Design MDMT Vs Rated MDMT
Design MDMT Vs Rated MDMT
(OP)
i wonder if any one can explain what is the differences between design MDMT and Rated MDMT? which one we use as base to determine if impact test is require for vessel or not?
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS Come Join Us!Are you an
Engineering professional? Join Eng-Tips Forums!
*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail. Posting GuidelinesJobs |
Design MDMT Vs Rated MDMT
|
RE: Design MDMT Vs Rated MDMT
RE: Design MDMT Vs Rated MDMT
Regarding how to lower you will need to review the code sections. It is a tricky subject which depends on many different factors.
How cold does your MDMT need to be? What type of material?
Your best bet to lower MDMT is to either use a material that is exempt to a cold temp like stainless steel (304, 316) or charpy impact test.
RE: Design MDMT Vs Rated MDMT
RE: Design MDMT Vs Rated MDMT
The "design" MDMT is that specified by the vessel owner. The "rated" MDMT is that found from applying the rules of ASME Code. For example, VIII-1, Figure UCS-66.2 is the flowchart diagram showing the rules for determining the lowest (coldest) MDMT without requiring impact testing. The concept is analogous to pressure: there is a "design" pressure specified by the vessel owner, and there is the "rated" MAWP found by applying the rules of the Code to determine the maximum pressure that the component(s) can sustain. In both cases, pressure and MDMT, there will be a governing component...that with the lowest pressure rating for chamber MAWP and that with the highest (warmest) temperature rating for the chamber MDMT.