Hydrogen blistering of pressure vessel shells can occur in process environments that cause hydrogen to diffuse through and “charge” the shell material with hydrogen. Process…
Category: In-Service Inspection
Hydrogen attack can occur in carbon steel and low-alloy Cr – Mo steels at elevated temperatures in process environments that contain a relatively high partial…
Internal erosion can occur when high velocity process streams come in contact with the vessel shell. Entrainment of solid particles in the fluid stream and…
Stress corrosion cracking can be a very serious form of deterioration that can result in the catastrophic failure of a pressure vessel. It is highly…
Corrosion fatigue is the nucleation of fatigue cracks at the stress concentrations associated with corrosion pits and/or the acceleration of fatigue crack growth by the…
Thermal fatigue is attributable to cyclic stresses similar to mechanical fatigue but differs in that the stresses are developed by temperature gradients (i.e., thermal stresses).…
Mechanical fatigue, caused by cyclic stresses, is likely to occur when the vessel has experienced at least 400 stress (pressure) fluctuations that exceed 15% of…
Austenitic stainless steels in service at temperatures above approximately 800°F can become sensitized to intergranular corrosion. This is similar to the knife-line-attack referred to in…
Low-alloy 1¼ Cr – ½ Mo steel is susceptible to creep embrittlement when in service at temperatures above approximately 850°F. Weld heat affected zones usually…
Low-alloy Cr – Mo steels are susceptible to temper embrittlement after long time operation at temperatures above approximately 700°F, which can result in severely reduced…