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Sanjay Vadhaiya
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Minimum Design Metal Temperature (MDMT)

02/04/2009 4:24 AM

Please clear my concept of Minimum Design Metal Temperature(MDMT).

I have little confusion regarding MDMT.

Also please tell me what is its significance in Designing ?

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sb
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#1

Re: Minimum Design Metal Temperature

02/04/2009 4:46 AM

Please come out with your confusion and if the confusion is cleared then automatically you will know its significance in designing (which also includes anothe MDMT - Maximum Design Metal Temperature)

And if you want the value, please follow ASME section VIII, codes.

In fact the names of the terms are quite clear to what they mean.

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PWSlack
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#2

Re: Minimum Design Metal Temperature

02/04/2009 4:46 AM

Hydrogen exhibits metallic properties close to Absolute Zero, so the concept of MDMT needs to be stated in order to receive anything worthwhile from this posting.

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sb
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#3
In reply to #2

Re: Minimum Design Metal Temperature

02/04/2009 7:09 AM

put a when you comment like this or are you a or

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Abdel Halim Galala
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#4

Re: Minimum Design Metal Temperature (MDMT)

02/05/2009 1:46 AM

Like as affecting of higher temperature on mechanical properties of metal (like as tensile & elongation), also low and very low temperature has another effect on mechanical properties of metals (like as brittle fracture).

So, no way to use any specified metal at a temperature lower than its calculated MDMT, otherwise you have to proceed an impact test for that metal at that temp. and be sure that the results are in safe margin. And MDMT is determined and calculated based on type of metal itself and its thickness.

In accordance with ASME code, the metallic material is categorized by its P-Number & Group Number. Where the P-No. represents the grouping of material w.r.t. its weldability whereas the Gr.-No. represents and related to impact requirements of that metal.

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Abdel Halim Galala
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#5
In reply to #4

Re: Minimum Design Metal Temperature (MDMT)

02/05/2009 2:24 AM

For more details, please see ASME code, section VIII, Division 1, UG-84, UCS-65 and UCS-66.

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Abdel Halim Galala
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#8
In reply to #5

Re: Minimum Design Metal Temperature (MDMT)

08/28/2009 4:11 AM

• The attached file demonstrates how to calculate the lowest MDMT for a whole pressure vessel without impact testing as per ASME VIII-Div. 1: MDMT_Calculations_for_a_Pressure_Vessel

• See CR4 Threads Impact Test & SA 516 Grade 70 Steels

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MIKE86
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#13
In reply to #8

Re: Minimum Design Metal Temperature (MDMT)

06/13/2013 7:37 PM

I am not able to find this calculation, please provide download sources.

Thanks you much.
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Cemal Tardu
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#6
In reply to #4

Re: Minimum Design Metal Temperature (MDMT)

03/13/2009 9:59 AM

Hey guys, I think Mr.Galala devoured the ASME Code.

Thanks Abdel, again a good answer came from your side.

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Abdel Halim Galala
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#7
In reply to #6

Re: Minimum Design Metal Temperature (MDMT)

03/13/2009 11:49 AM

Thank you Cemal Tardu,

and you are welcome in CR4 forum.

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sarmad
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#9
In reply to #7

Re: Minimum Design Metal Temperature (MDMT)

09/01/2009 6:34 AM

GOOD ANSWER ABDULHALEM

بارك الله فيك ونشكرك على هذه المعلومات
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Abdel Halim Galala
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#10
In reply to #9

Re: Minimum Design Metal Temperature (MDMT)

09/01/2009 7:14 AM

Thank you sarmad شكرا لك سرمد

You are welcome مرحبا بك

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dhayanandhan
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#12
In reply to #9

Re: Minimum Design Metal Temperature (MDMT)

01/21/2013 4:17 AM

Dear Mr. Sarmad,

I cannot read Urdu. Pl. give me the translation, بارك الله فيك ونشكرك على هذه المعلومات

I amalso joining with you and other CR4 Forum Members to appreciate Mr. ABDUL HALEEM. Indeed, he is the ASME CODE.

Thanks,

DHAYANANDHAN.S
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dhayanandhan
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#14
In reply to #6

Re: Minimum Design Metal Temperature (MDMT)

02/20/2014 2:12 AM

Dear Mr.Cemal Tardu,

NO DOUBT. Mr.ABDEL HALIM GALALA IS a MASTER on PRESSURE VESSELS, ASME CODE.

I have learnt a lot through his POSTINGS/REPLY. Once I sent a Personal Thanks Message for clearing the doubt.

DHAYANANDHAN.S
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Syed7786
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Join Date: May 2011
Posts: 1
#11
In reply to #4

Re: Minimum Design Metal Temperature (MDMT)

05/29/2011 3:09 PM

I like your explanation Regarding MDMT. I have a question regarding MDMT.SA-516 Grade 60 @ 150 psi thickness=0.625" MDMT =-25 degree F and PWHT will be performed after repair. Does the replacement section require Impact Testing?

Could you let me know,

Thanks

Syed
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