Review of Pressure Pipeline Standards and Material Usage - Taking ASME B31.8 and AS/NZS 2885 as Examples

I. Introduction

As the core infrastructure for energy transportation and industrial operations, pressure pipelines' safety and reliability directly relate to public safety, environmental protection, and the stability of energy supply. Globally, multiple mature pressure pipeline standard systems have been established. Among them, the Gas Transmission and Distribution Piping Systems (ASME B31.8) formulated by the American Society of Mechanical Engineers (ASME) and the Series on Pipelines for High-Pressure Fluids (AS/NZS 2885) published by Standards Australia are the most representative. The former focuses on comprehensive regulations throughout the entire gas transmission chain, while the latter forms a "single yet sufficient" technical safeguard system for high-pressure pipelines. Both standards share common principles in terms of standard frameworks, material selection, and practical applications, yet they also exhibit significant differences due to regional requirements. This article provides a systematic analysis of the core contents and material usage specifications of these two standards by combining standard texts and industry practices.

II. ASME B31.8: Comprehensive Regulations for Gas Transmission Pipelines

(A) Standard Positioning and Scope of Application

Since ASME initiated the development of pipeline safety standards in 1922, the B31 series has evolved into a pipeline regulation system covering multiple fields. Among them, B31.8, as a specialized standard for gas transmission, applies to all links throughout the gas industry chain, including gas pipelines, compressor stations, metering and pressure-regulating stations, main pipelines, and service pipelines up to the outlet of customer meters. Its jurisdiction further extends to offshore gas transmission and gathering pipelines, pipeline-type gas storage facilities, and storage pipelines, achieving full-chain coverage from the production end to the consumer end.

The core value of this standard lies in providing a comprehensive "materials - design - manufacturing - installation - testing - inspection" solution. As a supporting document of the B31 series, it, together with other pipeline regulations, constitutes the industry's foundational reference system. The applicable objects encompass manufacturers, construction parties, designers, operation and maintenance personnel, and regulatory authorities, forming a multi-party collaborative standard implementation mechanism.

(B) Core Technical Contents and Revision Trends

The latest revised version of ASME B31.8 presents three major technological upgrades: First, a new chapter on operator training and qualification certification has been added to strengthen "human factor safety" management, requiring relevant personnel to possess professional knowledge in pipeline integrity and material characteristics. Second, a dedicated chapter on damage prevention plans has been introduced to formulate systematic prevention and control measures against risks such as third-party damage and geological hazards. Third, the design formulas for plastic pipelines have been comprehensively revised to optimize the application parameters of non-metallic materials in gas transmission.

In terms of material specifications, the standard explicitly requires the selection of appropriate materials based on pipeline diameter, operating pressure, expected lifespan, and environmental conditions. Steel pipes and stainless steel pipes are the mainstream metallic materials selected, while quantitative indicators are proposed for the strength, toughness, and corrosion resistance of plastic pipelines. Wall thickness calculations must strictly adhere to standard formulas, taking into comprehensive consideration factors such as working pressure, material strength, temperature effects, and external loads. The quality control of welded joints must comply with the specific requirements of ASME welding standards. In addition, the standard mandates that pipelines must adopt anti-corrosion measures such as external coatings and cathodic protection to extend service life and reduce leakage risks.

(C) Standard Implementation and Industry Value

The practical value of ASME B31.8 is reflected in both regulatory compliance and efficiency improvement: On the one hand, strict adherence to the standard can help users meet the legal and regulatory requirements within their jurisdictions. On the other hand, by adopting industry best practices outlined in the standard, operational efficiency can be enhanced, costs optimized, and safety guaranteed simultaneously. The authority of this standard benefits from the technical support of professional committees. For example, Michael J. Rosenfeld, a current member of the ASME B31.8 Subcommittee, with over forty years of experience in pipeline materials, integrity, and standard development, has provided profound technical expertise for standard revisions.

III. AS/NZS 2885: Risk Management and Material Innovation in High-Pressure Pipelines

(A) Standard Origin and System Composition

The emergence of the AS/NZS 2885 series standards stems from Australia's unique energy transportation needs: Given the long distances between energy production sites and load centers, as well as the sparse population distribution, traditional European and American pipeline design models struggle to balance costs and efficiency. Consequently, the industry gradually developed a technical path of "high-strength steel + thin-wall design + high-pressure operation" in the 1970s and 1980s, leading to the creation of a dedicated standard system. Since its first release in 1987, this standard has evolved into a comprehensive system consisting of seven parts:

• AS 2885.0: General Requirements (Core Principles and Foundational Framework)

• AS/NZS 2885.1: Design and Construction (Key Aspects such as Material Selection and Structural Design)

• AS/NZS 2885.2: Welding (Specialized Specifications for Joint Quality Control)

• AS 2885.3: Operation and Maintenance (Requirements for Full Lifecycle Management)

• AS/NZS 2885.4: Subsea Pipeline Systems (Provisions for Special Environmental Adaptation)

• AS 2885.5: On-Site Pressure Testing (Verification Methods and Acceptance Criteria)

• AS/NZS 2885.6: Pipeline Safety Management (Risk Management and Threat Control)

The standard is regularly reviewed by the ME-038 Technical Committee, whose members include representatives from the industry, professional associations, and regulatory authorities of various states. It also coordinates the management of supporting standards such as AS 4822 (Coatings for Steel Pipeline Joints) and AS/NZS 1518 (High-Density Polyethylene Coatings), forming a technical synergy mechanism.

(B) Core Specifications and Technical Characteristics of Material Selection

1. Regional Adaptability in Material Selection

To achieve the goal of "reducing capital costs and improving transmission efficiency," AS/NZS 2885 explicitly requires the use of higher-strength pipeline steels. By enhancing material performance, the wall thickness can be reduced, and when combined with high-pressure operating parameters of 15.3 megapascals (more than double the earlier levels), the gas transmission volume per unit of steel is significantly increased. The standard primarily covers carbon-manganese steel pipeline systems, optimizing material property indicators for the transmission of single-phase and multiphase hydrocarbon fluids. Additionally, through supporting standards like AS 4822, it regulates the selection of coating materials, such as the application requirements for fusion-bonded epoxy (FBE) and high-density polyethylene (HDPE) coatings, balancing anti-corrosion performance and construction feasibility.

2. Full Lifecycle Perspective on Material Management

The standard integrates material quality control into the risk management system, requiring license holders to assess the material's resistance to various threats, including geological loads, third-party damage, and medium corrosion, during the design phase. Taking wall thickness determination as an example, unlike traditional standards that mandate分级 (classification) based on population density, AS/NZS 2885 requires separate wall thickness calculations for each pipeline segment based on factors such as puncture resistance and pressure conditions, along with written proof that pipelines in densely populated areas are free from rupture risks. Material approval necessitates a strict written procedure, with qualified personnel or entities signing off on key documents such as material selection and inspection reports to ensure traceability.

3. Forward-Looking Layout for Future Material Needs

The new name "Pipeline Systems - High-Pressure Fluids," effective in 2025, signifies the standard's expansion of material specifications to encompass the transportation of non-hydrocarbon fluids. In response to new media such as hydrogen and carbon dioxide, the standard is revising material compatibility requirements. Simultaneously, considering the demands for abrasion resistance and corrosion resistance of special fluids like mining slurries, it is promoting the adaptation of material standards to new energy transmission scenarios.

(C) Material Application Logic Driven by Risk Management

The core innovation of AS/NZS 2885 lies in the deep integration of material properties and risk management, requiring the identification of material-related threats through Safety Management Studies (SMS) and the implementation of risk control through design solutions, physical measures, and procedural methods. For instance, to address corrosion failure risks, it is necessary to simultaneously select corrosion-resistant materials (physical measures), implement coating protection (design solutions), and establish regular inspection systems (procedural methods) to reduce risks to the "As Low As Reasonably Practicable" (ALARP) level. This multi-dimensional control model is reflected in the material selection process as a closed-loop system of "performance verification + process control + continuous assessment": Materials must undergo performance verifications such as strength tests and corrosion tests before entering the site, welding quality must be supervised on-site during construction, and material degradation must be dynamically assessed based on pipeline inspection data during the operational phase.

IV. Core Differences and Material Specification Comparisons between the Two Standards

(A) Standard Positioning and Scope of Application

ASME B31.8 focuses exclusively on gas transmission, covering all pressure levels from low-pressure gas distribution pipelines to high-pressure transmission pipelines, and includes integrated regulations for station equipment and service pipelines. In contrast, AS/NZS 2885 focuses on high-pressure transmission pipelines with pressures greater than 1050 kilopascals, explicitly excluding station pipelines (which require the adoption of standards such as AS 4041 or B31.3). Moreover, after 2025, it will extend to the transmission of non-hydrocarbon fluids. These differences stem from regional needs: The United States has a high-density gas transmission network with complex scenarios, while Australia primarily features long-distance high-pressure trunk lines, necessitating targeted optimization of materials and pressure parameters.

(B) Technical Paths for Material Management

In terms of material selection logic, ASME B31.8 adopts a "working condition matching + formula calculation" model, directly guiding material selection through explicit wall thickness formulas and material strength grades. For example, the revision of plastic pipeline design formulas further refines the application scenarios of non-metallic materials. In contrast, AS/NZS 2885 is based on a "risk-driven + customized design" approach, allowing material specifications to be adjusted according to the specific threats of each pipeline segment, but requiring strict justification and approval procedures. Regarding corrosion protection, both standards require a combination of coatings and cathodic protection, but AS/NZS 2885 establishes more detailed technical indicators for coating materials through supporting standards like AS 4822.

(C) Responsible Parties and Implementation Guarantees

ASME B31.8 emphasizes collaborative implementation among multiple parties, with applicable objects covering all entities in the entire industry chain, but it does not specify a single responsible party. In contrast, AS/NZS 2885 assigns the decision-making responsibilities for material selection and quality control to the pipeline license holder, requiring them to assume written responsibility for major material-related decisions, while regulatory authorities are only responsible for process supervision. This division of responsibilities grants the Australian standard greater flexibility in the innovative application of materials, enabling it to quickly adapt to the application needs of new materials such as high-strength steel.

V. Conclusion

ASME B31.8 and AS/NZS 2885 have established two typical paradigms for pressure pipeline standards: The former ensures gas transmission safety through "comprehensive standardization," with material specifications emphasizing generality and operability; the latter achieves a cost-safety balance in high-pressure pipelines with "risk management as the core," and its material selection reflects distinct regional adaptability and an innovation-oriented approach. Both standards demonstrate that the rational selection of pressure pipeline materials not only needs to meet basic performance requirements such as strength and corrosion resistance but also must be deeply integrated with the standard framework, operational scenarios, and risk prevention and control systems.

With the growing demand for new energy transmission, the upgrade of plastic pipeline specifications in ASME B31.8 and the revision of AS/NZS 2885 for non-hydrocarbon fluid adaptation indicate that pressure pipeline material standards are evolving towards "multi-media compatibility and full lifecycle management." For industry practitioners, a deep understanding of the material logic of different standards and their precise application based on project scenarios is the key path to achieving a unified goal of pipeline safety and efficiency.

References

1. ASME, https://www.asme.org/codes-standards/find-codes-standards/b31-8-gas-transmission-distribution-piping-systems

2. APGA, https://apga.org.au/2885-standard-high-pressure-pipeline-systems