Q&A About "Standards & Specifications"

Within the critical API 5L standard for line pipe, one of the most important and frequently asked questions revolves around the distinction between PSL1 and PSL2. From our perspective as industry specialists, this is more than a technical detail; it’s a fundamental decision that directly impacts a pipeline’s safety, performance, and long-term integrity.

Our goal is to clarify this distinction, helping engineers, project managers, and procurement teams specify the correct product with absolute confidence.

What Does PSL Mean?

PSL stands for Product Specification Level. The American Petroleum Institute (API) created these two distinct levels to provide clear tiers of technical and quality requirements for line pipe used in the oil and gas industry.

• PSL1: Represents the standard quality level for line pipe.
• PSL2: Represents a higher quality level with significantly more stringent requirements for testing, chemical composition, and mechanical properties.

The Key Differences: A Deeper Dive

While both levels must meet the baseline requirements of API 5L, PSL2 introduces a series of stricter controls. Let’s examine the most critical differences.

1. Chemical Composition

From a metallurgical standpoint, the tighter chemical controls for PSL2 are fundamental.

• PSL2 has stricter maximum limits on key elements like carbon, phosphorus, and sulfur. It also mandates a maximum Carbon Equivalent (CEQ), which is crucial for ensuring good weldability.
• PSL1 has more relaxed chemical limits.

Why it matters: The cleaner, more tightly controlled steel required for PSL2 results in a pipe that is tougher, more weldable, and better suited for demanding service conditions, especially sour service (H₂S).

2. Mechanical Properties

This is arguably the most significant area of differentiation.

• PSL2 has mandatory minimum requirements for fracture toughness (measured by the Charpy impact test). It also has a maximum limit on the yield to tensile strength ratio.
• PSL1 has no mandatory toughness requirements (unless specified as an additional requirement by the purchaser).

Why it matters: Toughness is a material’s ability to resist the propagation of a fracture. For any pipeline where this is a significant risk—such as high-pressure gas lines or those in low-temperature environments—the mandatory toughness of PSL2 is non-negotiable for ensuring safety.

3. Manufacturing Process and Traceability

• PSL2 prohibits certain practices, such as the repair of the pipe body, which may be permissible under PSL1.
• PSL2 also requires full traceability, meaning each pipe can be traced back to the specific heat of steel from which it was made. PSL1 only requires traceability until all tests are passed.

Summary Table: PSL1 vs. PSL2 at a Glance

The Allland Steel Recommendation: How to Choose

A useful rule of thumb is to consider the consequence of failure.

• Choose PSL1 for: Standard, less critical applications. This includes pipelines where operating pressures and environmental risks are moderate. It is a reliable and more economical choice for a wide range of general uses.
• Choose PSL2 for: Mission-critical applications where safety and reliability are the highest priorities. This is the required standard for:
  • High-pressure gas transmission lines
  • Offshore pipelines
  • Pipelines in environmentally sensitive or low-temperature areas
  • Sour service (H₂S) applications

The additional upfront cost for a PSL2-compliant pipe is a sound investment in long-term asset integrity and risk mitigation.

Our Commitment to Compliance

Navigating technical standards can be complex, but our team is here to assist. Allland Steel has the proven expertise and advanced manufacturing capabilities to produce LSAW and SSAW pipes that fully comply with both PSL1 and PSL2 requirements of the latest API 5L edition.

For detailed technical specifications, please visit our API 5L Standards Page.

Or Contact a Specialist at Allland Steel to ensure the pipe you order meets the precise demands of your project.

While the 3LPE coating system is well-known for its superior pipeline protection, the quality of its application is not a matter of guesswork. It is governed by rigorous international standards, and among the most respected and frequently specified is DIN 30670.

For our clients, understanding this standard is key to appreciating the level of quality, durability, and long-term reliability you receive when you specify a compliant coating. It is the benchmark that separates a standard coating from a high-performance, long-life asset protection system.

What is DIN 30670?

DIN 30670 is a technical standard issued by the DIN (Deutsches Institut für Normung), the German Institute for Standardization. It specifically outlines the requirements for factory-applied, three-layer extruded polyethylene (3LPE) coatings on steel pipes and fittings for corrosion protection.

Although German in origin, DIN 30670’s comprehensive and stringent requirements have led to its adoption as a global benchmark for quality by pipeline owners, engineers, and manufacturers worldwide.

Key Quality Parameters Regulated by DIN 30670

A commitment to the DIN 30670 standard means a commitment to verifiable performance. Here are the critical quality parameters that the standard regulates, and why they matter for your project.

1. Coating Thickness

The standard mandates a minimum thickness for the outer polyethylene layer, which varies based on the pipe’s diameter.

• Why it matters: From an asset protection standpoint, sufficient thickness is the first line of defense against physical damage. This ensures the pipe is robust enough to withstand the rigors of transportation, on-site handling, and the stresses of backfilling during installation.

2. Peel Resistance / Adhesion

This crucial test measures the force required to peel the coating from the steel substrate at specific angles and temperatures.

• Why it matters: This is a direct measure of the coating’s bond strength. Excellent adhesion across all three layers is fundamental to the system’s performance. It prevents moisture from creeping under the coating and causing corrosion. A high peel resistance value is a hallmark of a properly applied, high-integrity coating.

3. Impact Resistance

This test assesses the coating’s toughness by dropping a specified weight from a set height onto the coated pipe. Afterwards, the impact area is tested for any “holidays” (pinholes or cracks).

• Why it matters: This simulates the real-world impacts a pipe might endure during its journey from the factory to the trench. A passing result demonstrates that the coating is tough and resilient, not brittle.

4. Cathodic Disbondment

This is one of the most critical long-term performance tests. It measures the coating’s ability to resist “unsticking” from the pipe surface in the presence of an electrical current from a cathodic protection system, especially at a point of minor damage.

• Why it matters: A low cathodic disbondment value is essential for the long-term health of the pipeline. It ensures that if a small holiday does occur, the corrosion will be contained to that tiny area and will not spread underneath the coating.

The Allland Steel Commitment to Quality

Compliance with demanding standards is at the core of our manufacturing philosophy. The 3LPE coatings applied at Allland Steel are engineered and rigorously tested to meet or exceed the stringent requirements set forth in DIN 30670.

When you specify a 3LPE coating from Allland Steel, you are not just ordering a product; you are investing in a protection system that is verified against one of the world’s most trusted benchmarks for quality and long-term performance. This commitment provides our clients with peace of mind and confidence in the longevity of their critical assets.

To discuss the specific coating requirements for your next project, contact our technical specialists at Allland Steel.

In the world of carbon steel pipe, ASTM A53, ASTM A106, and API 5L are three of the most dominant standards. A common point of confusion we address for our clients is understanding their distinct purposes. While these pipes may appear similar, they are engineered for very different applications, and selecting the correct standard is a critical step in ensuring a project’s safety, compliance, and cost-effectiveness.

Our goal is to clarify the key differences between these specifications, so you can confidently choose the right material for your specific application.

The Core Purpose of Each Standard

The easiest way to understand the difference is to start with the primary application each standard was designed to serve.

• ASTM A53: This is the general-purpose “workhorse” standard for pipe. It’s primarily intended for mechanical and pressure applications, as well as ordinary uses in steam, water, gas, and air lines. Think of it as the standard for general plumbing and structural applications.
• ASTM A106: This is the high-temperature specialist. The standard is written exclusively for seamless carbon steel pipe intended for high-temperature and high-pressure service. This is the required choice for applications like power plant piping, boilers, and refineries.
• API 5L: This is the pipeline professional’s standard. It is specifically written for the oil and gas industry to govern pipe used for conveying hydrocarbons (oil, gas) and water in pipeline transportation systems.

Key Technical Differences Explained

The different purposes of these standards lead to crucial differences in their technical requirements.

1. Manufacturing Method

This is one of the most fundamental distinctions.

• ASTM A53: Can be either seamless or welded (typically ERW – Electric Resistance Welded).
• ASTM A106: Is exclusively seamless. This is a non-negotiable requirement for its intended high-temperature service, as it eliminates the weld seam as a potential point of weakness under thermal stress.
• API 5L: Can be seamless or welded (ERW, LSAW, SSAW), covering the broad range of manufacturing methods used in the pipeline industry.

2. Chemical Composition

From a materials perspective, the chemical makeup is tailored for the application.

• ASTM A106: Deliberately includes silicon (min 0.10%), which enhances its performance and strength in high-temperature environments. It also has stricter controls on elements like sulfur and phosphorus than A53.
• ASTM A53: Has more general chemical requirements.
• API 5L: Has a detailed progression of chemical requirements that become stricter with higher grades (e.g., X42, X52, X70) to ensure weldability and toughness. PSL2 specifications have particularly strict chemical controls.

3. Mechanical Properties

The strength and toughness requirements are directly linked to the intended service.

• API 5L: Offers a much wider range of strength grades (up to X80 and beyond) and places a strong emphasis on fracture toughness, which is mandatory for the PSL2 specification. This is critical for ensuring the integrity of long-distance pipelines.
• ASTM A106 & A53: Are offered in a few common grades (e.g., Grade A, B, C) with standard strength requirements and typically no mandatory toughness testing unless specified by the customer.

Summary Table: A53 vs. A106 vs. API 5L at a Glance

The Allland Steel Guidance: Making the Correct Selection

A common and dangerous mistake is to assume these standards are interchangeable. Our role as your technical partner is to ensure you receive a product that is not only certified to a standard but is the correct standard for your application.

Here is a simple decision guide:

• Is your application general purpose, such as low-pressure water, air lines, or structural supports? ASTM A53 is the correct and most economical choice.
• Is your application for high-temperature service (e.g., steam lines, process piping) and must be seamless? ASTM A106 is the mandatory and only appropriate choice.
• Are you transporting oil, gas, or water in a pipeline? API 5L is the required industry standard. Your next step will be to select the appropriate grade and PSL level.

Navigating the nuances of steel pipe standards is our expertise. The technical team at Allland Steel is available to review your project specifications and ensure your material is optimized for performance, safety, and compliance.

Contact a technical specialist at Allland Steel to discuss your project requirements.

Every great structure is built on a solid foundation. In modern civil engineering, steel pipe piles are a cornerstone of that foundation, and the standard that governs their quality and performance is ASTM A252.

A frequent point of clarification we provide for our clients in the construction and geotechnical sectors is why this specific standard is so critical. The reason is simple: pipe manufactured to the A252 standard isn’t just a hollow steel section; it’s a structural element specifically engineered to bear immense loads and ensure the stability of buildings, bridges, and marine structures for generations.

What Exactly is ASTM A252?

ASTM A252 is the official designation for the American Society for Testing and Materials’ standard specification covering welded and seamless steel pipe piles.

Its scope is very specific. It covers steel pipe that is cylindrical in shape and intended for one of two primary purposes:

1. As a permanent, load-bearing component of a foundation.
2. As a shell or casing to form cast-in-place concrete piles.

The key distinction to make is that A252 pipe is not intended for the transport of fluids under pressure. Its entire focus is on structural integrity and foundation performance.

Why ASTM A252 is the Ideal Choice for Piling

While other pipes might look similar, the A252 standard includes several features that make it uniquely suited for foundation work.

1. A Clear Focus on Minimum Yield Strength

From a structural engineering perspective, the most important property of a pile is its ability to handle loads without permanent deformation.

• The Standard: ASTM A252 is primarily concerned with minimum yield strength, offering three distinct grades:
  • Grade 1: Minimum Yield Strength of 30 ksi (207 MPa)
  • Grade 2: Minimum Yield Strength of 35 ksi (241 MPa)
  • Grade 3: Minimum Yield Strength of 45 ksi (310 MPa)
• Why it matters: This allows engineers to select the precise grade that matches their design load calculations, ensuring both safety and economic efficiency.

2. Requirements for Straightness

A pile must be driven straight into the ground to perform as designed.

• The Standard: ASTM A252 contains specific tolerances for the straightness of the pipe.
• Why it matters: This ensures the pile can be driven effectively and that the load is transferred axially to the bearing soil or bedrock. A pile that is not straight could buckle under load, compromising the entire foundation.

3. Flexible Chemical Requirements for Cost-Effectiveness

This is a unique and deliberate feature of the A252 standard.

• The Standard: Unlike standards for pressure pipe (like API 5L), ASTM A252 does not have strict limits on the chemical composition of the steel, such as phosphorus content.
• Why it matters: This flexibility allows manufacturers to utilize a wider range of steel sources. Since the pipe’s primary role is to provide structural strength and not to contain high-pressure fluids or resist specific types of corrosion, these stringent chemical controls are unnecessary. This makes A252 pipe a highly economical and readily available solution for foundation work.

The Allland Steel Advantage for Piling Projects

Building a foundation you can trust for generations starts with materials you can rely on today. At Allland Steel, we manufacture high-quality LSAW and SSAW pipe piles that meet and exceed the requirements of ASTM A252 in all three grades. Our capabilities in producing large-diameter and heavy-wall pipes make us an ideal partner for major infrastructure projects.

We understand the critical role these products play. Our commitment to quality ensures that the piles we deliver will form the bedrock of a safe and successful construction project.

To discuss the piling requirements for your next bridge, building, or marine project, contact a specialist at Allland Steel.

In any industrial purchase, especially for critical materials like steel pipe, traceability and the verification of quality are paramount. The Mill Test Certificate (MTC)—also known as a Mill Test Report (MTR)—is the primary document that provides this assurance.

A common and important question we receive, particularly from clients involved in European or major international projects, relates to the EN 10204 standard. This standard is the key to understanding the different levels of material certification and what they mean for your project’s quality assurance. Our goal is to clarify what this standard entails and what you can expect from Allland Steel.

What is EN 10204?

EN 10204 is a European Standard that specifies the different types of “inspection documents” that can be provided to a purchaser for metallic products. In short, it creates a standardized, universally understood system for certifying that a product’s chemical and mechanical properties conform to the specifications of the order. It ensures that both manufacturer and buyer are speaking the same language when it comes to quality documentation.

The Key Certificate Types Explained

EN 10204 defines several document types, but in the steel pipe industry, the most relevant are Type 2.2, Type 3.1, and Type 3.2.

Type 2.2: Test Report

This is a document in which the manufacturer declares that the products are in compliance with the order and provides results of non-specific inspection. This means the test results are based on the manufacturer’s regular quality procedures and may not be from the actual batch of material being delivered.

Type 3.1: Inspection Certificate 3.1

This is the most common and widely accepted certificate for industrial applications.

• What it is: A certificate issued and validated by the manufacturer’s authorized inspection representative, who must be independent of the manufacturing department.
• What it contains: It affirms that the products are compliant with the order and, crucially, includes the specific test results from the actual batch of products being supplied.
• Why it matters: From a quality assurance perspective, the Type 3.1 certificate provides the essential, traceable link between the physical product you receive and the specific tests that prove its compliance with the required standards.

Type 3.2: Inspection Certificate 3.2

This is the highest level of certification under EN 10204.

• What it is: A Type 3.1 certificate that has also been countersigned and validated by an independent third-party inspection authority (such as Lloyd’s Register, DNV, TÜV) or the purchaser’s own authorized inspector.
• Why it’s used: This is required for the most critical applications (e.g., nuclear power, certain offshore or pressure vessel components) where project specifications demand an impartial, external validation of the manufacturer’s test results.

What Type of MTC Does Allland Steel Provide?

At Allland Steel, our standard practice for all orders requiring specific material validation is to provide a Type 3.1 Mill Test Certificate in accordance with EN 10204.

This MTC provides full traceability for your order, detailing the specific:

• Chemical composition analysis
• Mechanical properties (Yield Strength, Tensile Strength, Elongation)
• Results of any other required tests, such as impact toughness or hydrostatic tests.

For projects with exceptional quality assurance requirements, we also have extensive experience in facilitating Type 3.2 certification. We can coordinate with the independent third-party inspection agency of your choice to provide this higher level of validation.

We believe that full transparency is the foundation of trust. Our adherence to the EN 10204 standard ensures that you receive clear, reliable, and internationally recognized documentation for the quality of your materials.

If your project has specific certification requirements, please contact the Allland Steel team to discuss them in detail.