A key cause of pipe failure in steel pipelines is corrosion. Corrosion is the gradual destruction of metal by chemical and/or electrochemical reaction with the environment. Without proper corrosion protection, every steel pipe will eventually deteriorate and fail resulting in leaks.
Three methods are commonly used to reduce pipe corrosion:
- Cathodic protection (CP) is a system that uses direct electrical current to counteract the normal external corrosion that occurs on a metal pipeline due to soil and moisture conditions.
- Pipeline coatings and linings protect against corrosion by preventing the bare steel from coming in direct contact with corrosive environmental conditions.
- Corrosion inhibitors are substances that can be added to the gas running through a pipeline to decrease internal corrosion.
Higher-pressure pipes are commonly subjected to periodic inspection to detect corrosion since failure of a high-pressure pipeline is especially dangerous. The primary method of inspection is smart pigging with an internal device that takes various measurements that can be used to detect corrosion. In some cases monitoring devices are also used to detect corrosion.