Page 198 - Pipeline Rules of Thumb Handbook

8: Corrosion/Coatings

Hand-held computer determines concrete coating thickness.......... 186 How can the current output of magnesium rod used for the
NAPCA specifications......................................................................... 188 cathodic protection of heat exchanger shells be predicted? ........ 211
How much primer for a mile of pipe?............................................... 191 What spacing for test leads to measure current on a
How much coal-tar enamel for a mile of pipe? ................................ 192 pipeline? .......................................................................................... 211
How much wrapping for a mile of pipe? .......................................... 192 How many magnesium anodes are needed for supplementary
Estimating coating and wrapping materials required per mile protection to a short-circuited bare casing?.................................. 212
of pipe.............................................................................................. 192 Group installation of sacrificial anodes.............................................. 212
Coefficient of friction for pipe coating materials.............................. 193 How can the life of magnesium anodes be predicted? .................... 213
Trouble shooting cathodic protection systems: Magnesium anode How to find the voltage rating of a rectifier if it is to deliver a
system .............................................................................................. 195 given amount of current through a given ground bed
Cathodic protection for pipelines ...................................................... 196 (graphite or carbon)........................................................................ 213
Estimate the pounds of sacrificial anode material required for Determining current requirements for coated lines......................... 213
offshore pipelines............................................................................ 204 Determining current requirements for coated lines when
Comparison of other reference electrode potentials with that of pipe-to-soil potential values are estimated .................................... 213
copper-copper sulfate reference electrode at 25°C...................... 206 HVDC effects on pipelines ................................................................ 214
Chart aids in calculating ground bed resistance and rectifier Troubleshooting cathodic protection systems: Rectifier-ground
power cost ....................................................................................... 207 bed ................................................................................................... 218
How can output of magnesium anodes be predicted? ..................... 208 How to control corrosion at compressor stations.............................. 219
How to determine the efficiency of a cathodic protection Project leak growth ............................................................................. 220
rectifier............................................................................................. 208 Advances in Pipeline Protection...........................221
How to calculate the voltage drop in ground bed cable quickly ..... 209 Methods of locating coating defects .................................................. 222
What is the most economical size for a rectifier cable? ................... 209 Case histories....................................................................................... 225
How to estimate the number of magnesium anodes required Estimate the number of squares of tape for pipe coating
and their spacing for a bare line or for a corrosion (machine applied) ........................................................................... 226
“hot spot”......................................................................................... 210 Estimate the amount of primer required for tape............................ 227
How can resistivity of fresh water be determined from chemical Tape requirements for fittings............................................................ 227
analysis? ........................................................................................... 210
What will be the resistance to earth of a single graphite Induced AC Voltages on Pipelines May
anode?.............................................................................................. 211 Present a Serious Hazard..................................228
How to estimate the monthly power bill for a cathodic protection Measuring Unwanted Alternating Current
rectifier............................................................................................. 211
What will be the resistance to earth of a group of graphite anodes, in Pipe ................................................................230
in terms of the resistance of a single anode? ................................ 211 Minimizing shock hazards on pipelines near HVAC lines ............... 235

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