ISO 3183 L320 Pipe

ISO 3183 L320 Pipe for Oil & Gas Transmission – High-Strength Pipeline Solutions from LONGMA GROUP

Hebei Longma Group Limited manufactures ISO 3183 L320 Pipe with a minimum yield strength of 320 MPa, designed for medium- to high-pressure oil, gas, and water transmission projects worldwide. LONGMA GROUP has more than 20 years of steel pipe manufacturing expertise, and its annual output is more than 1,000,000 tons, and it can provide high-quality L320 pipes in outer diameters from 60.3mm to 2032mm and wall thicknesses from 4mm to 100mm. We have a plant of 230,000 square metres, and we sell to more than 90 countries. All products are created to exacting international standards and with full quality documentation.

What is ISO 3183 L320 Pipe?

The product is a medium-strength pipeline steel type often utilised in oil and gas transmission systems. The marking “L320” means a minimum specified yield strength of 320 MPa, which is a technical equivalent to API 5L Grade X46.

This grade offers a good compromise between strength and weldability. It is often specified for applications needing stronger pressure resistance than lesser grades like as L245, or L290, while preserving acceptable fabrication qualities throughout construction.

The L320 pipe may be manufactured using ERW (Electric Resistance Welded), LSAW (Longitudinal Submerged Arc Welded) and seamless procedures. LONGMA GROUP specialises in ERW and LSAW manufacturing, and can guaranty constant quality for big volume orders.

Technical Specifications

Key Manufacturing Advantages

LONGMA GROUP has more than 20 years experience to manufacture big diameter and thick wall steel pipe. We use state-of-the-art heat treatment technology to maximise weld seam performance and improve overall pipe integrity.

We only buy raw materials from famous Chinese steel mills like Shagang, TISCO, BX Steel and Bao Steel. Stable quality of the material and complete traceability from steel plate to final product is guaranteed.

We have professional inspection equipment in our manufacturing lines, such as 100% hydro test, ultrasonic inspection, spectrographic analysis and mechanical testing. All pipes undergo stringent quality control procedures to identify any defects and to meet the criteria of ISO 3183 standards.

You gain from our ability to provide you with specialised fabrication and surface protection services. We provide welding, perforating, expansion processing, hot dip galvanising, FBE coating and 3LPE coating to satisfy your individual project needs.

Quality Assurance and Testing

Quality control for ISO 3183 L320 Pipe focuses on critical inspection items that directly impact pipeline safety. Mandatory tests include 100% hydrostatic testing to verify pressure integrity without leakage or deformation.

Non-destructive testing such as ultrasonic or radiographic inspection is applied to longitudinal or helical weld seams. This detects internal flaws, inclusions, or other defects that could compromise structural performance.

For PSL2 orders, additional testing includes Charpy V-notch impact testing at specified temperatures, drop weight tear testing, and fracture toughness evaluation. These tests ensure the material can arrest running cracks in high-pressure gas service.

LONGMA GROUP offers full technical documentation such as Material Test Certificates (MTC), Inspection and Test Plans (ITP), Manufacturing Procedure Specifications (MPS), and dimensional inspection reports. Documentation facilitates easy project approval and foreign procurement.

Applications Across Industries

It finds extensive use in oil and gas pipelines where you anticipate medium to high internal pressures. It can safely transport hydrocarbons over long distances due to its higher yield strength.

The grade is also defined for water transmission systems, infrastructure projects and energy facilities. Its combination of strength, weldability and dimensional correctness makes it appropriate for harsh service circumstances.

Engineers commonly pick the product when optimising pipeline design. The enhanced strength means that in certain circumstances wall thickness may be lowered compared with lesser grades, helping to save material consumption and total project costs.

Why Choose LONGMA GROUP for Your L320 Pipe Supply?

You gain access to stable production capacity exceeding 1 million tons annually. This ensures reliable supply for large-scale projects and repeat orders across multiple phases.

Our goods are manufactured in compliance with international standards such as ISO 3183, API 5L, ASTM, EN10219 and AS / NZS 1163. We are certified with API 5L Certificate , ISO 9001 , ISO 14001 and ISO 18001 .

We have successfully supplied steel pipes to clients in more than 90 countries. We have expertise working with engineering contractors, distributors and importers and we provide straightforward communication and fast logistics.

Complete pre-order support for clarifying technical needs. Our staff helps you develop specifications for your pipe, performance objectives, NDT needs and coating alternatives before manufacturing starts.

FAQ

Q：Why should we select the product instead of lower grades such as L245 or L290?

A: ISO 3183 L320 is a medium-strength pipeline steel grade having a minimum specified yield strength of 320 MPa, providing increased load-bearing capability compared to lesser grades such as L245 and L290. L320 is selected for increased pressure resistance and is thus appropriate for oil and gas transmission pipes with more demanding service. It may enable thinner walls under the same design circumstances, helping to minimise material consumption and shipping costs. L320 has enhanced mechanical performance, while retaining acceptable fabrication qualities. Final material selection should be based on pipeline design parameters including operating pressure, service temperature, pipeline diameter, transportation medium, and project specifications.

Q：What inspection and quality requirements should we confirm before purchasing products?

A：You need to ensure the supplier can fully comply with ISO 3183 requirements and provide complete quality documentation. This includes Mill Test Certificate (MTC) with full heat number traceability, chemical composition analysis, mechanical test results covering yield strength, tensile strength, and elongation, hydrostatic test records, non-destructive testing reports, dimensional inspection reports, and visual inspection records. For PSL2 requirements, additional quality controls may be required including Charpy V-notch impact testing, stricter chemical composition control, maximum hardness requirements, and additional weld seam inspection requirements. You should clearly define all inspection requirements in the purchase order to avoid quality disputes during production or delivery.

Q：What technical information should we confirm with the supplier before ordering products?

A：Before placing an order, you should confirm pipe outside diameter, wall thickness, pipe length, manufacturing process, PSL1 or PSL2 requirement, and pipe end type. You should also define performance requirements including minimum yield strength and tensile strength, impact test temperature and energy requirements, hydrostatic test pressure, NDT requirements for pipe body and weld seam, and coating and corrosion protection requirements. Evaluate supplier capability including previous experience supplying product, production capacity and delivery schedule, availability of third-party inspection from agencies such as BV, TUV, or Intertek, and ability to provide complete manufacturing records and traceability documents. A reliable supplier should demonstrate stable quality control, production capability, and full documentation support throughout the project.

Contact Us

Ready to source high-quality ISO 3183 L320 Pipe for your oil, gas, or water transmission project? Contact Hebei Longma Group today for technical support, quotations, and delivery schedules. Reach us at info@longma-group.com.