API 571-Temper Embrittlement Prevention / Mitigation Existing Materials

Temper embrittlement can not be prevented if the material contains _____________ and is exposed in the______________.

To minimize the possibility of brittle fracture during startup and shutdown, many refiners use a _____________ to limit system pressure to about _________ of the maximum design pressure for temperatures below a Minimum Pressurization Temperature (MPT). Note that MPT
is not a single point but rather a __________ which defines safe operating conditions to minimize the likelihood of brittle fracture.

MPT’s generally range from ________for the earliest, most highly temper embrittled steels, down to _________ for newer, temper embrittlement resistant steels (as required to also minimize effects of hydrogen embrittlement).

If weld repairs are required, the effects of temper embrittlement can be temporarily reversed (de-embrittled) by ______________, and __________. It is important to note that re-embrittlement will occur over time if the material is re-exposed to the __________.