Page 173 - Challenges in Corrosion Costs Causes Consequences and Control(2015)

GAS DISTRIBUTION 151

Natural gas producing wells

Gathering pipelines
Transmission pipelines

Processing
plant

Compressor
stations

City gate

Underground Large volume
storage Meter customer

Distribution pipelines

Regulator
Figure 3.17 Components of a natural gas production, transmission, and distribution (7).

including pipe-to-soil potential and coating surveys. One difference is that in
distribution systems, leak detection is considered to be an acceptable method of
corrosion monitoring for the pipelines without CP.
For gas distribution piping, corrosion mitigation is primarily sacrificial CP. ILI is
not feasible for the relatively complex network of distribution mains and services.
This makes integrity assessment of the piping somewhat difficult.
Replacement costs of the infrastructure were calculated to obtain funding for cor-
rosion control in maintaining the existing metallic piping.

3.13.1 Pipe Failures
Low-pressure gas distribution pipeline failures result in leaks that undetected might
ignite and cause an explosion. The number of leaks because of corrosion was: mains