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 -
1242 views
Technical Discussions
krish
krish
12:07 May-06-2009
Acoustic emission testing of HIC affected pressure vessel

I would like to have the expert opinion about real time monitoring of Hydrogen Induced Cracking in a glass flake lined pressure vessel using Acoustic Emission Testing if condition favours to use the technique. Is it possible to detect step wise cracking & blister growth?

regards,

 
 Reply 
 
bob sudharmin
Engineering, Reliability and Integrity Eng
Shell Malaysia Trading, Malaysia, Joined Jan 2008, 54

bob sudharmin

Engineering, Reliability and Integrity Eng
Shell Malaysia Trading,
Malaysia,
Joined Jan 2008
54
17:08 May-06-2009
Re: Acoustic emission testing of HIC affected pressure vessel
In Reply to krish at 12:07 May-06-2009 (Opening).

Interesting question. I am no expert in this field, but what I understand is that Acoustic Emission listens to corrosion activity and hence translates to possible loss of metal or even leaks.
Its also interesting to know about Hydrogen Induced Cracking which normally happens in a non coated pressure vessel and how this can happen in a glass flake lined vessel.
For step wise cracking & blister growth, Ultrasonics would still be the best detection and monitoring procedure, and surely I would also like to know more of whether AE is also capable of doing this

 
 Reply 
 
Roger Duwe
NDT Inspector, API-510, 570, 653
MISTRAS, USA, Joined Jan 2009, 148

Roger Duwe

NDT Inspector, API-510, 570, 653
MISTRAS,
USA,
Joined Jan 2009
148
23:23 May-06-2009
Re: Acoustic emission testing of HIC affected pressure vessel
In Reply to bob sudharmin at 17:08 May-06-2009 .

I'm a 'user', not a subject expert.

Blister growth = Maybe

Stepwise, or any other crack propagation = Absolutely! This assumes that it is possible to stress the vessel, by pressuring it up to a psi at least 10% about the highest it has seen in the last year or so.

20 or 40% above the last highest pressure used at will give much better results. What you are doing is listening for flaws to propagate under the increased stress. The more [safe] stress, the better, and the smaller defects that can be identified.

 
 Reply 
 
John O'Brien
Consultant, -
Chevron ETC , USA, Joined Jan 2000, 280

John O'Brien

Consultant, -
Chevron ETC ,
USA,
Joined Jan 2000
280
21:31 May-07-2009
Re: Acoustic emission testing of HIC affected pressure vessel
In Reply to Roger Duwe at 23:23 May-06-2009 .

There was a report on work I think published by NACE a number of years ago that looked at the ability of AE to detect activity from HIC. Basically any propogation of the blister towards a step or the step cracks themselves will generate AE. Since then a number of people have monitored vessels with some success. A large amount of the hydrocarbon industry vessel population is made for SA 516 Grade 70 and this is a 'quiet' steel so density and placement of sensors can be crucial. Be aware that permenet moniroing may be more effective for results than 'intervention' testing by raising pressure.

Interetsing that this is an internally lined vessel and you still have HIC. Since you presumably have access to teh external surface I would still wonder why you are not AUT mapping the affected area or is your suspected hydrogen charging rate so high you fear rapid propogation.

 
 Reply 
 
krish
krish
10:13 May-08-2009
Re: Acoustic emission testing of HIC affected pressure vessel
In Reply to John O'Brien at 21:31 May-07-2009 .

Thanks john and other for the expert comments.We did AUT scan and TOFD and found laminar type of indication at the mid wall of the plate close to the L-Seam/C-Seam welds.Originally the vesseal was coated with Coal Tar epoxy and latter it was upgraded with Glass flake vinyl ester.Thro AE we want to ensure whether the existing lamination/dense inclusion at the mid wall is growing or not in service.There is a possibility that it could be pre-existing manufacturing defect and hence it is operating under moderate H2S environment that we feels that the defective site will favor for hic to initiate.

 
 Reply 
 

Product Spotlight

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.
>

TESTD-PT SYSTEM

Pulse thermography is a non-contact test method that is ideal for the characterization of thin fil
...
ms and coatings or the detection of defects. With a remarquable short test time and a high detection sensitivity, the Telops TESTD-PT is the perfect tool for non- destructive testing. With such high frame rates, it is even possible to investigate highly conductive or diffusive materials.
>

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.
>

NDTkit RT

NDTkit RT, TESTIA's Digital Radiography software The NDTkit product line software for X-ray analysi
...
s. NDTkit RT is a software benefiting from the Ultis kernel which is dedicated to radiographic image analysis. It offers a set of tools and filtering processes to assist RT operators in finding relevant flaws.
>

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