Gas Pipe Registry Provides Enhanced System Safety and Accountability
By Stephen C. Cooper
As growing demand for natural gas reaches an all-time high, the industry is responding with standardized methodology for tracking, which has begun through roll-out with manufacturers of polyethylene (PE) pipe and components, the primary material of choice being used currently in gas distribution systems. The efforts to normalize tracking are an outgrowth of the Pipeline and Hazardous Materials Safety Administration’s (PHMSA) final rule establishing integrity management requirements for gas distribution pipeline systems. Industry estimates show use of PE pipe at greater than 97 percent for new and replacement gas lines, the majority of which are up to 6-in. diameter, and with trending use of 8-in. and larger diameter lines growing in popularity.
According to the American Gas Association, (AGA), there are more than 66 million services and 2.4 million miles of gas distribution pipe in service. In 2012, the Plastics Pipe Institute (PPI), the major trade association representing all segments of the plastic pipe industry, took action to help address the overall industry need for accountability by establishing a manufacturers’ identification registry under license from Operations Technology Development (OTD) which can be found at www.ComponentID.org, a website that acts as a clearinghouse for the registration of all gas pipe and component manufacturers’ identification codes.
“This website provides a universal portal where manufacturers can easily inaugurate their efforts toward compliance by creating their own ID codes as the critical part of the tracking and traceability system,” said Tony Radoszewski, PPI’s executive director. “It was developed to jump start manufacturers implementation procedures for product traceability and it allows gas utilities a centralized location for identifying components used within any gas distribution system.
“PPI has agreed to operate and maintain this registry developed in coordination with the OTD consortium of gas utilities to support the registration of a unique manufacturer identifier in conjunction with the ASTM F2897-11 ‘Standard Specification for Tracking and Traceability Encoding System of Natural Gas Distribution Components (Pipe, Tubing, Valves and Fittings),’” he said.
ASTM F2897 alphanumeric and barcode marking requirements are now included in many leading plastic gas component standards including: ASTM D2513, F1924, F1948 and F2138.
“A lot of companies are working to figure out the best way to implement their Distribution Integrity Management Program, or DIMP,” offered Randy Knapp, director of engineering for PPI’s Energy Piping Systems and Building & Construction Divisions. “A big part of DIMP is product identification. Before, they had a difficult time tracking and tracing what products go into the ground, and where pipes and valves are located. That’s where the component ID comes into play … along with ASTM F2897 requirements it gives the industry a uniform way of marking products and applying bar codes that allow for immediate identification no matter what materials are involved in a system.
“This registry program is what utilities have been waiting for, so they’re enthused about it. Now, they have an immediate means for taking initial steps toward compliance. This tracking and tracing system can be used by any size manufacturer and a utility of any size. And for all pipe and components … it’s open for the entire system, not just PE pipe and component makers,” Knapp said.
Radoszewski echoed, “The PPI manufacturer’s identification service is available to all gas industry component manufacturers, and for all kinds of materials — anyone who wishes to take advantage of it and not only PPI members.”
He added that it is anticipated that other gas system components such as metallic piping and fittings will be added in the future. “We believe that with the successful implementation of this program into gas distribution, this type of tracking and traceability program could prove valuable for other applications such as potable water or storm water management systems,” Radoszewski said.
This is just the latest step in gas pipeline progress. There have also been ongoing improvements in the PE material itself and the pipe including the expanded use of PE 4710 grade of pipe. For example, since New Mexico Gas Co. (NMGC) completed its laboratory and field research study of PE 4710 resin, it specifies only plastic pipe made from this high-performance polyethylene resin. It has also added some 28,000 customers and installed more than 1,200 miles of pipe made from the state-of-the-art grade of polyethylene.
“The research and development teams of pipe and resin manufacturers continually work to produce new products such as PE 4710 that will benefit the industry,” Radoszewski said. “The commercialization of PE 4710 allows for the maximization of pipe performance in gas systems, bringing an excellent level of slow crack growth resistance and enabling a piping system to be operated at high pressure without sacrificing safety or service life. PE 4710 produces a very efficient pipe, which leads to savings in materials, transportation and installation.”
NMGC, based in Albuquerque, provides natural gas to more than 500,000 customers in 345 urban and rural communities throughout the state via 12,000 miles of pipeline, comprised of 1,600 miles of transmission pipe and close to 10,500 miles of distribution mains. Concurrent with advances in plastic material science, the company began to transition from the predominant use of steel pipe to PE pipe in the late 1970s and early 1980s. Today, approximately 57 percent of the pipelines maintained by the company are PE.
According to Angela Serrano de Rivera, manager of gas system engineering, the potential benefits of using advanced bimodal PE 4710 gas pipe first drew the attention of NMGC in 2005. Prior to that, unimodal PE 3408 pipe was successfully used for many years. Faced with limited pipe supply due to Hurricane Katrina and the challenge of delivering gas safely and cost-effectively under an extremely wide range of operating conditions, engineers at NMGC were intrigued by industry buzz indicating bimodal high density polyethylene (HDPE) resin’s excellent resistance to slow crack growth (SCG) and rapid crack propagation (RCP), critical criteria for any gas pipe material. These attributes lead to higher pressure capabilities while maintaining PE’s long service life expectancy and versatility of installation, which includes trenchless procedures.
Based on the positive results of their internal evaluation, NMGC began field installation of bimodal PE 4710 gas pipe in December 2005. To date, a total of 1,200 miles of PE 4710 pipe has been installed across New Mexico’s challenging terrain, in urban and rural locations, including 224,741 ft of replacement pipe in 2008 alone. The installed pipes range from ½-in. CTS to 6-in. IPS and 7 to 11 SDR.
Serrano de Rivera offered an overview of the study’s results, “After more than six years of impressive experience with PE 4710 pipe used in the extreme conditions of New Mexico without incident, New Mexico Gas Co. is pleased to report that bimodal pipe is proving to be an enduring solution and is the only plastic pipe approved to be used in New Mexico Gas Co.’s gas system.”
According to PPI’s Knapp, the focus for the gas industry continues to be replacement of aging gas lines. “This is going gangbusters right now,” he said. “The combination of horizontal directional drilling techniques and PE pipe is making it physically and financially possible to replace the old systems. The concentration is still cast iron replacement. Operators are required to know the specific characteristics of their system and operating environment to identify threats, evaluate the risk, and take measures to reduce the risk. Utilities know they have it in the ground and they have to have defined programs in place to say how they are going to replace it, when and how much, and the timetable. Many of these systems are approaching the end of their useful life so the utilities have to get them out of the ground, and that has been accelerating during the past year or two in particular.
“This is why the identification program is so timely,” Knapp said. “It’s been over a year since requirements have been in place for DIMP. And with more than 32,000 miles of cast iron still in the ground and to be replaced, it’s the perfect time to also add the bar code to each component.”
Based in New York, Stephen C. Cooper has been reporting on the gas and pipeline industries for several decades.