What membrane stress, according to industry experience, is required to cause failure due to brittle fracture?

What membrane stress, according to industry experience, is required to cause failure due to brittle fracture?

• A. 6ksi
• B. 7ksi
• C. 10ksi
• D. 12ksi

Answer: (B)

The requirement for membrane stress to cause failure due to brittle fracture is critical in the design and evaluation of storage tanks. Industry experience indicates that a membrane stress level around 7 ksi is often cited as the threshold at which brittle fracture can occur in certain materials, particularly in older carbon steels and certain alloys used in pressure vessels and storage tanks. This stress level is significant because it reflects the material's toughness and impact resistance at operating temperatures, considering factors such as fatigue and environmental conditions. If operating stresses exceed this threshold, there is an increased risk of crack initiation and propagation, leading to catastrophic failure. Evaluating material properties and understanding stress limits are essential elements of maintaining storage tanks and ensuring safety. This is particularly relevant in the context of API 653 inspections, where the integrity of tanks is assessed for potential failure mechanisms, including brittle fracture, which could arise from inappropriate stress levels during service.

The requirement for membrane stress to cause failure due to brittle fracture is critical in the design and evaluation of storage tanks. Industry experience indicates that a membrane stress level around 7 ksi is often cited as the threshold at which brittle fracture can occur in certain materials, particularly in older carbon steels and certain alloys used in pressure vessels and storage tanks.

This stress level is significant because it reflects the material's toughness and impact resistance at operating temperatures, considering factors such as fatigue and environmental conditions. If operating stresses exceed this threshold, there is an increased risk of crack initiation and propagation, leading to catastrophic failure.

Evaluating material properties and understanding stress limits are essential elements of maintaining storage tanks and ensuring safety. This is particularly relevant in the context of API 653 inspections, where the integrity of tanks is assessed for potential failure mechanisms, including brittle fracture, which could arise from inappropriate stress levels during service.