Both protection procedures and Integrity Management Programs are advancing on the transportation side of the pipeline industry. But distribution systems, “from city gate to burner tip,” are quite complex and not as well protected. Regulatory and operating dangers for owners and operators can be avoided, as EMS Group suggests in this article.

Attention: this article is addressed to the owners and managers of pipelines that distribute natural gas or liquids from the city gate to the burner tip.

Local distribution companies, for example, receive natural gas from transmission pipelines, distribute it to commercial and residential end-users, and earn revenue from it. Refineries and petrochemical plants operate their own distribution systems for both inputs and outputs.

Among other things, the Pipeline Inspection, Protection, Enforcement and Safety Act of 2006 extended the US Department of Transportation’s oversight to include gas and oil pipelines operating at low pressures.

In simple terms, this means you: the ones with the targets on your back. You’re operating in a world that’s different in complexity from transportation pipeline companies, and just as critical. Distribution pipelines are generally smaller in diameter than gas transmission pipelines and operate at reduced pressures. When the 6” pipeline goes through a 4” valve, then to a 3” pipeline, then into a 2” pipeline – that’s where transmission meets the neighborhood.

Two factors paint potential targets on you and your company. First, owners of distribution assets may not always be as cognizant of Federal, state and municipal regulations regarding pipeline safety, and the Integrity Management Programs (IMP) that regulators demand of them.

Owners may not perceive that regulatory demand affects them, or understand it thoroughly enough. This lack of awareness may arise from several sources. For instance, a new company and its investors may have purchased another refiner’s assets. It has purchased the revenue-producing potential of the distribution pipelines that provide feedstocks (in) and refined products (out). But at the same time, it has also “bought” liability, based on those same pipelines. The
new owner may not know about the increasing number and stringency of regulations, the investment required to meet those regulations, or the severe penalties they face if the regulations are not met.

In fact, the Federal government and its regulators are actively looking for you, and they step up their enforcement efforts every time there is a pipeline accident or incident. Maybe you are in this target group.

Second, if a distribution pipeline owner has to shut down its lines for any reason, productivity stops. Revenue stops. So if an unanticipated event occurs (and according to the demands of proper IMPs, there shouldn’t be), or the owner is forced by regulators to stop using his distribution system because of pipeline safety-related concerns, customers may
be left without resources. In this context, it becomes a competitive issue. If one distributor isn’t able to deliver, then another one will. Are you in this category?
In either case, the way to protect your distribution lines as well as yourself against regulatory or financial surprises lies in maintaining and proving an effective and continuous IMP. This is the only sure way to get the target off your back.

Conquering the Complex World of Distribution Protection and IMP
According to some sources, there are approximately 1.9 million miles of natural gas distribution pipelines in the US. As noted above, they are usually smaller in diameter than gas transmission pipelines and operate at reduced pressures. Distribution systems consist of mains that are normally installed underground, along or under streets and roadways; smaller service lines; even tank terminal operations. Some of these may be yours. So you not only protect them – you have to continually measure the effectiveness of that protection.

Because corrosion can dramatically reduce equipment reliability and cause premature failure of key capital assets, cathodic protection of distribution pipelines and tank terminal assets is well-established. It is a proven, effective defense, which leads (in turn) to continuous product delivery, revenue and profit. Cathodic protection systems are crucial to meeting some of your regulatory – and operating – requirements.

But you also have to be able to prove to regulators that you have an IMP for your assets, and that you are following this program absolutely.

Here’s where it gets tricky. Because distribution systems are composed of pipelines and other fixtures of mixed diameters, mechanical methods cannot prove your integrity program. You cannot pig multi-diameter pipe. You cannot take down the delivery pipeline for hydrostatic testing, because of full-time delivery demand.

To conquer this world fully – to get those targets off your back – you should also be applying testing methodologies such as External Corrosion Direct Assessment and Internal Corrosion Direct Assessment, specifically developed by NACE International, to maintain, manage and prove your integrity efforts.

The Value of NACE-Developed Testing Methods
These two distribution line testing methods are worth a quick review. External Corrosion Direct Assessment (ECDA) is a formal, non-mechanical process for improving safety by assessing and reducing the impact of external corrosion on pipeline integrity. It enhances the assessment of external corrosion by identifying and addressing corrosion activity. It helps you prevent external corrosion defects from growing to a size that are large enough to affect the structural integrity of your assets.

Internal Corrosion Direct Assessment (ICDA) has been developed to assess the corrosion impact of internal corrosion in gas transmission pipelines. Again, it is non-mechanical, and it also helps assure pipeline integrity. The method is applicable for gas transmission lines that normally carry dry gas but may suffer from short-term upsets of wet gas or liquid water (or other electrolytes).

Properly applied, these methodologies continually confirm the value of corrosion monitoring and the effectiveness of cathodic protection for buried distribution pipelines. Both methodologies offer a proactive advantage over non-applicable mechanical integrity assessment methodologies, such pressure testing and in-line inspection.

In addition to proven cathodic protection systems, we recommend following NACE specifications, backed by sound engineering principles, in three ECDA/ICDA-related methodologies:

1. Close internal survey
2. Direct current variance gradient surveys
3. Pipe current mapping.

This should be backed up with additional support activities which help distribution asset owners avoid both operating and regulatory problems:

• Implementing rigorous repair programs based on ECDA/ICDA line pipe inspection
• Developing management system procedures for regulatory compliance
• Integrating management of change (MOC), quality assurance, and root cause analysis procedures into daily practices.

Make Your Target – Don’t Be the Target
If asset owners and managers adopt these test procedures – if you combine effective cathodic protection with ECDA/ICDA methodologies – along with the resulting documentation, you are going to achieve two goals.

First, longer-term asset protection means you’re more likely to achieve your operating and revenue targets. Your “cash register” is protected because the product will continue to be delivered.

Second, rigorous, documented assurance that your IMP meets regulatory demands at all levels will advance public safety, underscore environmental protection and offer visible proof of pipeline reliability.

In the complex world of city gate-to-burner tip distribution systems, this is the certain way to make sure you make your target instead of being one.