3.2 Certificate, TPI inspection and delivery process description

DLSS - Pipe&Tube - 3.2 Certificate, TPI inspection and delivery process description

Product Information

ASME SA179 Seamless U-tubes ∅19.05 × 2.11min × L12210.9~13617.8mm, Total: 1,352 pcs

Project Background

The end user is a large energy and chemical company. Due to severe quality issues with previously sourced ASME SA179 tubes from India—leading to equipment shutdown and project suspension—the customer urgently needed to procure new tubes for heat exchanger remanufacturing and project restart.

As the core components of the heat exchanger, the quality of the tubes is critically important. The customer places great emphasis on this project. To ensure 100% compliance with standards and full inspection conformity, this order follows the EN10204-3.2 certification standard, with all inspection items witnessed on-site by the authoritative third-party agency Bureau Veritas (BV).

Below are the key inspection highlights and process optimizations. The entire process is traceable and fully transparent.

Inspection Highlights & Technical Enhancements

1) Sufficient Stock Prepared to Ensure Safe Project Delivery

To account for sampling inspections and potential losses during on-site installation, we produced an additional quantity of tubes as buffer for third-party sampling and customer backup. In the final delivery, we provided 10 extra tubes FREE OF CHARGE as SUPPORT to help ensure smooth project progress.

2) Upgraded Heat Treatment Process to Enhance Product Performance

To meet the customer’s higher performance demands in actual application, the standard annealing process (Annealing at 650°C) was upgraded to normalizing treatment (Normalizing at 870°C ~ 920°C). This significantly improved the uniformity of the tube structure and mechanical properties, ensuring reliable operation under the high-temperature, high-pressure conditions of heat exchangers.

3) Stricter Chemical Composition Control – Beyond Standard Requirements

In addition to fulfilling ASME SA179 standard requirements for C, Mn, P, S, etc., the customer imposed additional limits: Cu+Ni+Cr ≤ 0.15 and CE ≤ 0.43. These special requirements were communicated to BV in advance. All samples were witnessed, collected, and tested on-site by BV. All test results fully met the customer’s stringent requirements, reinforcing their confidence in our quality control capabilities.

4) Comprehensive U-Bend Tube Quality Verification – Highly Recognized by Customer

The smaller the U-bend radius, the greater the manufacturing difficulty and risk of wall thinning or structural damage. This order includes U-bends with a minimum radius of R = 30.52 mm. To ensure quality, we implemented the following special inspections:

100% Dye Penetrant Testing (DPT) – witnessed by BV on-site for all tubes

Destructive Testing – cutting through the midpoint of the smallest U-bend to assess wall thinning

Test Results – The maximum wall thinning rate was well below the customer’s allowable limit of 17%, earning high customer satisfaction

Conclusion

Through the rigorous quality control and inspection measures above, we ensured the full compliance, traceability, and superior quality of this batch of ASME SA179 Seamless U-tubes. This demonstrates DLSS’s technical expertise and delivery capabilities as a professional manufacturer supporting high-end projects.

Why Choose DLSS as Your Stainless Steel Tube Partner?

With over 30 years of experience and exports to 40+ countries, DLSS offers:

  • Customized tube solutions for heat exchangers and condensers
  • Full compliance with ASTM/ASME standards
  • Third-party inspections and full quality reports
  • Precision production, fast delivery

 Contact us today to get a free consultation or quote: info@dlsspipe.com

Wonderful! Share This Case:

Austenitic Stainless Steel

Duplex Stainless Steel

Nickel Alloys

▪ Incoloy Family

▪ Inconel Family

▪ Monel Family

▪ Hastelloy Family

▪ Other Special Alloys

Cobalt Alloys

Related Posts

ASTM A213 vs A269: What’s the Difference in Heat Exchanger Tubing?

ASTM A213 vs

Introduction Two of the most frequently specified standards for stainless steel tubing are ASTM A213 and ASTM A269. Both cover austenitic stainless steel tubes like TP304L, TP316L, and TP321. However, their scope, tolerances, and test requirements differ significantly—especially for heat exchanger and pressure service applications. This article provides a clear,...

Read More
Extruded Finned Tubes: Corrosion Resistance and Marine Applications

Extruded Finned Tubes:

In environments where moisture, saltwater, or harsh chemicals are present, corrosion resistance is one of the most critical factors in heat exchanger performance. Extruded finned tubes are specially designed to meet these challenges, making them the go-to choice for marine and offshore industries. If you want to understand the full...

Read More
Integrated Stainless Steel Piping Solutions for Industrial Projects

Integrated Stainless Steel

Introduction In large-scale industrial projects—such as oil refineries, power plants, food processing lines, and chemical facilities—procurement teams often face a key challenge: how to consolidate material supply while ensuring technical compliance and on-time delivery. DLSS offers a complete stainless steel piping solution, including seamless pipes, fittings, flanges, and documentation services...

Read More
ASTM A312 vs ASTM A789: Which Stainless Steel Tube Standard Is Right for Oil & Gas Applications?

ASTM A312 vs

Introduction In the oil and gas sector, selecting the right stainless steel tube standard is essential for long-term system performance. Among the most referenced specifications are: While both serve critical purposes in petroleum refining, offshore rigs, and midstream transport systems, they differ significantly in material composition, mechanical properties, and application...

Read More
Electropolished Tubing: When and Why to Use It

Electropolished Tubing: When

Introduction In industries where surface purity, cleanliness, and corrosion resistance are paramount, electropolished (EP) tubing is no longer optional—it’s a necessity. Whether you’re building pharmaceutical cleanrooms, semiconductor cooling loops, or biotech reactors, EP tubing ensures the performance, sterility, and durability that standard stainless steel tubes can’t match. This article explains...

Read More

How to Read

Introduction Mill Test Certificates (MTCs) are essential documents that verify the compliance and traceability of stainless steel tubes with international standards. Whether you’re a procurement officer, quality inspector, or EPC project engineer, the ability to read and interpret an MTC correctly is critical to ensuring product reliability and certification accuracy....

Read More
Top 10 Materials Used in Industrial Pipeline Engineering

Top 10 Materials

Introduction Choosing the right material is one of the most critical decisions in pipeline engineering. The material affects not only the strength, corrosion resistance, and temperature tolerance of the pipeline but also impacts cost, lifespan, and safety. Whether you’re designing for oil & gas, chemical processing, power plants, or marine...

Read More
Green Energy and ESG: How Sustainability Is Reshaping the Stainless Steel Seamless Tube Market

Green Energy and

The stainless steel seamless tube industry is undergoing a quiet but profound transformation—not just driven by technical demands, but by Environmental, Social, and Governance (ESG) goals and the global energy transition. As governments, investors, and end-users demand cleaner, longer-lasting, and traceable materials, tube manufacturers are under growing pressure to reduce...

Read More

Request A Quote

*We respect your confidentiality and all information are protected.