PHMSA Standards Update Drives Plastic, Composite Pipe Innovation in Gas Infrastructure
Author: D. FINK and R. KNAPP, The Plastics Pipe Institute, Inc. (PPI), Irving, Texas
(P&GJ) — The U.S. gas-distribution and transmission industry is at a pivotal juncture. Regulatory bodies are modernizing pipeline safety standards to incorporate new materials and technologies. At the same time, manufacturers and operators are advancing plastic, composite and high-performance piping systems supported by data-driven safety initiatives. Together, these regulatory and technological shifts present opportunities to improve safety, reliability and performance across gas infrastructure. They also align with the U.S. Environmental Protection Agency’s (EPA) emerging FY 2026–2030 Strategic Plan, which emphasizes five strategic pillars guiding environmental protection and infrastructure development.
Regulatory developments
Recently PHMSA published their “Periodic Standards Update II” in the Federal Register. This update to 49 CFR Parts 191, 192 and 195 incorporates 19 updated industry technical standards and clarifies provisions to maintain alignment with the latest materials and construction practices. Its effective date is January 10, 2026. By recognizing modernized standards, PHMSA continues to promote the use of improved materials such as advanced polyethylene (PE), polyamide-12 (PA12) and reinforced composite piping systems (FIG. 1).
Across the U.S., state regulators are intensifying focus on legacy plastic piping systems, particularly older PE resins and early-generation materials like Aldyl A, due to their known performance limitations. Aldyl A, introduced in the 1960s, has been documented to exhibit lower resistance to slow crack growth, stress intensification and brittle-like cracking when compared to modern PE materials. Several incidents involving Aldyl A-related failures have underscored the need for accelerated identification and replacement of these materials.
States are implementing a range of measures to mitigate risks from legacy materials. Regulators are directing utilities to identify high-risk segments—particularly those located in densely populated or high-consequence areas (HCAs), and many states now require or incentivize replacement of older materials through safety improvement programs or enhanced leak monitoring. State regulators align with PHMSA’s Gas Distribution Integrity Management Program (DIMP), which designates some vintage materials as a material of concern requiring risk evaluation.
Regulatory updates influence how the industry designs and manages their systems. Updated American Society for Testing and Materials (ASTM) and American Petroleum Institute (API) standards support high-performance materials like PE4710, PA12 and composites. In order to reduce legacy risk, older materials (e.g., Aldyl A and PE3306) are now prioritized for replacement. PHMSA’s DIMP and the Pesticide Program Dialogue Committee (PPDC) databases help operators identify trends and mitigate risks proactively.
Innovations in plastic piping technology
The plastic piping industry continues to evolve through advances in material science, manufacturing technology and data analytics. PE is well proven and has served the gas distribution industry for decades. Emerging materials such as PA12 and reinforced composite pipe (RCP) are expanding performance capabilities, while enhanced training and data tools are helping reduce installation-related failures.
Manufacturers are developing next-generation thermoplastics that exceed the performance of traditional PE systems in terms of pressure and temperature. PA12 offers exceptional strength, temperature tolerance and low gas permeation. It is approved by PHMSA for use up to 250 psi, making it suitable for intermediate-pressure distribution and certain transmission laterals. Its resilience and chemical resistance also make it ideal for hydrogen blending applications. Enhanced PE resins, like bimodal PE4710, improve resistance to slow crack growth and oxidation, extending service life.
Reinforced thermoplastic pipe (RTP) and composite systems combine a thermoplastic liner, a reinforcing layer (fiberglass, aramid or steel mesh), and an outer protective jacket. These designs can operate at pressures up to 3,000 psi, bridging the gap between plastic and steel. Their corrosion resistance, light weight and ease of installation make them attractive for high-pressure and gathering applications. PHMSA and standards organizations are expanding regulatory acceptance of composites under 49 CFR 192 Subpart B.
Enhanced installation and data use
Advancements in fusion technologies, trenchless construction and operator qualification programs have reduced failure rates linked to human error. PPDC data indicates that about 40% of early-life failures stem from installation issues, underscoring the need for rigorous training and oversight.
The PPDC—a collaboration among American Gas Association (AGA), American Public Gas Association (APGA) and PPI—tracks and records failures. Insights gained from this data help operators understand material trends, prioritize replacements and integrate lessons into DIMP and pipeline safety management system (PSMS) programs.
Integration with EPA Strategic Plan 2026–2030
The EPA’s forthcoming FY 2026–2030 Strategic Plan outlines five key pillars:
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Clean air, land and water for every American
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Restore American energy dominance
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Permitting reform and cooperative federalism
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AI capabilities
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Protecting and bringing back American jobs.
Gas infrastructure modernization aligns closely with these pillars. Plastic and composite pipe reduce methane emissions, protect groundwater and support clean air and land objectives. Efficient installations and durable materials enhance energy security, while advanced data and AI tools for failure prediction mirror EPA’s technology initiatives. Moreover, renewed manufacturing of PA12, composite systems and fittings supports domestic job growth.
Sustainability, resilience and lower carbon footprint of plastic piping in gas applications
Plastic piping systems are increasingly recognized for their contributions to sustainability, resilience and the reduction of greenhouse gas (GHG) emissions in gas distribution and transmission. Here’s how these systems support a lower carbon footprint and greater environmental stewardship:
1. Lower carbon footprint
Manufacturing efficiency: Modern plastic piping materials such as PE4710, PA12 and reinforced composite pipes require less energy to manufacture compared to traditional steel or iron pipes. This results in lower embodied carbon per unit length of pipe.
Reduced transportation emissions: Plastic pipes are lightweight, allowing for more efficient transportation and handling, which reduces fuel consumption and associated emissions during delivery and installation.
Methane emissions reduction: Plastic and composite pipes offer superior joint integrity and corrosion resistance, significantly reducing methane leaks—a potent GHG—compared to legacy metallic systems. This directly supports EPA’s clean air objectives and climate action goals.
2. Enhanced resilience
Corrosion resistance: Unlike steel, plastic piping does not corrode, which extends service life and reduces the frequency of repairs and replacements. This resilience is especially valuable in harsh or variable soil conditions.
Adaptability to new energy sources: Materials like PA12 are chemically resistant and suitable for hydrogen blending, supporting the transition to low-carbon fuels and future-proofing gas infrastructure.
Performance in extreme conditions: Reinforced thermoplastic and composite pipes can withstand high pressures and temperature fluctuations, making them suitable for a wide range of applications and environmental conditions.
3. Sustainability in practice
Efficient installation: Trenchless construction methods and fusion technologies minimize ground disturbance, reduce waste and lower the carbon footprint of installation projects.
Lifecycle benefits: The durability and long service life of modern plastic piping reduce the need for frequent replacements, conserving resources and minimizing environmental impact over decades of operation.
Alignment with strategic goals: The adoption of advanced plastic piping aligns with the EPA’s FY 2026–2030 Strategic Plan pillars, including clean air and water, energy security and job creation in domestic manufacturing.
Challenges and considerations
Despite progress, challenges remain. Asset records for older systems often lack manufacturer or installation data and replacing older materials like Aldyl A and PE3306 remains resource-intensive. Continued investment in fusion, joining and inspection training will be vital to help operators navigate varying state and federal requirements.
The convergence of regulatory modernization, material innovation and alignment with the EPA’s strategic vision marks a transformative era for the gas industry. By embracing PA12, composites and advanced analytics, operators can not only meet compliance standards but also lead in environmental stewardship, energy efficiency and public confidence. This is a defining opportunity for the gas sector to innovate while contributing to national goals for cleaner, safer and more resilient infrastructure.
Through the technical divisions and standards initiatives, the authors’ trade association plays a central role in shaping codes, supporting regulatory adoption and providing the technical foundation for modern gas infrastructure. The organization sets policies and methods for long-term performance metrics such as hydrostatic design basis (HDB) and pressure design basis (PDB) for thermoplastic materials used in gas piping applications.
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a PPI’s Hydrostatic Stress Board
About the authors
DAVID M. FINK is the President of PPI. PPI is the major North American, non-profit trade association representing the plastic pipe industry.
RANDY KNAPP Ph.D. is the Engineering Director for PPI’s energy piping systems division. PPI is the major North American, non-profit trade association representing the plastic pipe industry.