Topic Options
#7357 - 11/30/05 07:07 AM MDMT
manojkumar Offline
Member

Registered: 11/28/05
Posts: 5
Loc: mumbai
Can any one help me on following
1)What Is MDMT and Its enfluence in design calculations?
I would also like to know method to calculate MDMT of any Metal as per ASME
_________________________
manojkumar

Top
#7358 - 12/06/05 04:35 AM Re: MDMT
abhijit d Offline
Member

Registered: 12/06/05
Posts: 6
Loc: ---
Hello manojkumar
MDMT is obviously minimum design metal temperature.It is the lowest temperature upto which that particular material can be used without impact testing.It means it should not be more than minimum design temperature.
MDMT can be calculated as per UCS-66 of ASME Sec VIII div 1.As per the relevent curve(A,B,C or D) of the material used and the nominal thickness of shell/head,the graph gives MDMT on y-axis.
Regards,
Abhijit Dutta
_________________________
abhijit

Top
#7359 - 01/25/06 10:28 AM Re: MDMT
Jack Offline
Member

Registered: 01/25/06
Posts: 2
Loc: calgary
Hi abhijit
just a comment, depending upon process, engineer will select MDMT for the equipment. At that particular value, one can check from UCS-66, if impact test is required
_________________________
Jack

Top
#7360 - 02/09/06 01:54 AM Re: MDMT
abhijit d Offline
Member

Registered: 12/06/05
Posts: 6
Loc: ---
Hi jack
thanks for the comment.For more clarity to manoj it is like that.
Due to process reason if the minimum temperature is going below MDMT then impact testing is required.
--------------
abhijit
_________________________
abhijit

Top
#7361 - 03/30/06 12:01 AM Re: MDMT
manojkumar Offline
Member

Registered: 11/28/05
Posts: 5
Loc: mumbai
Thank you all for your kind attention.

Regards
_________________________
manojkumar

Top
#7362 - 03/30/06 06:44 AM Re: MDMT
Ray_Delaforce Offline
Member

Registered: 01/02/03
Posts: 743
Loc: Houston, TX
Hello folks

When low temperature is to be encountered, and the material of construction is carbon steel (eg: SA 516 70) remember to order it in the normalised condition - especially if it is over 1/2 inch (12 mm) thick.
_________________________
Sincerely,
Ray Delaforce
CADWorx & Analysis Solutions
Hexagon PPM

Top
#7363 - 04/29/06 02:39 PM Re: MDMT
Mahesh Offline
Member

Registered: 04/11/06
Posts: 16
Loc: Mumbai, India
Dear Ray Delaforce,

Whats the adantage of ordering carbon steel material in normalised condition for low temperature application.

Mahesh
maheshpatelgg@yahoo.com
_________________________
Mahesh Patel

Top
#7364 - 05/01/06 06:06 AM Re: MDMT
Ray_Delaforce Offline
Member

Registered: 01/02/03
Posts: 743
Loc: Houston, TX
Hello Mahesh

If you look at ASME Section VIII, Division 1, paragraph UCS-66 and the accompanying graph you will see the advantage. Graph USC-66 has four curves labeled A, B, C and D. If you have a material that qualifies as a curve D material, you can see that it can be subjected to a lower temperature than a curve A material. Let us look at an example.

Suppose we have a 1 inch thick plate. If treated as a curve A material, we can go down to 68 degrees F before impact testing is required. But, if the 1 inch plate can be treated as a curve D material we can go down to minus 30 degrees F before impact testing is required.

The lowest temperature to which a component can be subjected is called the MDMT or: Minimum Design Metal Temperature.

Now, an SA 516 70 plate in the un-normalised condition can be treated as a curve B material. If the plate is normalised, it can be treated as a curve D material.

To avoid having to impact materials, it is better that the MDMT of the material is lower on the UCS-66 graph.
_________________________
Sincerely,
Ray Delaforce
CADWorx & Analysis Solutions
Hexagon PPM

Top
#7365 - 05/02/06 02:49 AM Re: MDMT
kk Offline
Member

Registered: 06/24/05
Posts: 43
Loc: malaysia
Can anyone tell me why stainless stell material can go for very low temperature servise? and how low it can go, which paragraph in ASME code book should i look for it?

Thanks
_________________________
kkchong

Top
#49104 - 06/03/12 11:06 PM Re: MDMT [Re: manojkumar]
ankitipr Offline
Member

Registered: 04/30/12
Posts: 2
Loc: India

Hello eveyone,

Is MDMT really relevant for SA-321 material? and what one should do to remove the error if it's coming below the specified value (-29 C in my case).

Ankit

Top



Who's Online
0 registered (), 109 Guests and 3 Spiders online.
Key: Admin, Global Mod, Mod
May
Su M Tu W Th F Sa
1 2 3 4
5 6 7 8 9 10 11
12 13 14 15 16 17 18
19 20 21 22 23 24 25
26 27 28 29 30 31
Forum Stats
12065 Members
14 Forums
16973 Topics
75151 Posts

Max Online: 303 @ 01/28/20 11:58 PM
Top Posters (30 Days)