Page 9 - Pipeline Rules of Thumb Handbook

P. 9

NAPCA speciﬁcations . . . . . . . . . . . . . . . . . . . . . . . . 188 HVDC effects on pipelines . . . . . . . . . . . . . . . . . . . . 214
How much primer for a mile of pipe? . . . . . . . . . . . . 191 Troubleshooting cathodic protection systems:
How much coal-tar enamel for a mile of pipe? . . . . . . 192 Rectiﬁer ground bed . . . . . . . . . . . . . . . . . . . . . . . 218
How much wrapping for a mile of pipe? . . . . . . . . . . 192 How to control corrosion at compressor stations . . . . . 219
Estimating coating and wrapping materials required Project leak growth . . . . . . . . . . . . . . . . . . . . . . . . . . 220
per mile of pipe . . . . . . . . . . . . . . . . . . . . . . . . . . . 192
Coefﬁcient of friction for pipe coating materials . . . . . 193 Advances in Pipeline Protection . . . . . . . . 221
Troubleshooting cathodic protection systems: Methods of locating coating defects . . . . . . . . . . . . . . 222
Magnesium anode system . . . . . . . . . . . . . . . . . . . 195 Case histories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
Cathodic protection for pipelines . . . . . . . . . . . . . . . . 196 Estimate the number of squares of tape for pipe
Estimate the pounds of sacriﬁcial anode material coating (machine applied) . . . . . . . . . . . . . . . . . . . 226
required for offshore pipelines . . . . . . . . . . . . . . . . 204 Estimate the amount of primer required for tape . . . . 227
Comparison of other reference electrode potentials Tape requirements for ﬁttings . . . . . . . . . . . . . . . . . . 227
with that of copper-copper sulfate reference
electrode at 25°C . . . . . . . . . . . . . . . . . . . . . . . . . 206 Induced AC Voltages on Pipelines May
Chart aids in calculating ground bed resistance and Present a Serious Hazard . . . . . . . . . . . . 228
rectiﬁer power cost . . . . . . . . . . . . . . . . . . . . . . . . 207
How can output of magnesium anodes be
predicted? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208 Measuring Unwanted Alternating
How to determine the efﬁciency of a cathodic Current in Pipe . . . . . . . . . . . . . . . . . . . . 230
protection rectiﬁer . . . . . . . . . . . . . . . . . . . . . . . . . 208 Minimizing shock hazards on pipelines near HVAC
How to calculate the voltage drop in ground bed lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235
cable quickly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
What is the most economical size for a rectiﬁer
cable? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
How to estimate the number of magnesium anodes 9: Gas—General, 237
required and their spacing for a bare line or for a Know the gas laws . . . . . . . . . . . . . . . . . . . . . . . . . . . 238
corrosion “hot spot” . . . . . . . . . . . . . . . . . . . . . . . . 210 Calculate gas properties from a gas analysis . . . . . . . . 240
How can resistivity of fresh water be determined Physical properties of selected hydrocarbons and
from chemical analysis? . . . . . . . . . . . . . . . . . . . . . 210 other chemicals and gases . . . . . . . . . . . . . . . . . . . 244
What will be the resistance to earth of a single Nomograph for calculating density and speciﬁc
graphite anode? . . . . . . . . . . . . . . . . . . . . . . . . . . . 211 volume of gases and vapors . . . . . . . . . . . . . . . . . . 252
How to estimate the monthly power bill for a cathodic
protection rectiﬁer . . . . . . . . . . . . . . . . . . . . . . . . . 211 Considerations for Selecting Energy
What will be the resistance to earth of a group of Measurement Equipment . . . . . . . . . . . . 253
graphite anodes, in terms of the resistance of a
single anode? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211 Facts about methane and its behavior . . . . . . . . . . . . 259
How can the current output of magnesium rod used Conversion table for pure methane . . . . . . . . . . . . . . 263
for the cathodic protection of heat exchanger shells Categories of natural gas and reserves terminology . . . 264
be predicted? . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211 Glossary of common gas industry terms . . . . . . . . . . . 265
What spacing for test leads to measure current on a
pipeline? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211
How many magnesium anodes are needed for 10: Gas—Compression, 268
supplementary protection to a short-circuited bare
casing? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212 Compressors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269
Group installation of sacriﬁcial anodes . . . . . . . . . . . . 212 Performance calculations for reciprocating
How can the life of magnesium anodes be compressors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
predicted? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 Estimating suction and discharge volume bottle sizes
How to ﬁnd the voltage rating of a rectiﬁer if it is to for pulsation control for reciprocating
deliver a given amount of current through a given compressors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272
ground bed (graphite or carbon) . . . . . . . . . . . . . . 213 Compression horsepower determination . . . . . . . . . . . 274
Determining current requirements for coated lines . . 213 Generalized compressibility factor . . . . . . . . . . . . . . . 276
Determining current requirements for coated lines Nomograph aids in diagnosing compressor cylinder
when pipe-to-soil potential values are estimated . . . 213 ills . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277

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