Unprotected pipelines corrode, no
matter where the pipeline is. If it’s buried underground, above ground or in
water, it’s going to deteriorate. As 60% of our nation’s transmission lines
approach their life expectancy of a half century, we’re hearing more and more
about pipeline failures. This should not be a surprise. Without implementing
safety measures and having a corrosion control program, corrosion makes
transporting hazardous material unsafe.
A successful corrosion control
program is a never ending practice. It begins with an effective design and
installation of the pipeline, executing corrosion control methods, and
maintaining and monitoring the lines. Here are some of the methods NACE (National Association of Corrosion
Engineers) recommends as part of a successful corrosion control
program to protect oil and gas pipelines. With the exception of the last
method, three of the four can be used on existing pipelines.
- Cathodic protection (CP) is a
method to control corrosion by using a direct electrical current which
neutralizes external corrosion typically associated with metal pipe. It is
generally used when a pipeline is buried underground or in water. When
executed on a new pipeline, cathodic protection can prevent corrosion from
the start. On an older pipeline, cathodic protection can impede existing
corrosion of the line.
- Coatings
and linings are applied to pipelines whether above or below
ground and often are used in combination with cathodic protection. Another
application that is currently getting some attention is the use of fiber-reinforced
polymers to strengthen and repair pipelines.
- Corrosion inhibitors are compounds
which when added to the upstream pipeline can inhibit the corrosion of
carbon and low-alloy steels which are commonly used because of their cost
effectiveness.
- Pipeline material used will also
significantly influence corrosion. Using materials like plastic, stainless
steel or special alloys can enhance the lifetime of the pipeline, while
steel or steel reinforced concrete is subject to corrosion.
While the nationwide corrosion
issue may seem a bit daunting, I thought it was a good time to discuss some
technology we currently have which can indefinitely extend the structural life
of our pipelines.
No comments:
Post a Comment