MPI vs DPI
Amir Zakee Adnal
What is/are major difference between MPI and DPI? Can MPI be
substitute with DPI? Is there any code or standard that allow such
substitution?
Regards,
Amir Zakee
george....@gr.bureauveritas.com
Regards,
Amir Zakee
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mohammed helal
| The major difference is the DPI is only for the defects that open to the surface and the MPI for the subsurface defect ( 6 mm deep). Eng.MOHAMMED ABD EL-AZIM HILAL
MECHANICAL ENGINEER
CSWIP 3.1 - NDT (RT- MT - PT)
OTISHAN CONSULTANT ENGINEER
00966-502612218 - 0020103124557 --- On Tue, 6/29/10, george....@gr.bureauveritas.com <george....@gr.bureauveritas.com> wrote: |
Tran Van Vuong
Even opened surface defects, when dirt not to be moved sufficient it can not use DPI.
Regards,
TRAN VAN VUONG
NDT Level III according to SNT-TC-1A
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manoj john
Declan Foley
MPI is for ferromagnetic materials only. It is supposedly useful for defects of depth 6mm, but ask anyone who performs the tests and they will tell you it is not!
DPI can be conducted on any material. It is not recommended on materials that have porous surfaces such as castings and the like.
Strictly speaking they are both considered surface tests. As regards substituting one for the other, I have never come across any situation where you couldn't. What are you testing?
Declan
praful...@metso.com
Friends,
- Magnetic Particles Testing is USED on Metals can take Magnetic Field, like all Steel and Iron Except for Gamma Iron and Austenitic Steel be it Stainless Ni-Cr or Manganese Steel - Parts.
- It basically a surface discontinuity test.
- I would like to correct as DPI can also be tested on Castings of any metal and or its process of production by which such castings produced, to check the Cracks etc, it works on the Principle of Capillary action of Liquid.
- The Die is poured on test piece, to be checked, after its proper surface cleaning, some local grinding etc, then Colored die is applied.
- After that the DIEs poured/spread allowed to go in all crevices and possible discontinuities, we intend to check.
- Then after reasonably 5 to 15 minutes the same part/test PC/surface is cleaned with dry cloth of cotton and then surface is cleaned by WET rinsed Cloth/cotton.
- This removes the apparent surface color, once then the Developer the Chalk powder is sprayed over the entire surface.
- The Chalk powder acts as sets on the surface and tried to catch the hidden and deep die went in to deep, shallow cracks and discontinuities.
- On such places where defects observed as above described, we get surface COLORED, same as die color, other places remains White same as developer Chalk spread remains white.
- Colored area than dressed suitably and welded or repaired as per various needs after V notch by fiber/dics-DC Wheel on Flexible chain Grinders, for such welded repair subject to pre and post welding heat treatment, to comply metal integrity.
- In depth test can be other tests, like (A) Ultrasonic testing (B) Radio Graphic Testing for detailed defect analysis etc.
- Hope these meets with your needs to address your issues at this point of time.
PCP Rawal
Manager Material Development-Life Cycle Services
METSO Minerals (India) Pvt Ltd.
Foundry unit, Plot no. 611-612.
Odhav road, Opp. Vallabhnagar, Odhav,
AHMEDABAD 382415
Gujarat India
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| From: | Declan Foley <declan...@eircom.net> |
| To: | material...@googlegroups.com |
| Cc: | mohammed helal <eng_h...@yahoo.com> |
| Date: | 06/30/2010 02:21 PM |
| Subject: | Re: [MW:5800] MPI vs DPI |
| Sent by: | material...@googlegroups.com |
MALLIKARJUN SHAUKAR
basically both are superior visual testing ie indications are get magnified that can detect by naked eye easily.pt is ment for non porus metals mt is ment for ferrromagnetic(strongly attracted towords magetic field) materials.In mpi we can be used for surface and subsurface but pt is only for surface indications.In mt get result as fast (within min) compared pt(min 30 min.) In mt skill is necessory to perform mt compared to pt. --- |
Amir Zakee Adnal
We are doing some fabrication on normal carbon steel but we don't have
the MPI set at this moment. My client would like to have some NDT
tested. I need to convince my client that DPI is good enough to get
the fabrication tested.
Regards,
Amir Zakee
On 6/30/10, Declan Foley <declan...@eircom.net> wrote:
>
>
> MPI is for ferromagnetic materials only. It is supposedly useful for
> defects of depth 6mm, but ask anyone who performs the tests and they
> will tell you it is not!
>
> DPI can be conducted on any material. It is not recommended on materials
> that have porous surfaces such as castings and the like.
>
> Strictly speaking they are both considered surface tests. As regards
> substituting one for the other, I have never come across any situation
> where you couldn't. What are you testing?
>
> Declan
>
> On 29/06/2010 17:35, mohammed helal wrote:
>> The major difference is the DPI is only for the defects that open to
>> the surface and the MPI for the subsurface defect ( 6 mm deep).
>>
>> Eng.MOHAMMED ABD EL-AZIM HILAL
>> MECHANICAL ENGINEER
>> CSWIP 3.1 - NDT (RT- MT - PT)
>> OTISHAN CONSULTANT ENGINEER
>> 00966-502612218 - 0020103124557
>>
>>
>> --- On *Tue, 6/29/10, george....@gr.bureauveritas.com
>> /<george....@gr.bureauveritas.com>/* wrote:
>>
>>
>> From: george....@gr.bureauveritas.com
>> <george....@gr.bureauveritas.com>
>> Subject: Re: [MW:5791] MPI vs DPI
>> To: "materials-welding" <material...@googlegroups.com>
>> Date: Tuesday, June 29, 2010, 7:06 PM
>>
>> Mpi can be used only on ferromagnetic materials
>>
>>
>> ----- Original Message -----
>> From: Amir Zakee Adnal [amir...@gmail.com
>> <http://us.mc1138.mail.yahoo.com/mc/compose?to=amir...@gmail.com>]
>> Sent: 29/06/2010 16:52 ZE5
>> To: material...@googlegroups.com
>>
>> <http://us.mc1138.mail.yahoo.com/mc/compose?to=material...@googlegroups.com>
>> Subject: [MW:5787] MPI vs DPI
>>
>>
>>
>> Dear all
>> What is/are major difference between MPI and DPI? Can MPI be
>> substitute with DPI? Is there any code or standard that allow such
>> substitution?
>>
>> Regards,
>> Amir Zakee
>>
>> --
>> To post to this group, send email to
>> material...@googlegroups.com
>>
>> <http://us.mc1138.mail.yahoo.com/mc/compose?to=material...@googlegroups.com>
>> To unsubscribe from this group, send email to
>> materials-weld...@googlegroups.com
>>
>> <http://us.mc1138.mail.yahoo.com/mc/compose?to=materials-weld...@googlegroups.com>
>> For more options, visit this group's bolg at
>> http://materials-welding.blogspot.com/
>> The views expressed/exchnaged in this group are members personel
>> views and meant for educational purposes only, Users must take
>> their own decisions w.r.t. applicable code/standard/contract
>> documents.
>>
>> --
>> To post to this group, send email to
>> material...@googlegroups.com
>>
>> <http://us.mc1138.mail.yahoo.com/mc/compose?to=material...@googlegroups.com>
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mahendran p
Hi all,
I have to clarify regarding the MPI that can detect sub-surface. I can't see any code or std mention abt how much depth(6mm) can it detect the defects. Please inform me which std mention may i refer?
Thanks & regards,
|
Karthik
Hi,
Normal Detection depth in MT shall be 6mm.However maximum detection depth shall be 15mm Very large cracks can be found in normal practice.
But as per magnaflux(MT equipment manufacturer) recommendation Normal detection depth - 6mm.However 12mm to 25mm can be acheived.
Thanks & Regards,
(Karthik)
Karthikeyan.S
Getabec Energy Co.,Ltd.
379,Moo6,Soi8,Nikhomphatana,
Rayong-21180,
Thailand.
Phone: 0066 38 897035-8 (Off)
Fax: 0066 38 897034
Hand Phone: 0066 892512282 --- On Wed, 6/30/10, mahendran p <pmah...@yahoo.co.in> wrote: |
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Declan Foley
in general fabrication of mild steel, there is no reason why DPI can not
be used. It is actually a common enough practice ( you would rarely walk
into any fabrication shop without seeing some cans lying around). I'm
assuming the purpose is just for a general overview of weld quality such
as fillet welds and not as a substitute for penetration butt welds. MPI
& DPI in this instance perform the same basic function, and that is the
detection of surface defects.
Don't get confused by claims that MPI can detect subsurface - it can -
but interpretation is difficult and also subjective. If you are looking
for subsurface defects you use Radiographic or ultrasonic testing.
hope this helps
Declan