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897 views
00:11 May-26-2005

Brian Hanni

Black & Veach,
USA,
Joined May 2001
2
Corrosion monitoring

My company is operating a facility whose processes involve a variety of highly toxic and corrosive chemicals. This facility has been in operation 10+ years. We are approaching a scheduled maintenance shutdown. During this extended shutdown we will have the opportunity to gain access to tank & piping systems that are normally very difficult to get to. We are looking for an inspection system that will provide corrosion profiles and ultimately provide service life information on these systems. The nature of the corrosion is localized corrosion cells on the inside. Ultrasonic thickness testing has proven to be ineffective due to scanning limitations. Misleading results occur as the transducer is placed next to but not over the corrosion cell.

Thank you for any suggestions.



 
01:08 May-26-2005

Godfrey Hands

Engineering,
PRI Nadcap,
United Kingdom,
Joined Nov 1998
281
Re: Corrosion monitoring ----------- Start Original Message -----------
: My company is operating a facility whose processes involve a variety of highly toxic and corrosive chemicals. This facility has been in operation 10+ years. We are approaching a scheduled maintenance shutdown. During this extended shutdown we will have the opportunity to gain access to tank & piping systems that are normally very difficult to get to. We are looking for an inspection system that will provide corrosion profiles and ultimately provide service life information on these systems. The nature of the corrosion is localized corrosion cells on the inside. Ultrasonic thickness testing has proven to be ineffective due to scanning limitations. Misleading results occur as the transducer is placed next to but not over the corrosion cell.
: Thank you for any suggestions.
------------ End Original Message ------------


Dear Brian,
Sounds like a potential application for Ultrasonic Guideed Waves in conjunction with conventional Ultrasonic Scanning in the areas identified.

Ultrasonic Guided Waves are actually ultrasonic waves that propagate along a pipe (at a fairly low frequency) for up to 200 feet or more, and can detect significant corrosion (e.g. which represent somethjing in the order of 2 to 3% of the total pipe cross section. The distance from the sensor to this area of concern can then be identified, and this permits a detailed manual ultrasonic scanning to be planned for that specific area.
The testing can work underneath insulation (but some insuloation needs to be removed to allow access for the sensor).
It is best if you contact SwRI in San Antonio, Texas, who will be able to schedule some testing for you in the USA, either themselves or through one of their sub-contractors.
Please contact me first, and I will forward your message to them.

Godfrey Hands



 
01:13 May-26-2005
Jim Knowles
Re: Corrosion monitoring ----------- Start Original Message -----------
: My company is operating a facility whose processes involve a variety of highly toxic and corrosive chemicals. This facility has been in operation 10+ years. We are approaching a scheduled maintenance shutdown. During this extended shutdown we will have the opportunity to gain access to tank & piping systems that are normally very difficult to get to. We are looking for an inspection system that will provide corrosion profiles and ultimately provide service life information on these systems. The nature of the corrosion is localized corrosion cells on the inside. Ultrasonic thickness testing has proven to be ineffective due to scanning limitations. Misleading results occur as the transducer is placed next to but not over the corrosion cell.
: Thank you for any suggestions.
------------ End Original Message ------------

Brian
This is a case for tailoring a non destructive testing inspection technique to the problem. Obviously we know the problemswith direct contact of a transducer over the top of a corrosion pit and the inabilty to accurately measure the true under lying thickness or depth of flaw. In our systems we have used focused / stand off transducers in different arrangements coupled to short scanning systems to produce B & C scans. We then can see the profile of the corrosion pits. If as you state there are limtations in thescanning area, then look at radiographic means todays imaging systes can give corrosion profiles, similarly EC system give superb results once the inspection technique has been thoroughly tested for that application.


 
02:17 May-26-2005
Richard Kazares
Re: Corrosion monitoring Our company (through Conam) can provide corrosion testing services using an EXTREMELY high speed scanning system known as the Large Structure Inspection (LSI) System. It is programmable - so the resolution can be tailored to the specific requirements of each application - and as scanning speeds are over 20 inches (1/2 Meter) per second - and data is captured as a C-Scan image (with numerical backup) - with ALL data retained for future reference - this might be the solution you are looking for.

I will send you some photos and video by direct e-mail.


----------- Start Original Message -----------
: My company is operating a facility whose processes involve a variety of highly toxic and corrosive chemicals. This facility has been in operation 10+ years. We are approaching a scheduled maintenance shutdown. During this extended shutdown we will have the opportunity to gain access to tank & piping systems that are normally very difficult to get to. We are looking for an inspection system that will provide corrosion profiles and ultimately provide service life information on these systems. The nature of the corrosion is localized corrosion cells on the inside. Ultrasonic thickness testing has proven to be ineffective due to scanning limitations. Misleading results occur as the transducer is placed next to but not over the corrosion cell.
: Thank you for any suggestions.
------------ End Original Message ------------




 
03:34 May-27-2005

John Pursley

R & D
Envision Product Design,
USA,
Joined Oct 1999
23
Re: Corrosion monitoring ----------- Start Original Message -----------
: : My company is operating a facility whose processes involve a variety of highly toxic and corrosive chemicals. This facility has been in operation 10+ years. We are approaching a scheduled maintenance shutdown. During this extended shutdown we will have the opportunity to gain access to tank & piping systems that are normally very difficult to get to. We are looking for an inspection system that will provide corrosion profiles and ultimately provide service life information on these systems. The nature of the corrosion is localized corrosion cells on the inside. Ultrasonic thickness testing has proven to be ineffective due to scanning limitations. Misleading results occur as the transducer is placed next to but not over the corrosion cell.
: : Thank you for any suggestions.
: Brian
: This is a case for tailoring a non destructive testing inspection technique to the problem. Obviously we know the problems with direct contact of a transducer overthe top of a corrosion pit and the inabilty to accurately measure the true under lying thickness or depth of flaw. In our systems we have used focused / stand off transducers in different arrangements coupled to short scanning systems to produce B & C scans. We then can see the profile of the corrosion pits. If as you state there are limtations in thescanning area, then look at radiographic means todays imaging systes can give corrosion profiles, similarly EC system give superb results once the inspection technique has been thoroughly tested for that application.
------------ End Original Message ------------

Brian,

We have a new system for internal corrosion inspection of pipelines. Take a look at http://cmosxray.com/PDFS/ScanTrack PL.pdf



 
01:51 Jun-05-2005
jimmy
Re: Corrosion monitoring ----------- Start Original Message -----------
as discussed about corrosion monitoring with guided wave u can only detect corrosion from a pipe with minimum 10 meter length gul is good for long distance pipe to find internal and external corrosion also for my experiance its good for pipeline corrosion monitoring also for vessels and tanks you can go for automated ultrasonic it will give an exact result even the tank is with full internal corrosion for external corrosion u r eyes is best tool to detect, with AUT u can go for A,B and C scan also topview, if u want more clarification send mail to me i will come back to u coz. iam doing both job togeter and we got very good experiance in this job
regards
jimmy


 


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