Q195 / Q235 / Q345 Carbon Steel Pipe

Q195, Q235 and Q345 are well-established carbon structural steel and low-alloy high-strength steel grades. We produce seamless pipes, ERW straight welded pipes and SSAW spiral submerged arc welded pipes based on these grades, manufactured in accordance with ASTM A53, ASTM A106 and other international specifications. Our products are widely used in onshore oilfield gathering systems, crude oil transmission lines, oil & gas process piping networks and auxiliary pipelines for oil stations. Complete physical, chemical and NDT documentation is available to satisfy audit requirements from oil project owners, supervisors and third-party inspection agencies worldwide. Balancing reliable performance and cost efficiency, these pipes are the preferred solution for low and medium-pressure oil & gas transportation services.

Q195

Low-carbon steel with excellent ductility, elongation, cold forming and weldability. Stable forming performance and consistent wall thickness. It is easy for on-site cutting, bending and opening works.

Typical service: low-pressure auxiliary oilfield pipelines, instrument tracer lines, drainage and water injection branches, temporary process lines, low-pressure branch networks at oil and gas stations.

Note: Relatively low yield strength. Not recommended for high-pressure, heavy-load pipelines or main oil lines requiring strict low-temperature impact resistance.

Q235

General-purpose carbon structural steel with balanced mechanical properties. Proven welding performance, wide size range and good compatibility with standard fittings and flanges. It has been widely adopted in oilfield surface facilities for decades.

Typical service: conventional oilfield gathering lines, short-distance crude oil transportation, process piping inside oil plants, conduit pipes for oilfield steel structures, low-pressure oil & gas networks.

Features: Stable performance under ambient temperature conditions, easy fabrication, sufficient stock and competitive lead time.

Q345

Low-alloy high-strength structural steel with trace alloy additions. It delivers much higher yield strength than Q235, together with improved tensile strength, low-temperature impact toughness and resistance to deformation and external collapse. It performs reliably for exposed, buried pipelines and sites with complex geological conditions.

Typical service: medium-pressure crude oil gathering trunk lines, remote field oil pipelines, long-distance buried transmission lines, pipelines under soil overburden load or span support.

Features: Capable of withstanding higher working pressure and external loads, resistant to ground settlement and rough field environments.

Seamless Steel Pipe: Hot rolled / hot expanded. High dimensional accuracy with no weld seam, eliminating weld failure risk. Preferred for critical process branches at oil stations. Available in small and medium diameters with wall thickness made to Schedule standards.

ERW Straight Welded Pipe: High-frequency electric resistance welding. Narrow weld and small heat-affected zone, good roundness and uniform wall thickness. Ideal for mass supply of medium & small diameter gathering pipelines with high production efficiency.

SSAW Spiral Welded Pipe: Main option for large-diameter long-distance buried crude oil trunk lines. Supports large OD and medium-heavy wall customization, highly compatible with anti-corrosion coating treatment.

Pipe end options: plain end, standard bevel end (30° / 37.5°), with protector caps. Dimensions: outer diameter, wall thickness and fixed lengths (6m / 9m /12m or custom cut lengths) are available per drawing.

Buried oil pipelines are constantly threatened by soil corrosion, stray current and moisture. We provide multiple coating systems tailored to oilfield conditions:

Basic finish: Shot blasting + anti-rust oil, for indoor storage, above-ground piping and short-term service.

Main buried solution: 3PE three-layer polyethylene coating, 3PP three-layer polypropylene coating. Outstanding adhesion, cathodic disbondment resistance and resistance to acidic/alkaline soil, the most popular choice for buried oil & gas pipelines.

Optional coatings: Coal tar epoxy, FBE fusion bonded epoxy coating, to match different soil chemistry and client technical specifications.

✅ Test items: Spectrochemical analysis, tensile test, bend test, flattening test, impact test (on request), hydrostatic test.

✅ NDT: UT ultrasonic testing, RT radiographic testing, MT magnetic particle testing. 100% weld inspection available for welded pipes.

✅ Full documentation: Material Test Certificate (MTC), factory inspection report, NDT report, hydrotest record, coating inspection record.

✅ Accept third-party inspection: SGS, BV and other surveyors for witness fabrication and sampling.

✅ Supporting certificates: ISO9001 quality management certificate. API 5L documents can be arranged for tender and site admission.

1. Dual compliance with Chinese material standard and ASTM international standards. Complete certificates for easy approval in overseas oil projects.

2. Graded material selection from Q195 to Q345, covering low-pressure branches up to medium-pressure remote trunk lines for different pressure and field conditions.

Full product range: seamless, ERW and SSAW pipes from small to large diameter. 3. One-stop sourcing reduces procurement coordination work.

4. Mature anti-corrosion technology including 3PE / 3PP, extending service life of buried oil pipelines significantly.

5. Flexible fabrication: pipe ends, marking, packing and cut lengths customized to project requirements.

6. Hydrostatic test and NDT inspection before shipment to minimize leakage risk for oil medium transportation.

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