API 5L X46QS Seamless Steel Pipe For Sour Service And Harsh Oil & Gas Pipeline

Executive Standard: API 5L 44th Edition, ISO 3183, NACE MR0175, NACE TM0284

Grade: API 5L X46QS (L320QS)

Product Specification Level: PSL 2

Manufacturing Process: Hot rolling + Quenched & Tempered (Q&T)

Applicable Service: Sour oil & gas service, H₂S-containing fluid transmission

API 5L X46QS (also designated as L320QS) is a premium-grade seamless line pipe engineered forsour service and harsh oil & gas pipeline environments. Manufactured in strict accordance with API 5L 44th Edition Annex H and ISO 3183 standards, this seamless pipe adopts quenched and tempered heat treatment process, featuring excellent hydrogen-induced cracking (HIC) resistance, sulfide stress cracking (SSC) resistance and stable mechanical properties.

Different from conventional X46 carbon steel pipes, the X46QS grade is specially optimized for acidic working conditions with H₂S medium. It integrates high strength, superior toughness and reliable corrosion resistance, making it the ideal pipeline solution for onshore and offshore oil and gas gathering, transmission and medium-pressure fluid delivery projects.

 1.  Chemical Composition (Max, %)

2.Mechanical Properties

3.Dimension Range & Tolerance

Outer Diameter (OD): 70mm ~ 610mm (custom inch sizes available)

Wall Thickness (WT): 6mm ~ 35mm (Schedule 20 to XXS)

Length: Single random length (5-7m), double random length (9-13m), customized fixed length

Diameter Tolerance: ±0.75% (API 5L standard)

Wall Thickness Tolerance: +15% / -12.5%

Pipe End: Plain end, beveled end, threaded & coupled end

4.Testing & Certification

Special Tests: HIC test (NACE TM0284, 96h), SSC test, hydrogen embrittlement resistance test

Conventional Tests: Hydrostatic test, ultrasonic testing, tensile test, impact test, chemical spectral analysis

Certificates: EN 10204 3.1/3.2 material certificate, SGS/TUV third-party inspection report

API 5L X46QS seamless pipes are specially designed forsour and corrosive oil & gas industrial scenarios, widely applied in global energy engineering projects:

• Oil & Gas Field Development: Gathering and transmission pipelines for sour crude oil and natural gas containing hydrogen sulfide
• Onshore & Offshore Pipeline Projects: Medium-pressure long-distance transmission pipelines for oil, gas and produced water
• Petrochemical Industry: Corrosive fluid delivery pipelines in petrochemical processing plants
• Energy Infrastructure: Municipal gas transmission pipelines, industrial fluid conveying systems
• Special Industrial Projects: Pipeline systems requiring strict anti-cracking and anti-corrosion performance in harsh geological environments

Q1: What is the difference between X46QS and ordinary X46 seamless pipe?

X46QS is a sour service grade pipe with optimized formula and quenched & tempered heat treatment. It has professional HIC/SSC anti-cracking performance, which can resist hydrogen sulfide corrosion. Ordinary X46 pipes have no sour resistance capability and are only suitable for conventional non-corrosive oil and gas transmission. QS grade is mandatory for H₂S-containing working conditions.

Q2: What does PSL2 grade mean for this pipe?

PSL2 (Product Specification Level 2) is the highest quality level of API 5L standard. Compared with PSL1, PSL2 requires stricter chemical composition control, mandatory low-temperature impact test, full-scale non-destructive testing and traceability management, ensuring higher safety and stability for critical pipeline projects.

Q3: Can you provide customized sizes and surface coatings?

Yes. We support customized outer diameter, wall thickness, fixed length and pipe ends. Optional surface treatments include 3LPE anti-corrosion coating, epoxy coating, paint coating and shot blasting, which adapt to different underground, marine and outdoor service environments.

Q4: What quality tests will be conducted before delivery?

All X46QS pipes undergo full-process inspection: chemical composition spectral analysis, mechanical property testing (tensile, impact, hardness), hydrostatic pressure test, ultrasonic non-destructive flaw detection, and sour resistance HIC/SSC tests. Complete test reports and official certificates are provided for each batch.

Q5: What is your delivery time and packaging standard?

Conventional sizes have sufficient stock with 3-7 days fast delivery; customized sizes take 15-25 working days. Standard packaging: bundled with steel strips, equipped with plastic end caps to protect pipe ends, wooden pallet packaging is optional, suitable for sea and land transportation to avoid damage.

Q6: Is X46QS pipe reusable and maintainable?

With excellent structural stability and corrosion resistance, X46QS seamless pipe has a service life of more than 20 years under standard working conditions. It features low maintenance cost, no frequent replacement, and can be reused after professional cleaning and inspection for secondary engineering applications.

How To Cooperate With Us?

Our address

Rm1406,14th/F No 208, Hongqi Road, Nankai Dist, Tianjin City ,China

Phone Number (WhatsApp/Wechat)

+86 16622033809

E-mail

alisa@tjshenzhoutong.com

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