where expertise comes together - since 1996 -

The Largest Open Access Portal of Nondestructive Testing (NDT)

Conference Proceedings, Articles, News, Exhibition, Forum, Network and more

where expertise comes together
- since 1996 -
8086 views
Technical Discussions
Luis Ganhao
Engineering,
USA, Joined Sep 2008, 25

Luis Ganhao

Engineering,
USA,
Joined Sep 2008
25
16:23 Oct-22-2009
diference betwen planar and non planar defect

I have the following question why the ASME sec VIII do not specify any about undercut and RT examination consider this defect as a volumetric indication and most of the times is accepted, however with UT normally this indication is rejected so how a RT technician can determine the depth of the undercut thru RT film??? and how they can consider this indication as volumetric/nonplanar and no as planar and very detrimental from the point of view of fracture mechanics. UT normally can detect and size (length and heigth) and normally is rejected.

 
 Reply 
 
john harbert
john harbert
04:28 Oct-23-2009
Re: diference betwen planar and non planar defect
In Reply to Luis Ganhao at 16:23 Oct-22-2009 (Opening).

Sec VIII Div I UW : this would be considered in the catagory of elongated indications. It does not say volumetric. The accept/reject depends on the length of the "EI" and the thickness of the plate. AND NO. (Sec VIII Div I App 12) This is not "normally rejected" with UT. With UT it also depends on the thickness of the plates being welded (with regards to reference std), but primarally depends on the amplitude of the returned signal from the defect.
Theoretically, with UT, you could have a signal from undercut or slag running the entire length of a weld and not be rejectable if the amplitude of the signal does not reach 100% DAC (reference level).

Regards

 
 Reply 
 
chen zhiqiang
Teacher, - - engineering for
HEBEI UNIVERSITY COLLEGE OF Qlty.&Tech., China, Joined Oct 2009, 5

chen zhiqiang

Teacher, - - engineering for
HEBEI UNIVERSITY COLLEGE OF Qlty.&Tech.,
China,
Joined Oct 2009
5
05:45 Oct-24-2009
Re: diference betwen planar and non planar defect
In Reply to john harbert at 04:28 Oct-23-2009 .

For the undercut defect, you can refer to the Visul inspection criteria,not only the length,but also depth and type.as you know,some under cut is sharp, some with U type.so whether to accept or not you can decide.

 
 Reply 
 

Product Spotlight

IRIS 9000Plus - Introducing the next generation of heat exchanger inspection.

Representing the seventh generation of the IRIS system, the IRIS 9000 Plus has nearly 200 years of c
...
ombined field inspection experience incorporated in its design. This experience combined with a strong commitment to quality and a history of innovation has made Iris Inspection Services® the undisputed leader in IRIS technology.
>

TraiNDE UT

TraiNDE UT is a virtual tool associated with a signal database which simulates real inspection con
...
ditions for numerous applications (Type A/V1 block, DAC block, welds and plates).
>

Teletest Focus+

Teletest Focus+ electronics have superior capabilities than rivals on the market. Beyond the usual
...
test features, Focus+ has 24 transmit channels and 24 receive channels, with an additional on-board switching capabilities. The instrument's frequency range is 10–300 kHz.
>

Cygnus 6+ PRO Multi-Mode Ultrasonic Thickness Gauge

The Cygnus 6+ PRO thickness gauge is the most advance gauge within the Cygnus range with key featu
...
res including: comprehensive data logging; A-scan and B-scan display; manual gain control; Bluetooth connectivity; and much more. With its unique dual display and three measuring modes (Multiple-Echo, Echo-Echo and Single-Echo), this surface thickness gauge offers maximum versatility for inspections.
>

Share...
We use technical and analytics cookies to ensure that we will give you the best experience of our website - More Info
Accept
top
this is debug window