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 -

2259 views
Technical Discussions
jason hewett
jason hewett
03:30 Jun-19-2008
lamination vs stringer

My client has specs for welding close to laminations but none in regards to stringers. I'm currently inspecting 12" x 6.4mm late 1950s pipe that is full of inclusions/stringers. It's not much of an issue when doing a tie in on dead pipe, but welding line stoppers (fillet welds) onto live pipe with stringers present is making me nervous. Should I have cause for concern?

Cheers

Jason


 
 Reply 
 
Ryan Burns
Ryan Burns
06:24 Jun-20-2008
Re: lamination vs stringer
Hi Jason,

My opinion is that it would depend on the depth of the stringers. What is the product and pressure in the line? If you are finding multiple indications at varying depths in the area of the anchor welds, then yes, I'd be concerned. Is there any chance you may be seeing HIC (Hydrogen Induced Cracking)? Have you done shearwave to find any step cracks? I'd also suggest using a delay line transducer to ensure near surface indications are not missed, as well as black on white MT to ensure there is no SCC present.

Good luck,

Ryan

----------- Start Original Message -----------
: My client has specs for welding close to laminations but none in regards to stringers. I'm currently inspecting 12" x 6.4mm late 1950s pipe that is full of inclusions/stringers. It's not much of an issue when doing a tie in on dead pipe, but welding line stoppers (fillet welds) onto live pipe with stringers present is making me nervous. Should I have cause for concern?
: Cheers
: Jason
------------ End Original Message ------------




 
 Reply 
 
David Hermanutz
Consultant,
Hbndt.com, China, Joined Jul 2012, 85

David Hermanutz

Consultant,
Hbndt.com,
China,
Joined Jul 2012
85
01:55 Aug-22-2008
Re: lamination vs stringer
Hi Jason,

Hot Taps on live lines need to have good material, I have rejected pipe three times in a row for stringers, Like you , I also had no direction on Laminations but felt that it was neccessary to go with caution.

If the pipe is excessively "dirty" it may also have unknown material properties such as High Carbon that could lead to cracking and failure of the hot-tap procedure. Old pipe manufacturing had a ridiculously low amount of Quality Assurance performed, and may not be fit for the service it has been operating under.

Be safe!

David

Regards,

David

----------- Start Original Message -----------
: Hi Jason,
: My opinion is that it would depend on the depth of the stringers. What is the product and pressure in the line? If you are finding multiple indications at varying depths in the area of the anchor welds, then yes, I'd be concerned. Is there any chance you may be seeing HIC (Hydrogen Induced Cracking)? Have you done shearwave to find any step cracks? I'd also suggestusing a delay line transducer to ensure near surface indications are not missed, as well as black on white MT to ensure there is no SCC present.
: Good luck,
: Ryan
: : My client has specs for welding close to laminations but none in regards to stringers. I'm currently inspecting 12" x 6.4mm late 1950s pipe that is full of inclusions/stringers. It's not much of an issue when doing a tie in on dead pipe, but welding line stoppers (fillet welds) onto live pipe with stringers present is making me nervous. Should I have cause for concern?
: : Cheers
: : Jason
------------ End Original Message ------------




 
 Reply 
 

Product Spotlight

Extended Range Variable Wall® Piping Calibration Blocks for Longseam Inspection

This set of two blocks has been specially designed for situations where ultrasonic examination tak
...
es place circumferentially or “around the curve” for applications such as inspection of longseam welds in piping and vessels. Jointly designed by PH Tool and Holloway NDT, the blocks feature side-drilled hole reflectors positioned within novel compound-curves, each with multiple thickness steps. The unique design results in a light and compact form factor, with the largest block weighing just over 15 lbs and spanning just 16 ¾”. Coverage is provided for nominal pipe sizes from 6” to 10” in the small block and 12” to a whopping 56” in the large block. The compound OD curves and multiple wall thicknesses actually exceed ASME requirements, providing exceptional signal response and measurement accuracy. Properly managing beam divergence off the ID and stabilizing beam skew due to probe rocking is essential to maintaining a consistent calibration when inspecting lengthwise on curved surfaces.
>

NDT.net launches mobile-friendly design

NDT.net has revamped its website providing a mobile-friendly design.The front page received a comp
...
letely new design and all other sections are now reacting responsively on mobile devices. This has been a major step to make our website more user- friendly.
>

A1525 SOLO

A1525 Solo – the most compact and affordable TMF unit with two phased array transducers and 3D v
...
isualization and analysis software in standard delivery set. A compact, ergonomic and easy to handheld Phased Array unit based on Total Focusing Method for easy-going imaging of inspection objects with two-dimensional and three-dimensional visualization and evaluation of inspection results.
>

Compact NDT inspection-heads for measurements with active thermography

The compact inspection head is suitable for thermographic ndt tasks. The uncooled infrared camera
...
is specially developed for NDI-tasks and offers a thermal sensitivity until now known only from thermal imagers with cooled detector. All required components and functions are integrated into the inspection-head. You will only need an ethernet cable to connect the sensor with the evaluation system.
>

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