Cathodic Protection in Materials Techniques Engineering
29 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the purpose of the continuous current source in the impressed current cathodic protection method?

  • To create a potential difference between the metal body and the ground bed
  • To convert the alternating current source into a direct current (correct)
  • To provide a steady flow of current to the metal body being protected
  • To control the amount of current being applied to the system
  • What is the purpose of the ground bed in the impressed current cathodic protection method?

  • To provide a source of current for the metal body being protected
  • To provide a path for the current to flow from the metal body to the ground
  • To control the amount of current being applied to the system
  • To act as the positive end of the current source (correct)
  • What is the purpose of burying the anodes in coke breeze backfill in the impressed current cathodic protection method?

  • To increase the surface area of the anodes
  • To control the amount of current being applied to the system
  • To provide a source of current for the metal body being protected
  • To reduce the anode-soil contact resistance (correct)
  • What is the purpose of using shallow ground beds in the impressed current cathodic protection method?

    <p>To provide a path for the current to flow from the metal body to the ground</p> Signup and view all the answers

    What is the purpose of using vertical ground beds in the impressed current cathodic protection method?

    <p>To reach the soil layers of low resistance</p> Signup and view all the answers

    What is the purpose of the whole structure being at one potential in cathodic protection?

    <p>To eliminate the need for anode and cathode sites</p> Signup and view all the answers

    What is the purpose of digging deep wells of the closed type in areas with very high specific resistance?

    <p>To reach the lower layers with small specific resistance</p> Signup and view all the answers

    What material is commonly used for sacrificial anodes in cathodic protection systems?

    <p>Magnesium</p> Signup and view all the answers

    What role does the sacrificial anode play in a cathodic protection system?

    <p>It corrodes sacrificially to protect the structure</p> Signup and view all the answers

    Why is a metallic connection installed between the sacrificial anode and the structure in a cathodic protection system?

    <p>To create a return current path for electrons</p> Signup and view all the answers

    In order for the sacrificial anode method to work, what two other conditions must exist besides the anode and cathode?

    <p>A return current path and an electrolyte</p> Signup and view all the answers

    What does Step 1 of designing an Impressed Current Cathodic Protection System involve?

    <p>Reviewing soil resistivity</p> Signup and view all the answers

    What is the primary purpose of Step 1 in the design process?

    <p>To determine the current requirement for the cathodic protection system</p> Signup and view all the answers

    Which step involves calculating the number of anodes needed to satisfy the manufacturer's current density limitations?

    <p>Step 4</p> Signup and view all the answers

    What variable represents the recommended maximum current density output in the equation given in Step 4?

    <p>I1</p> Signup and view all the answers

    In the equation given in Step 5, what does the variable 'n' represent?

    <p>The design life in years</p> Signup and view all the answers

    Which variable in the equation given in Step 6 represents the soil resistivity?

    <p>p</p> Signup and view all the answers

    According to Step 7, what determines the final number of anodes to be used in the design?

    <p>The highest number calculated from Steps 4, 5, and 6</p> Signup and view all the answers

    What is the first step in designing a galvanic cathodic protection system?

    <p>Review soil resistivity</p> Signup and view all the answers

    Which equation is used to calculate the anode groundbed resistance in an impressed current cathodic protection system design?

    <p>Ra = ρ / (2πr)</p> Signup and view all the answers

    What is the purpose of calculating the total circuit resistance in an impressed current cathodic protection system design?

    <p>To calculate the rectifier size needed</p> Signup and view all the answers

    Which step in the galvanic cathodic protection system design involves selecting the number of anodes to be used?

    <p>Step 6</p> Signup and view all the answers

    What is the purpose of calculating the groundbed header cable resistance in an impressed current cathodic protection system design?

    <p>To calculate the total circuit resistance</p> Signup and view all the answers

    Which step in the impressed current cathodic protection system design involves preparing plans and specifications?

    <p>Step 13</p> Signup and view all the answers

    What is the primary purpose of cathodic protection?

    <p>To control the corrosion of a metal surface by making it the cathode</p> Signup and view all the answers

    How does cathodic protection work to reduce corrosion?

    <p>By applying an external current to the metal to be protected</p> Signup and view all the answers

    What is the relationship between the electric current and the corrosion rate in a metal?

    <p>The higher the electric current, the greater the corrosion rate</p> Signup and view all the answers

    What is the key principle behind cathodic protection?

    <p>Reducing the difference in potential between the anode and cathode</p> Signup and view all the answers

    What is the primary way that cathodic protection is applied to a structure?

    <p>By applying a current to the structure from an outside source</p> Signup and view all the answers

    More Like This

    Corrosion Protection Methods
    30 questions
    Corrosion Control Methods
    15 questions
    Use Quizgecko on...
    Browser
    Browser