A vessel's shell has a current thickness of 0.525" and is corroding at 0.003 ipy. What thickness should be used to calculate the maximum allowed pressure for a 10-year inspection interval?

A vessel's shell has a current thickness of 0.525" and is corroding at 0.003 ipy. What thickness should be used to calculate the maximum allowed pressure for a 10-year inspection interval?

• A. 0.465"
• B. 0.495"
• C. 0.522"
• D. 0.525"

Answer: (A)

To determine the thickness that should be used for calculating the maximum allowed pressure over a 10-year inspection interval in the context of pressure vessel inspection, it's essential to account for the existing corrosion rate. In this scenario, the current thickness of the vessel's shell is 0.525 inches and it is corroding at a rate of 0.003 inches per year. Over a 10-year period, the total amount of corrosion that will occur can be calculated by multiplying the corrosion rate by the number of years. This gives us: 0.003 inches/year * 10 years = 0.030 inches To find the effective thickness that should be considered when calculating maximum allowed pressure, this calculated corrosion amount needs to be subtracted from the current thickness: 0.525 inches (current thickness) - 0.030 inches (corrosion over 10 years) = 0.495 inches Therefore, this adjusted thickness (0.495 inches) reflects the condition of the vessel after accounting for expected corrosion over the inspection interval and should be used to determine the maximum allowable pressure. Using this thickness for calculations ensures compliance with safety standards and provides a margin for reliability and safe operation of the pressure vessel throughout its service life.

To determine the thickness that should be used for calculating the maximum allowed pressure over a 10-year inspection interval in the context of pressure vessel inspection, it's essential to account for the existing corrosion rate. In this scenario, the current thickness of the vessel's shell is 0.525 inches and it is corroding at a rate of 0.003 inches per year.

Over a 10-year period, the total amount of corrosion that will occur can be calculated by multiplying the corrosion rate by the number of years. This gives us:

0.003 inches/year * 10 years = 0.030 inches

To find the effective thickness that should be considered when calculating maximum allowed pressure, this calculated corrosion amount needs to be subtracted from the current thickness:

0.525 inches (current thickness) - 0.030 inches (corrosion over 10 years) = 0.495 inches

Therefore, this adjusted thickness (0.495 inches) reflects the condition of the vessel after accounting for expected corrosion over the inspection interval and should be used to determine the maximum allowable pressure.

Using this thickness for calculations ensures compliance with safety standards and provides a margin for reliability and safe operation of the pressure vessel throughout its service life.