defects causing leakage. In order to inspect this tank, I'm curious which ndt technique would be used. Keeping in view that only outermost surface is accesible i.e SS surface.

regards,
munze

 
09:58 Apr-02-2014

S V Swamy

Engineering, - Material Testing Inspection & Quality Control
Retired from Nuclear Fuel Complex ,
India,
Joined Feb 2001
783
Re: What is the Minimum thickness limit for manual UT In Reply to karthick at 13:01 Apr-01-2014 .

Dear Karthik,

The actual procedure for UT of any product depends on its end use and the specifications and standards applicable. When I mentioned more details, I was referring to the end use, applicable specifications and standards etc. - feel free to write to me directly at svswamy@gmail.com

Regards

Swamy

 
10:02 Apr-02-2014

S V Swamy

Engineering, - Material Testing Inspection & Quality Control
Retired from Nuclear Fuel Complex ,
India,
Joined Feb 2001
783
Re: What is the Minimum thickness limit for manual UT In Reply to Munze at 08:26 Apr-02-2014 .

Dear Munze,

I am wondering whether the order of the materials is reversed...you say the chemical comes into contact with the outermost ss layer, but then I am wondering what comes into contact with the plastic layer. Leakage indicates failure of the barrier in any case. Local exploration will be needed to ascertain the extent of damage.

If you share more details, we can discuss it more meaningfully...

Regards

Swamy

 
20:57 Apr-02-2014

Jorge Santin

NDT Inspector, consultant
Pró END Consultoria Ltda,
Brazil,
Joined May 2011
8
Re: What is the Minimum thickness limit for manual UT In Reply to Syed Asif Ali at 20:12 Dec-05-2009 (Opening).

We have tested and qualified manual UT procedures from 4,8 mm (3/16") and up. With 4,8 mm we have a good access to root inspection. The minimum nominal diameter we tested with good result is 2". We used the miniature probes (8x9mm). Under these limits it must be studied carrefully each application.

 
21:49 Apr-02-2014

Massimo

NDT Inspector,
Control s.r.l.,
Italy,
Joined Mar 2014
2
Re: What is the Minimum thickness limit for manual UT In Reply to Syed Asif Ali at 20:12 Dec-05-2009 (Opening).

Hello to all, for the en 17640 requires a minimum thickness of 8mm.
However, you may also check thickness below with appropriate probes with frequencies and crystal probe suitable for use, and any sample blocks.
Under the procedure then also recalls the minimum thickness to be controlled.
In my company we also check thickness up to 5mm (we use sample blocks with carving)

 
14:36 Apr-03-2014

Jorge Santin

NDT Inspector, consultant
Pró END Consultoria Ltda,
Brazil,
Joined May 2011
8
Re: What is the Minimum thickness limit for manual UT In Reply to Massimo at 21:49 Apr-02-2014 .

We normally use American codes. ASME B31.3 code for process piping dont' have thickness limitation except for high pressure piping weld inspetion. AWS D1.1 have the 8 mm limit, but have in the code alternative procedure for smaller thickness.

 
15:13 Apr-03-2014

G Madhesan

Consultant, Welding ýnspector/QAQC inspector
CHENNAI UNIVERSITY,
Turkey,
Joined Nov 2004
10
Re: What is the Minimum thickness limit for manual UT In Reply to Jorge Santin at 14:36 Apr-03-2014 .

Dear All,
As per my experience 8 mm and above can be done the Manual UT for weld scanning and 5 mm&above can be done for lamination by zero probes. Below 8 mm is difficult to scan and interpret the result considering the Near zone & Dead zones for related transducers frequencies.

 
19:00 Apr-03-2014

Jorge Santin

NDT Inspector, consultant
Pró END Consultoria Ltda,
Brazil,
Joined May 2011
8
Re: What is the Minimum thickness limit for manual UT In Reply to G Madhesan at 15:13 Apr-03-2014 .

Dear Mr.Madhesan
Please test again these small thickness. Check the coverage using USBeamtool. We use special root scanning, moving 70 degree probe paralel to weld. The result is much better that RT. The near field problem is compensate by DAC curve. The dead zone ends before root echoes.

 
13:06 Apr-06-2014
karthick
Re: What is the Minimum thickness limit for manual UT In Reply to S V Swamy at 10:02 Apr-02-2014 .

Sir,
i am using USM 35X ut machine and 70, 60, 45 angle probes & normal, T/R probes 10mm dia for all probes along this material can i do how lower thickness as weld joints and lamination plate or pipe.

 
14:51 Apr-06-2014
karthick
Re: What is the Minimum thickness limit for manual UT In Reply to S V Swamy at 10:02 Apr-02-2014 .

please describe the ASTM A435 standers Grid lines and acceptance criteria sir.
What are the reference block for this standard ASTM A435

 
19:11 Apr-06-2014

S V Swamy

Engineering, - Material Testing Inspection & Quality Control
Retired from Nuclear Fuel Complex ,
India,
Joined Feb 2001
783
Re: What is the Minimum thickness limit for manual UT In Reply to karthick at 13:06 Apr-06-2014 .

Dear Karthick,

I can't comment about machine specific queries, esp. since I retired from the job nearly 6 years ago and left the NDT field more than 10 years ago...

 
19:17 Apr-06-2014

S V Swamy

Engineering, - Material Testing Inspection & Quality Control
Retired from Nuclear Fuel Complex ,
India,
Joined Feb 2001
783
Re: What is the Minimum thickness limit for manual UT In Reply to karthick at 14:51 Apr-06-2014 .

Again, I can't comment since I have no access to the specification. However, it looks your query is regarding testing of plates for laminations. We used to test austenitic stainless steel plates of 6 mm, 12 mm and 16 mm thickness and zircaloy sheets of 1.2 mm thickness. While we used contact testing for the thicker stainless steel plates, we used immersion testing for the thin zircaloy sheets.

The grid lines and acceptance criteria are in my view described fairly clearly in the specification. If there is any specific doubt, we can discuss if you take the trouble of posting the relevant sections...

 
12:36 Apr-07-2014
Navish
Re: What is the Minimum thickness limit for manual UT In Reply to Navish at 06:32 Nov-25-2013 .

I asked below question on 06:18 Apr-20-2012 and havn't got any reply

AWS D1.1 recommend to use only the transducer frequency 2 and 2.5 MHz probe inclusive stated in para 6.22.7.1,
Do you expert, really think to check the 8mm ~ 15mm welds 2~2.5 mhz probe will effective?


 
07:17 Apr-09-2014

Vivek

India,
Joined Jan 2014
5
Re: What is the Minimum thickness limit for manual UT In Reply to Navish at 12:36 Apr-07-2014 .

Dear Navish

You ask this question two years before, still you did not get any ideas,,, try to get ideas yourself,,,
In AWS we can do 8mm weld scanning with 2MHZ probe,, we can find the discontinuity easily,, but we should know about near zone accordingly,,

 
08:30 Apr-09-2014
Navish
Re: What is the Minimum thickness limit for manual UT In Reply to Vivek at 07:17 Apr-09-2014 .

Dear Vivek,

I asked for expert veiw not the idea!!!

By the ways thanks for your reply... atleast you replied!! negative way!!!

 
09:30 Jun-22-2014
Karthik
Re: What is the Minimum thickness limit for manual UT In Reply to Navish at 08:30 Apr-09-2014 .

Any someone tell me which para of ASME defines the Wall thickness limitations for manual UT, i couldn't choose RT due to some design constrains on a 3" 80 Schedule pipe and People say UT is not efficient for thickness less than 8mm. I need to refer the exact para on the Code to justify the minimum 8mm thickness requirement to my client.

 
07:11 Jul-05-2014
Anuj Mavai
Re: What is the Minimum thickness limit for manual UT In Reply to S.V.Swamy at 08:13 Dec-06-2009 .

hello sir, i ask you that what is the minimum thickness ultrasound in ultrasonic flaw detector

 
12:51 Sep-05-2014
Prakash chakrabortty
Re: What is the Minimum thickness limit for manual UT In Reply to Muhammad Azhar at 14:38 Sep-24-2012 .

How to transfer in Angel probe reference from 3mm to 1.5mm?
I mean if I have a 3mm DAC so how to transfer this DAC to 1.5mm DAC?

 
13:43 Sep-05-2014

Mario Talarico

NDT Inspector,
Italy,
Joined May 2010
382
Re: What is the Minimum thickness limit for manual UT In Reply to Prakash chakrabortty at 12:51 Sep-05-2014 .

Prakash,
I do not have a precise memory in my head. Those who know me, on my reference blocks with standard 8x9 4Mhz or 17x17 2 Mhz ,indicative, about 4-6 dB. Bat ....indicative.
Reference block necessary for correct evaluation.
gretings
mario

 
15:45 Sep-05-2014

Jorge Santin

NDT Inspector, consultant
Pró END Consultoria Ltda,
Brazil,
Joined May 2011
8
Re: What is the Minimum thickness limit for manual UT In Reply to Prakash chakrabortty at 12:51 Sep-05-2014 .

The mathematic relation betwenn diameters of side driled hole is: db=10log D1/D2. So when you double de SDH diameter it chenges 3 dB in the gain. In relation to the distance the formule is: db=30log dist 1/dist 2, or you will have 9 dB when the distance is double for the same SDH diameter (far field).

 
04:41 Sep-06-2014

Ian S

NDT Inspector, Auditer / Cross Checker
STS { Stork Technical Services } Australia,
Netherlands,
Joined Aug 2011
59
Re: What is the Minimum thickness limit for manual UT In Reply to Prakash chakrabortty at 12:51 Sep-05-2014 .

Prakash, are you saying that you don't have access to suitable sensitivity block with 1.5 mm holes ?

 
09:09 Feb-20-2015
Thulani Khumalo
Re: What is the Minimum thickness limit for manual UT In Reply to S.V.Swamy at 08:13 Dec-06-2009 .

BS EN ISO 17640: States that you can test upto 8mm. Of cause there are some experiments that have been made up to 3mm but this is not stated in the procedures that i have ever read.

 
09:45 Feb-20-2015
prathabkumaran
Re: What is the Minimum thickness limit for manual UT In Reply to Anuj Mavai at 07:11 Jul-05-2014 .

above 10 mm thickness we prefer to UT. other wise we go to choose another method is best

 
14:09 Feb-20-2015
tarek
Re: What is the Minimum thickness limit for manual UT In Reply to Ian S at 04:41 Sep-06-2014 .

Hello

I think it's depend the probe being used in inspection, because the Minimum thickness limit for manual UT related to the near zone N=D*2 / 4 * length of the wave

 
06:47 Sep-16-2015
Gufran Haider
Re: What is the Minimum thickness limit for manual UT In Reply to massimo carminati at 18:43 Oct-28-2011 .

Minimum pipe thickness allow for ultrasonic testing, With reference Code.

 
11:35 Feb-29-2016
baccari tarek
Re: What is the Minimum thickness limit for manual UT In Reply to Gufran Haider at 06:47 Sep-16-2015 .

minimum diameter 50 mm
thickness shall be between 3 and 27 mm
reference ASME V-2013 ARTICLE 23 SE273 PAGE 500 1- SCOPE

 
20:51 Mar-07-2016

Jorge Perdigon

NDT Inspector, Teacher at Universidad Central de Venezuela - Factultad de Ingenieria
IEMAT, ca,
Venezuela,
Joined Jul 2009
10
Re: What is the Minimum thickness limit for manual UT In Reply to WOWA at 07:53 Oct-30-2011 .

By AWS D1.1 - 2015. "For thicknesses less than 5/16 in [8 mm] or greater than 8 in [200 mm], testing shall be performed in conformance with Annex Q. These procedures and standards shall be prohibited for testing tube-to-tube T-, Y-, or K-connections."

 
15:11 Mar-08-2016
Syed shah
Re: What is the Minimum thickness limit for manual UT In Reply to WOWA at 04:50 Oct-23-2011 .

In which section of ASME the thickness of 8mm and up is definded plz help me out

 
19:18 Mar-08-2016

Ed Ginzel

R & D, -
Materials Research Institute,
Canada,
Joined Nov 1998
1208
Re: What is the Minimum thickness limit for manual UT In Reply to Syed shah at 15:11 Mar-08-2016 .

Syed, this thread goes back a long way...to 2009. Many aspects of thickness were discussed over the past 6 years on this thread. In 2011 WOWA initially indicated that there was a reference in ASME to 8mm minimum but in his next posting he corrected that error and noted that this was an AWS value...not ASME. Unless you are referring to specific Code Cases, there are no limits in ASME, however, you will need to demonstrate capability if the AI decides to challenge your technique.

 
11:29 May-23-2016
muhammad fahad rana
Re: What is the Minimum thickness limit for manual UT In Reply to WOWA at 04:50 Oct-23-2011 .

Hey , i am Muhammad Fahad Rana , you said minimum Thickness limit for manual UT in ASME is 8mm , can you give me reference pls???

 
12:22 May-23-2016
International welding center
Re: What is the Minimum thickness limit for manual UT In Reply to muhammad fahad rana at 11:29 May-23-2016 .

thickness shall be between 3 and 27 mm
reference ASME V-2013 ARTICLE 23 SE273 PAGE 500 1- SCOPE

www.iwc-group.com.tn

 
13:30 May-23-2016

Ed Ginzel

R & D, -
Materials Research Institute,
Canada,
Joined Nov 1998
1208
Re: What is the Minimum thickness limit for manual UT In Reply to International welding center at 12:22 May-23-2016 .

Mr. International Welding Center, you have quoted a reference in Subsection B of ASME V. Please note the details of Subsection A Article 1 concerning the use of the ASTM standards in Subsection B. "These standards are nonmandatory unless specifically referenced in whole or in part in Subsection A..."
There is no mandatory minimum thickness quoted in the mandatory section of ASME V Articles 4. There is a single paragraph in Article 5, T-571.3, stating that tubular products shall be examined in accordance with SE-213 or SE-273. That same SE-273 document indicates an upper limit of 27mm thickness.
Therefore this reference is not a general acceptance of the range of thickness in ASME UT applications.

 
09:32 May-29-2016
SATHISH
Re: What is the Minimum thickness limit for manual UT In Reply to massimo carminati at 14:15 Oct-22-2011 .

Dear Sir,

We are doing now two pipelines One is 10" x 15.9mm WT, Another one 12" x 6mm.
My client is BP, their specification saying every RDX joints are should be MUT. I would like to know which wall thickness i can do weld scan (MUT) and can you tell any reference for minimum wall thickness.

 
18:02 May-29-2016

massimo carminati

Consultant, AUT specialist
IMG Ultrasuoni Srl,
Italy,
Joined Apr 2007
691
Re: What is the Minimum thickness limit for manual UT In Reply to SATHISH at 09:32 May-29-2016 .

The answer is in your question: Just follow BP's documents requirements; these documents normally comes first in the order of precedence.

 
04:34 May-31-2016

Anmol Birring

Consultant,
Birring NDE Center, Inc.,
USA,
Joined Aug 2011
622
Re: What is the Minimum thickness limit for manual UT In Reply to SATHISH at 09:32 May-29-2016 .

Following are the recommendations
15.9 mm thickness - use 5 MHz, 0.25 mm dia, 60 deg
6 mm thickness - use 5MHz, 0.25 mm, 70 deg

For both use low profile edges with small spacing between beam exit point and front of wedge.

Make scan plans to validate weld coverage
Calibrate on ID and OD notches

 
10:41 Jun-01-2016

massimo carminati

Consultant, AUT specialist
IMG Ultrasuoni Srl,
Italy,
Joined Apr 2007
691
Re: What is the Minimum thickness limit for manual UT In Reply to Anmol Birring at 04:34 May-31-2016 .

In addition to Anmol proper recommendations, I would suggest to use Dual shear waves probes high angle high frequency for lower thickness.

 
15:49 Mar-14-2017
sajid anwar
Re: What is the Minimum thickness limit for manual UT In Reply to Syed Asif Ali at 20:12 Dec-05-2009 (Opening).

Dear
i want to know how much minimum diameter accepted for manual UT.
or can i use 5mm diameter probe for 1 inch diameter tube or pipe?

 
17:29 Mar-14-2017

Ed Ginzel

R & D, -
Materials Research Institute,
Canada,
Joined Nov 1998
1208
Re: What is the Minimum thickness limit for manual UT In Reply to sajid anwar at 15:49 Mar-14-2017 .

Sajid, invariably manual UT is regulated by some code, standard or specification.
It might help to know what code or standard you are working to?

 
20:16 Mar-14-2017
Sajid Anwar
Re: What is the Minimum thickness limit for manual UT In Reply to Ed Ginzel at 17:29 Mar-14-2017 .

ASME B31.3 related to processing plant.
Can i use 5mm diameter dual probe to do corrosion mapping in 1 inch Diameter piping?
(From Manual UT Flaw detector)

 
09:04 Jul-12-2017

DEEPAK

, Mathew Associates QC Inspector as a NDT Co-ordinator
Mathew Associates ,
India,
Joined Mar 2012
1
Re: What is the Minimum thickness limit for manual UT In Reply to WOWA at 04:50 Oct-23-2011 .

CAN U GIVE ME IN DETAIL OF ASME WHERE IS LOCATED THAT POINT IN WHICH CODE & SEC

 
04:05 May-01-2018

kishore kumar

Right NDT,
India,
Joined May 2018
1
Re: What is the Minimum thickness limit for manual UT In Reply to S V Swamy at 19:17 Apr-06-2014 .

Dear Swamy,

I am a technician just completed my classes on UT.
My institute conducted a mock interview yesterday but I couldn't even answer them properly and felt ashamed of myself after that.
I want to improve myself for next time,can you please suggest me with the interview questions mostly asked for technician as well as NDT engineer.

Note* Massimo and Mario if possible I need you guys help even.

 
07:02 May-01-2018

Rakesh Parmar

NDT Inspector,
India,
Joined Dec 2014
58
Re: What is the Minimum thickness limit for manual UT In Reply to kishore kumar at 04:05 May-01-2018 .

Dear ,
U can find on google ,
easy available on net,

thanks

 
10:23 Sep-17-2018
Sivakumar
Re: What is the Minimum thickness limit for manual UT In Reply to Rakesh Parmar at 07:02 May-01-2018 .

All international (AWS & BS EN) standards are recommending of minimum thickness range is 8 mm and above of butt weld , But still Indian standard recommends for 6 mm and above.

 
00:20 Sep-18-2018

Sri Krishna

Sembmarine,
Singapore,
Joined Sep 2018
3
Re: What is the Minimum thickness limit for manual UT In Reply to Sivakumar at 10:23 Sep-17-2018 .

Mr. Siva,

First leave about code. Even if you don’t have code also you can perform UT. According to your requirement you can make demonstration and proceed for further. If your welds are qualified based on your requirements you can proceed.

Regarding UT, as the thickness is Low you need to make Amplitude comparison acceptance criteria. You must have a special make small size probes. Smaller than 8X9. And make sure you are scanning beam path must be in the focusing area or far field.

Once all people accept your procedure you can proceed

 
12:31 Sep-18-2018

Wieslaw Bicz

Engineering,
PBP Optel sp. z o.o.,
Poland,
Joined Feb 2009
239
Re: What is the Minimum thickness limit for manual UT In Reply to Sri Krishna at 00:20 Sep-18-2018 .

From the point of view of physics, the measurement of thin walls has no thickness limits, but it would be difficult to make such measurements manually, since it is necessary to generate waves, that are propagating parallel to the surface of wall. This can be done with critically refracted waves, generating so called subsurface waves. Such waves can be used for testing welds of thin walled pipes, are also used for testing stresses in material (Lcr waves - quite popular since some time). We have made our first industrial system for such testing welds on pipes with 1.5 mm wall thickness many years ago and for other application tested even the possibility to test very thin metal foils with a good result. Using this type of waves manually would require careful work. Is not impossible, but difficult.

 


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