Pay particular attention to figures and tables within API RP 571.
Equipment that is temper embrittled may be susceptible to brittle fracture during start-up and shutdown
Some reduction in the likelihood of a brittle fracture may be achieved by PWHT
Generally, an increase of about 25°F (12°C) or an increase of 15% on stress can cut the remaining creep life in half or more
Cracking of dissimilar metal welds occurs in the Ferritic (carbon steel or low alloy steel) side of a weld
Cavitating pumps may sound like pebbles are being thrashed around inside
The signature mark of a fatigue failure is a “clam shell” type fingerprint that has concentric rings called “beach marks”
UT thickness gauging are very effective methods for detecting galvanic corrosion
Corrosion Under Insulation (CUI) becomes more severe at metal temperatures between the boiling point 212°F (100°C) and 350°F (121°C).
Corrosion protection in the boiler is accomplished by laying down and continuously maintaining a layer of protective Fe3O4 (magnetite).
Carbon steel may suffer deep pitting and grooving in areas of turbulence.
Piping with stagnant or low flow, and piping in contact with soil may cause Microbiologically Induced Corrosion (MIC)
Soil resistivity depends on soil moisture content and dissolved electrolytes in the soil water.
Chromium is the primary alloying element that affects resistance to oxidation.
Sulfidation of iron-based alloys usually begins at metal temperatures above 500°F (260°C).
Nitriding begins above 600°F (316°C) and becomes severe above 900°F (482°C).
Alloys with nickel contents above 45% are nearly immune to Chloride Stress Corrosion Cracking (Cl-SCC) .
Nickel base alloys are more resistant to Caustic Stress Corrosion Cracking (Caustic Embrittlement)
Amine Corrosion is not caused by the amine itself, but the dissolved acid gases (CO2 and H2S).
Upgrading carbon steel to nickel base alloys or titanium can reduce HCl acid corrosion
Naphthenic Acid Corrosion (NAC) is a form of high temperature corrosion that occurs primarily in crude and vacuum units
Carbon steel Sulfuric Acid corrosion rates increase significantly if the flow velocity exceeds about 2 to 3 fps (0.6 to 0.9 m/s) or at acid concentrations below 65%.