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Controle Mesure Systemes
Contrôle Mesure Systèmes designs, develops and manufactures nearly 30 years a complete NDT range of products in eddy current and ultrasonic testing methods.

3318 views
03:06 Jun-04-2003

Posma M. Pakpahan

NDT Inspector
PT. Pupuk Kaltim Tbk,
Indonesia,
Joined Jun 2003
4
Bimetallic Tube Inspection

Dear All,

We have a HP. Stripper in Urea Plant licensed by Snaphrogetti which have tubes made from bimetallic material ( Stainless steel + Zr ). Any of you could inform me the best method to be used to inspect the internal of that tube ? Thank you.


 
09:10 Jun-04-2003

fabio mussa

Engineering,
SAIPEM SpA,
Italy,
Joined Dec 2002
9
Re: Bimetallic Tube Inspection dear friend
the best solution to inspect bimetallic tubes is by eddy current
try to find some paper on ndt.net


: Dear All,
.
: We have a HP. Stripper in Urea Plant licensed by Snaphrogetti which have tubes made from bimetallic material ( Stainless steel + Zr ). Any of you could inform me the best method to be used to inspect the internal of that tube ? Thank you.
.



 
06:31 Jun-04-2003

John Hansen

Director, - Eddy Current Technology
ETher NDE Ltd,
United Kingdom,
Joined Oct 1999
71
Re: Bimetallic Tube Inspection Hi Fabio

I'm not familair with this tube configuration.

In order to evaluate the possibilty of using any NDT technique there is a lot of information that would be usefull
Internal diameter
Wall thickness of materials (which is on the inside)
Length
Type of defects to be detected and size

My opinion would be that providing you weren't interested in only circumferential cracks or laminations then an eddy current test with a differentail id probe would be the answer (in terms of speed and cost effectivenses) possibly backed up with an IRIS test. However there is a great deal I do not know about your applcation.

Rgds

John Hansen
www.hocking.com


 
07:00 Jun-04-2003

Rich Roberts

Engineering, Executive Managment
Quest Integrity Group,
USA,
Joined Nov 1998
78
Re: Bimetallic Tube Inspection

Dear Posma M. Pakpahan,
Additional information is needed in order to select the proper NDT technique for your specific application. There are many types of tube inspection techniques available (e.g. LOTIS-laser, ET, RFT, MFL, IRIS, etc.) however each technique works differently and is any could possible solve your problem. If you could supply the following information, I believe you could be directed in the right direction:
- Tube Diameter
- Tube Thickness
- Tube Length
- Failure Mechanisms Sought After

Kind Regards,
Rich



 
03:43 Jun-05-2003

Posma M. Pakpahan

NDT Inspector
PT. Pupuk Kaltim Tbk,
Indonesia,
Joined Jun 2003
4
Re: Bimetallic Tube Inspection Dear Friends,

Well, thank you very much for the kindly respond. The details of the tube :
- Material : 25-22-2 Cr/Ni/Mo + Zr
- Dimension : 28.8 mm OD x ( 2.0 mm + 0.7 mm ) Thick
x 5970 mm Length
- Total : 1852 Ea

This equipment is on the new plant with less than 1 yrs operating time and no failures before, the purpose of inspection is to make sure there is no general corrosion or thinning on the inside surface which made from Zr, therefore the result of inspection must be shown the remaining thickness of that Zr material. Thank you.


 
02:28 Jun-05-2003

Joe Buckley,

Consultant, ASNT L-III, Honorary Secretary of BINDT
Level X NDT, BINDT,
United Kingdom,
Joined Oct 1999
509
Re: Bimetallic Tube Inspection Based on the assumption that you are looking for thinning of the Zr layer (i.e. quite a small fraction of the total, and are only looking to proove a point (so that a small sample of representative tubes should be adequate) I would suggest that an IRIS technique is likely to be most appropriate.

Joe Buckley

: Dear Friends,
.
: Well, thank you very much for the kindly respond. The details of the tube :
: - Material : 25-22-2 Cr/Ni/Mo + Zr
: - Dimension : 28.8 mm OD x ( 2.0 mm + 0.7 mm ) Thick
: x 5970 mm Length
: - Total : 1852 Ea
.
: This equipment is on the new plant with less than 1 yrs operating time and no failures before, the purpose of inspection is to make sure there is no general corrosion or thinning on the inside surface which made from Zr, therefore the result of inspection must be shown the remaining thickness of that Zr material. Thank you.
.



 
04:48 Jun-05-2003

Rich Roberts

Engineering, Executive Managment
Quest Integrity Group,
USA,
Joined Nov 1998
78
Re: Bimetallic Tube Inspection Dear Posma M. Pakpahan
Based upon the information provided in your last entry, I believe that either the LOTIS laser process or the IRIS process would be the best solution to your problem. The LOTIS is about twice as fast as the IRIS, however is limited to interior flaws only. Since you appear to only be interested in very small internal erosion, corrosion and pitting the LOTIS can supply you with inspecton test result accuracy’s of +/-0.0508mm (0.002”). Please let me know if you would require additional information on either LOTIS or IRIS.
Kind Regards,
Rich



 
06:29 Jun-05-2003

fabio mussa

Engineering,
SAIPEM SpA,
Italy,
Joined Dec 2002
9
Re: Bimetallic Tube Inspection Dear friend
Lot of eddy current inspection have been carried out on bimetallic tubes, in order to detect corrosion from inside ( carbamate side) and to detect disbonding between two material.
i think, all eddy current NDT companies, are able to perform this kind of inspection.
Sure with :
Force technologies - denmark
Donegani Anticorrosione - italy

best regards
.



 
06:10 Nov-27-2003
g l kelkar
Re: Bimetallic Tube Inspection
We have recently observed tube seperation in bimetallic tube stripper tube for Urea service. What can be the reason?


 
07:35 Mar-07-2005
R. Gopal
Re: Bimetallic Tube Inspection Dear Friend:

Zr lined 25-22-2 tubes also encounter the following defects.
1. Zr layer projecting out at bottom side of HP Stripper (indicative of de bonding)
2. Active surface corrosion of 25-22-2 tube Outside dia at projected portions at bottom channel head
2. Active surface attack of 25-22-2 TTS welds which may develop leak in service

(We had serious problem in bimetallic stripper and hence went back to Ti tube bundle again within 2 yrs of operations).

NDT technique whether IRIS Or Eddy Current

It should indicate thickness of both Zr layer & that of 25-22-2 tube within 5% tolerance.
Defects in Zr layer like Wringles, crack, linear opening to be accurately indicated.
TTS welds condition to be assessed by special probes.
Tube sheet overlay 25-22-2 surface corrosion due to "Active" attack to be assessed.

NDT personnel with real authenticity for the above achievemnt of results shall contact me also.

Thanks & regards

R. Gopal


:
Dear All,
.
: We have a HP. Stripper in Urea Plant licensed by Snaphrogetti which have tubes made from bimetallic material ( Stainless steel + Zr ). Any of you could inform me the best method to be used to inspect the internal of that tube ? Thank you.
.



 


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