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 -
961 views
Technical Discussions
Biju Varghese
Biju Varghese
11:36 Jun-15-2009
Tandem testing of LSAW/Spiral Pipes



I would like to have views regarding tandem testing for mid wall defect in longitudinal/Spiral SAW pipes as per Shell specification (DEP 31.40.20.37 annex d) for automated UT testing in pipe mill. As per the specification we have to use only 45 deg shear wave probe for transmitter and receiver probe. The problem we face is that the reflected angle from inner surface changes depending on the thickness to diameter ratio of pipe and hence to use receiver probe with same angle is not possible. Because of the change in the angle of the returning beam that bounces off the inside diameter of the pipe, the received angle (with respect to the outside surface) will not be the same as the transmitted angle. The skip distance will also change depending on t/D ratio.
As per our trials we have found results are very good with 60/70 deg combination for transmitter and receiver probe depending on t/D ratio of pipe. With 45/45 deg combination we are unable get the results. Why code specs only to use only 45 (± 3) deg probe for both transmitter and receiver?

 
 Reply 
 
Ed Ginzel
R & D, -
Materials Research Institute, Canada, Joined Nov 1998, 1282

Ed Ginzel

R & D, -
Materials Research Institute,
Canada,
Joined Nov 1998
1282
13:44 Jun-15-2009
Re: Tandem testing of LSAW/Spiral Pipes
In Reply to Biju Varghese at 11:36 Jun-15-2009 (Opening).

Biju...API5L is a common standard for Line Pipe and other national and international standards are similar. In the Standard there is no restriction on refracted angle to be 45 degrees. It could be that the person responsible for the company "specification" did not make provision for more effective inspections. API5L in 9.7.4.1 indicates that ANY equipment may be used. However, when used in the pulse-echo mode, it will be very difficult for an operator to correctly position the probes for the midwall region with any angle when required to use the notches or even the through hole because the "maximum amplitude" will generally be from the corner at either the ID or OD. To address this and get midwall coverage, the company I used to work for made a specification to use a calibration standard that used flat bottom holes aligned with the weld centreline in addition to the 1.5mm diameter through hole. Your suggestion for a tandem configuration would be a good option for a "practical solution" to the problem. A description of our concerns in 1998 was made in an article on NDT.net http://www.ndt.net/article/v04n11/eginzel/eginzel.htm
If the client is responsible for setting a specification that limits the efficacy of the guidelines set by the Standard then I would suspect they are also responsible for the outcome.

 
 Reply 
 

Product Spotlight

MUSE Mobile Ultrasonic Equipment

The MUSE, a portable ultrasonic imaging system, was developed for in-field inspections of light-weig
...
ht structures. The MUSE consists of a motor-driven manipulator, a water circulation system for the acoustic coupling and a portable ultrasonic flaw detector (USPC 3010). The MUSE provides images of internal defects (A-, B-,C- and D-scan).
>

Immersion systems

ScanMaster ultrasonic immersion systems are designed for high throughput, multi shift operation in a
...
n industrial or lab environment. These fully integrated systems provide various scanning configurations and incorporate conventional and phased arrays technologies to support diverse applications, such as inspection of disks, bars, shafts, billets and plates. All of ScanMaster immersion systems are built from high accuracy scanning frames allowing for scanning of complex parts and include a multi-channel ultrasonic instrument with exceptional performance. The systems are approved by all major manufacturers for C-scan inspection of jet engine forged discs. Together with a comprehensive set of software modules these flexible series of systems provide the customer with the best price performance solutions.
>

ISONIC 3510

Very Powerful Superior Performance Extremely Portable Smart Phased Array Ultrasonic Flaw Detector an
...
d Recorder with 2 Conventional UT and TOFD Channels uniquely combines PA, single- and multi-channel conventional UT, and TOFD modalities providing 100% raw data recording and imaging. Suitable for all kinds of every-day ultrasonic inspections
>

NOVO Armor 15 & NOVO Armor 22

The Armor Kit Contains the NOVO Armor, which provides additional mechanical protection to the NOVO 1
...
5WN & NOVO 22WN Detectors, the Armor Stand and a traveling soft cover. - Newest shock absorbent technology case - Water resistant design - Supports wired & wireless communication - Multiple positioning options - Tripod connection using the Built-in 1/4” threads - Simple Detector battery replacement
>

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