Category Archives: Close Interval Surveys

Linear Anodes for Hard-to-Reach Places [Rusty Talks]

Rusty and Josh Johnston chat about a recent project and case study involving the use of linear anodes for hard to reach places.


This month, MATCOR exhibited at the AMPP Central Area Conference held in Kansas City. MATCOR’s Mr. Josh Johnston, along with Mr. Chad Farris of Energy Transfer, jointly presented a paper—a case story using linear anodes as a shallow horizontal anode bed installed along two pipelines in central Kansas.

Rusty: Josh, tell us how it felt to finally be in a real-life conference interacting with people in person after the last year and half of cancelled conferences and virtual conferences.

Josh: It is always great to get to interact with our friends and industry colleagues, clients, suppliers and competitors to share information and discuss the challenges that our industry faces—especially given the events of the past couple of years. Presenting this paper was a great opportunity to highlight the use of linear anodes to protect hard to reach areas on older pipelines.

Rusty: Can you describe the problem that you covered in your presentation?

Josh: Energy Transfer had two older pipelines that were not meeting criteria in a rural location. As is typical in a lot of pipeline cathodic protection applications, the pipelines were being protected by impressed current anodes located at road crossings where power was readily available. The roads ran parallel to each other and were located one mile apart. The pipeline traversed these two roads and the area in between was mostly farmland. As a result of the age and coating condition, the shallow horizontal anode beds, located at the road crossings, were not able to project much more than a ¼ mile from each end, leaving approximately ½ mile in the center under protected. This was clearly identifiable in the close interval survey (CIS) data.Linear Anodes for Hard to Reach Places

Rusty: Couldn’t they simply increase the current output of the existing shallow ground beds at each end of the pipeline to drive more current to the center section in between?

Josh: They tried that approach, and it did not work, raising concerns that driving excessive current onto these older pipelines could actually make the situation worse by further disbanding any coating close to the existing ground beds.

Rusty: So where did MATCOR come into this project

Josh: MATCOR proposed linear anodes be installed parallel to each of the pipelines in the area between the two roads. MATCOR developed the very first MMO (mixed metal oxide) linear anodes over 30 years ago and we have the most experience designing linear anode CP systems.

Rusty: So it sounds easy, you take a couple of ½ mile segments of linear anode, trench them in parallel to pipeline and run a couple of long extension cord cables back to the road where there is power.

Josh: Well it does sound easy; however, in practice it is critical that any linear anode design carefully addresses voltage drop, and that the power feed cabling is configured so that each anode segment output is balanced. If this is not engineered properly, you could have a large disparity in the voltage being applied on one end of the anode segment relative to the other end. This would result in a very uneven distribution of current. Discussing the design considerations for the power feed cabling was the primary focus of this presentation.

Rusty: So how did it work out?

Josh: MATCOR was able to use some creative cabling analysis and routing to assure that the voltage difference from one end of an anode segment to the other was no more than a 10% variance. The post installation and commissioning CIS data delivered an outstanding current distribution.

Rusty: Thanks for providing a very quick overview of your presentation—any final thoughts or comments?

Josh: When designed properly, linear anodes can be a real problem-solving solution for older pipelines with current distribution and attenuation issues.

Oh yeah, Kansas City BBQ still rocks!

Have questions or need a quote for linear anodes or installations services? Contact us at the link below. For immediate assistance, please call +1-215-348-2974.

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Not Just a Walk Along the ROW: Close Interval Potential Surveys

Close Interval Potential Surveys (CIPS) or close interval surveys (CIS) for those in the United States, are an invaluable assessment tool used to maintain pipeline integrity. Close Interval Surveys are frequently mandated by pipeline regulatory authorities.

Keys to a Successful CIPS Survey

  • Selecting a qualified survey crew
  • Advanced planning
  • Selecting the appropriate CIPS Type
  • Accurate CIPS Data Collection
  • Expert Data Analysis and Reporting

Close Interval Surveys (CIS, CIPS)Learn more about the keys to a successful CIPS survey and other considerations in our recent article appearing in World Pipelines, “Not Just a Walk Along the ROW” by Ted Huck.

READ THE ARTICLE

Are you ready for spring close interval surveys?

MATCOR is here to help. Our experienced and NACE-trained crews are ready to perform close interval surveys to keep your pipeline cathodic protection systems in compliance and operating effectively.

  • Excellent safety record
  • Accurate, reliable data collection
  • Daily field progress reports
  • Extensive engineering and IT support

Contact MATCOR about your CIPS requirements or learn more about our close interval survey capabilities

 

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