MDMT

Minimum Design Metal Temperature (MDMT) is the LOWEST temperature that the vessel may be operated at (in other words, you must operate the vessel at a temperature higher than MDMT). The MDMT marked on the nameplate shall correspond to a coincident pressure equal to the MAWP. When there are multiple MAWP's, the largest value shall be used to establish the MDMT marked on the nameplate, though additional MDMT's corresponding with other MAWP's may also be marked on the nameplate.