NACE CP2 Quiz 3 Questions and Answers (Verified Answers)

NACE CP2 Quiz 3 Questions and Answers (Verified Answers) A mitigation control bond should be designed to 1. carry the necessary current 2. restrict the current to that required to mitigate the problem 3. keep the current going in one direction if necessary 4. return the potential on the interfered with structure to its pre-interference state All of the above A mitigation bond may cause more problems under which of the following conditions? 1. Where the interfering structure bond point is more electropositive than the interfered with structure 2. Where the interfering structure bond point is more more electronegative than the interfered with structure 3. Where there are more than one, or changing, current discharge points 4. Where the interfering structure bond point potential varies from being more electronegative to more electropositive than the interfered with structure 1, 3 and 4 1. Where the interfering structure bond point is more electropositive than the interfered with structure 3. Where there are more than one, or changing, current discharge points 4. Where the interfering structure bond point potential varies from being more electronegative to more electropositive than the interfered with structure AC voltages on pipelines do NOT result from A. resistive (conductive) coupling B. electrostatic (capacitive) coupling C. electromagnetic induction coupling D. thermodynamic coupling D. Thermodynamic coupling On a cathodically protected pipeline, AC corrosion can be expected at which current densities? 1. 30 mA/m2 2. 10 A/m2 3. 110 A/m2 4. 200 A/m2 3 and 4 A close interval potential survey is a test where structure-to-electrolyte potentials are measured A. at 1 to 5 meter spacing along a pipeline B. at 1 to 3 kilometer spacing along a pipeline C. at the quarter points around a large tank D. close to the DC power source A. At 1 to 5 meter spacing along pipeline The AC voltage-to-ground on a section of pipeline paralleling AND crossing a power line tends to be highest 1. where the power line and pipeline cross 2. point where the power line and pipeline separate 3. at the ends of the pipeline 4. evenly along the pipeline 1, 2 and 3 1. where the power line and pipeline cross 2. point where the power line and pipeline separate 3. at the ends of the pipeline Methods of lowering hazardous AC voltages includes installing which of the following? 1. Grounds at the discontinuities between power line and pipeline 2. A bond to the steel power line tower 3. A gradient mat or a grid around aboveground structures 4. A remote ground away from the parallel section 1 and 3 1. Grounds at the discontinuities between power line and pipeline 3. A gradient mat or a grid around aboveground structures A polarization cell is used to A. polarize the pipeline B. polarize the electrical ground C. provide DC coupling but block AC D. provide AC coupling but block DC D. provide AC coupling but block DC Tests for interference can be indicated by which of the following? 1. Structure-to-electrolyte potential changes 2. Changes in line current magnitude or direction 3. Localized pitting in areas near or immediately adjacent to a foreign structure 4. Breakdown of protective coatings in a localized area All of the above When AC voltage of 13 VAC is measured on a pipeline, what course of action should be taken? 1. Wait until next year and take an AC voltage to confirm it has not changed 2. Contact the power company to determine what percent of load the power line is operating 3. Advise other personnel that a near hazardous situation exists on the pipeline 4. Advise the owner or supervisor that an AC mitigation programs should be investigated 2, 3 and 4 2. Contact the power company to determine what percent of load the power line is operating 3. Advise other personnel that a near hazardous situation exists on the pipeline 4. Advise the owner or supervisor that an AC mitigation programs should be investigated