Q&A About "Application & Selection"

The long-term stability of any major bridge, port facility, or high-rise building rests entirely on the strength and integrity of its foundation. In modern construction, steel pipe piles are a proven, high-capacity solution for these deep foundations, but a frequent and critical question we address is which type of pipe is best suited for the job.

From an engineering standpoint, making the right choice is key to ensuring a foundation that is both safe and cost-effective. This guide will walk you through the primary options and the factors you should consider.

The Governing Standard for Piling: ASTM A252

Before discussing specific pipe types, it’s essential to establish the governing standard. For piling applications in North America and many international projects, that standard is overwhelmingly ASTM A252.

As we’ve covered previously, this specification is written exclusively for steel pipe intended for use as a structural, load-bearing element. Any pipe selected for a piling project, whether LSAW or SSAW, should be specified to meet or exceed the requirements of ASTM A252, typically Grade 2 (35 ksi yield) or Grade 3 (45 ksi yield).

Evaluating the Primary Options: SSAW vs. LSAW

Both SSAW (Spiral Weld) and LSAW (Longitudinal Weld) pipes are widely and successfully used for piling. The best choice depends on your project’s specific geotechnical conditions, structural loads, and budget.

SSAW (Spiral SAW) Pipe Piles: The Industry Workhorse

For a significant number of piling projects, SSAW pipe is the preferred choice, and for good reason.

• Key Advantage – Cost-Effectiveness: The continuous, efficient manufacturing process of SSAW pipe often makes it the most economical option, particularly for projects requiring large quantities of piling.
• Performance: SSAW pipe provides excellent structural capacity and is perfectly suited for most foundation designs where the pipe is driven to a specific depth and often filled with concrete. The spiral nature of its weld can also contribute to the pipe’s overall rigidity.
• Ideal Use Cases: SSAW pipe piles are an outstanding solution for a wide range of applications, including building and warehouse foundations, trestle bridges, retaining walls, and communication towers.

LSAW (Longitudinal SAW) Pipe Piles: The Heavy-Duty Solution

When project demands become more extreme, LSAW pipe piles offer an additional level of performance and security.

• Key Advantage – Heavy-Wall Capability: The JCOE manufacturing process allows LSAW pipes to be produced with extremely heavy wall thicknesses. This makes them exceptionally resistant to damage and buckling during driving in very hard or obstructed ground conditions.
• Performance: The use of single, high-quality steel plates ensures very uniform mechanical properties throughout the pipe, which is a benefit in designs with high, concentrated loads.
• Ideal Use Cases: LSAW pipe piles are the necessary choice for the most demanding projects, such as foundations for major long-span bridges, deepwater marine terminals, and offshore wind turbine jackets where piles are subjected to extreme axial, lateral, and dynamic loads.

Key Selection Factors for Your Project

Our technical specialists typically advise clients to consider these three factors:

1. Geotechnical Conditions: Are you driving into soft clays or dense glacial till with boulders? Harsher driving conditions favor the robustness of a heavy-wall LSAW pipe.
2. Structural Loads: What are the final design loads the foundation must support? Exceptionally high compressive or lateral loads may necessitate the heavy-wall capabilities of LSAW.
3. Project Economics: Is this a standard foundation design in moderate soil conditions? If so, the high performance and cost-effectiveness of SSAW pipe make it a very compelling choice.

The Allland Steel Recommendation

Our guidance is to view SSAW pipe piles as the highly capable and economical baseline for the majority of foundation projects. For projects involving exceptional design loads, heavy-wall requirements, or particularly challenging driving conditions, upgrading to LSAW pipe piles provides a superior margin of safety and performance.

The optimal foundation solution depends on a thorough analysis of your project’s geotechnical report and structural design. The specialists at Allland Steel are experienced in supplying both LSAW and SSAW pipe piles for major infrastructure projects worldwide and can help you make the most effective material choice.

Contact a piling specialist at Allland Steel to review your project’s foundation requirements.

Planning a long-distance natural gas pipeline is one of the most complex undertakings in modern infrastructure. From our perspective as a key material supplier, we understand that while a project involves route planning, environmental assessments, and regulatory approvals, the integrity of the pipeline itself is the core of the entire system.

This guide outlines the critical technical considerations for pipe selection that are fundamental to ensuring a safe, reliable, and efficient natural gas transmission network for decades to come.

The Four Pillars of Pipeline Specification

Successfully specifying a pipe for natural gas transmission rests on four key pillars. Getting these right at the planning stage is essential for the project’s success.

Pillar 1: Standard and Specification Level (The Foundation of Safety)

This is the non-negotiable starting point for any gas pipeline.

• The Standard: The mandatory international standard for this application is API 5L.
• The Specification Level: For the vast majority of natural gas transmission lines, PSL2 (Product Specification Level 2) is the required choice.

Our expert guidance: While API 5L PSL1 is a valid standard for less critical applications, the high-pressure nature and significant public safety implications of gas transmission make the superior requirements of PSL2 essential. The mandatory fracture toughness, tighter chemical controls, and stricter testing protocols of PSL2 are fundamental to preventing failures and ensuring the pipeline’s integrity.

Pillar 2: Material Grade Selection (Balancing Strength and Economics)

The grade of steel determines its strength. Common grades for this application include API 5L X52, X65, and X70.

• The Principle: A higher-grade steel (like X70) has a higher yield strength than a lower-grade steel (like X52). This means a pipe with a thinner wall can safely contain the same amount of pressure.
• The Advantage: For long-distance pipelines, using a higher grade often leads to a lower total installed cost. While the cost per ton of the steel may be higher, the reduced wall thickness results in significant savings from:
  • Lower overall steel tonnage required.
  • Reduced transportation and handling costs.
  • Faster welding times and lower consumable costs on site.

The selection of steel grade is a critical economic and engineering decision that should be made early in the design phase.

Pillar 3: Pipe Type and Manufacturing (Ensuring Reliability)

For large-diameter natural gas mainlines, the manufacturing process is key to ensuring reliability.

• The Choice: High-quality LSAW (Longitudinal SAW) pipe is a preferred choice for this application. High-Frequency Welded (HFW) and Seamless pipes are also used, typically for smaller diameter lines.
• The Reason: As we’ve detailed previously, the LSAW manufacturing process is ideally suited for producing the heavy-wall, high-grade, and dimensionally precise pipe required for these critical projects. The straight weld seam is also easily and reliably inspected with advanced NDT methods.

Pillar 4: External Coating System (Guaranteeing Longevity)

A natural gas pipeline is designed to be a 50+ year asset. Its primary long-term threat is external corrosion from the soil.

• The System: The industry benchmark for high-performance protection is a three-layer coating system, such as 3LPE (Three-Layer Polyethylene) or 3LPP (Three-Layer Polypropylene).
• The Rationale: This system provides a dual defense: the inner FBE layer offers excellent anti-corrosion and adhesion, while the rugged outer polyolefin layer provides robust mechanical protection against damage during installation. Investing in a premium coating system is a critical decision to protect the pipeline for its entire design life.

The Allland Steel Partnership: From Specification to Supply

Successfully planning and executing a natural gas pipeline requires deep expertise at every stage. At Allland Steel, we provide the high-specification API 5L PSL2 LSAW pipe that forms the backbone of these critical infrastructure projects.

Our technical specialists understand these four pillars intimately and are ready to work with your engineering team. We can help ensure your material specifications are optimized for safety, performance, and long-term value.

To discuss the requirements for your natural gas pipeline project, contact a technical specialist at Allland Steel.

When specifying pipelines for potable (drinking) water, the selection criteria extend far beyond simple corrosion protection. The primary responsibility is to ensure public health by preserving the quality and safety of the water being transported.

A critical question we address for municipal engineers and water authorities is which coating and lining systems are both certified as safe for drinking water and durable enough to guarantee a long service life. From our perspective, this is a matter of both uncompromising compliance and proven performance.

The Non-Negotiable Requirement: Certification to NSF/ANSI/CAN 61

Before we discuss specific coating types, the single most important requirement must be addressed: safety certification.

Any material, coating, or lining that will come into contact with drinking water must be certified to NSF/ANSI/CAN 61: “Drinking Water System Components – Health Effects.” This is the internationally recognized standard that ensures a product will not leach harmful levels of contaminants, metals, or chemicals into the water.

Our expert guidance: Always demand proof of this certification for any internal lining you are considering. This is a non-negotiable benchmark for ensuring public safety and meeting regulatory requirements.

Recommended Lining and Coating Systems

Once the NSF/ANSI/CAN 61 certification is confirmed, you can choose from several excellent, high-performance systems for the pipe’s interior and exterior.

Internal Linings (Water-Contact Surfaces)

1. Cement Mortar Lining This has been the waterworks industry’s trusted solution for decades, and for good reason. A layer of cement mortar is centrifugally applied to the pipe’s interior, creating a dense, smooth surface.

• Advantages: It creates a stable, inert barrier that not only prevents the steel from corroding but also actively passivates the steel surface. It is exceptionally durable, long-lasting, and highly cost-effective, especially for large-diameter water transmission mains.

2. Liquid-Applied Epoxy Linings These systems consist of a two-part, 100% solids (solvent-free) epoxy that is spray-applied to the pipe’s interior.

• Advantages: Liquid epoxies create an extremely smooth, glossy surface that can improve the pipe’s hydraulic efficiency (known as the Hazen-Williams “C” factor), potentially reducing long-term pumping costs.
• Critical Factor: It is essential that the specific epoxy formulation is certified to NSF/ANSI/CAN 61 and is applied under strict quality controls to ensure correct thickness and a full cure.

3. Fusion Bonded Epoxy (FBE) Linings This is a factory-applied, thermosetting powder coating. As with liquid epoxies, the specific FBE powder used must be certified for potable water contact.

• Advantages: FBE provides a very tough, damage-resistant, and consistent internal lining. The factory-controlled application process ensures a high degree of quality control and a reliable finish. It’s a premium choice for combining water safety with a robust, durable surface.

External Coatings (Protection from the Environment)

While the internal lining protects the water, the external coating protects the pipe from soil corrosion, moisture, and other environmental factors. Since these coatings do not contact the drinking water, they do not require NSF certification. Excellent, high-performance choices include:

• 3LPE / 3LPP Systems
• Fusion Bonded Epoxy (FBE)
• Polyurethane Coatings

The choice of external coating depends on the soil conditions, installation method, and operational environment.

The Allland Steel Commitment to Water Safety

Protecting our water resources is a shared responsibility. At Allland Steel, we provide pipeline solutions that meet the stringent safety and performance standards required for modern water infrastructure. We can supply pipes with a range of NSF/ANSI/CAN 61 certified internal linings and highly durable external coating systems.

Our specialists are ready to help you analyze your project’s requirements to engineer the optimal and safest pipeline solution.

Contact an Allland Steel specialist to discuss your potable water pipeline project.