Seamless Steel Pipe

Seamless Steel Pipe Manufacturer & Supplier | Kun Yu

Seamless steel pipe manufacturer Kun Yu produces hot-rolled and cold-drawn seamless steel pipes conforming to ASTM, API, EN, and DIN standards for critical pressure piping and heavy structural applications. Direct mill supply from primary manufacturing facilities with original Mill Test Certificates (EN 10204 3.1), verified non-destructive testing, and strict dimensional tolerances for global industrial procurement.

Why Choose Kun Yu

Technical Specification Review

Our engineering team verifies your material grade, dimensional tolerances, and design standards prior to quotation. This pre-order review eliminates technical mismatches and ensures compliance with your project specifications.

Integrated Manufacturing & R&D Expertise

By combining production capabilities with material research, Kun Yu evaluates custom steel formulations, heat treatment requirements, and tight dimensional tolerances tailored to high-pressure and low-temperature applications.

Tailored Order Execution

We accommodate specialized project demands, including custom lengths, non-standard wall thicknesses, specific end-preparations, and customized bundle packaging to optimize on-site installation.

Comprehensive Export Coordination

We streamline international trade by managing product marking, mill test certifications, customs documentation, and sea/land shipping logistics aligned with standard Incoterms (FOB, CFR, CIF).

Technical Specifications

Parameter	Specification
Manufacturing Method	Hot Rolled, Cold Drawn, Cold Rolled
Outer Diameter (OD)	1/8” – 36” (10.3 mm – 914.4 mm)
Wall Thickness (WT)	SCH 10 to SCH XXS (1.73 mm – 80 mm)
Length Options	SRL (5–7m), DRL (10–12m), Custom Cut (up to 18m)
Carbon Steel Grades	ASTM A106 Gr B, ASTM A53 Gr B, API 5L PSL1/PSL2 Gr B to X70
Alloy & Structural	ASTM A335 P11/P22/P91, EN 10210 S355J2H
End Processing	Plain Ends (PE), Beveled Ends (BE per ASME B16.25), Threaded & Coupled
Coating Options	Bare, Black Varnish, Anti-Corrosion Oil, 3LPE, FBE, Hot-Dip Galvanized

Key Performance

Homogeneous Seamless Structure: Formed from solid round billets without any welded seam, our seamless pipes eliminate weld-zone vulnerabilities, providing superior structural strength and uniform stress distribution under high pressure.

Certified Mechanical Strength: Every heat batch is tested to confirm yield strength, tensile strength, elongation, and impact toughness, strictly matching the threshold values defined by API and ASTM criteria.

Strict Dimensional Tolerances: Controlled wall thickness eccentricity and consistent outer diameter dimensions ensure smooth field alignment, hassle-free machining, and reliable automated welding.

Surface Integrity & End Finishing: Uniform surface cleaning, rust-preventative coatings, and precise end beveling (30 degrees to 37.5 degrees) prepare the pipes for immediate field fit-up and fabrication.

Environmental Suitability: Selected material grades are engineered to withstand sour service (H2S environments), sub-zero operating temperatures, and elevated steam pressures.

Industry Applications

Oil, Gas & Petrochemical Piping: Used for upstream drilling, midstream transport lines, and downstream refinery processing units handling crude oil, natural gas, hydrocarbons, and chemical fluids under high pressure.

Power Generation & Boiler Systems: Supplied as high-pressure boiler tubes, superheater lines, reheater pipes, and heat exchanger tubing designed for elevated steam temperatures and thermal stress.

Mechanical Engineering & Heavy Machinery: Utilized by OEMs for hydraulic cylinders, precision structural sleeves, driveshafts, bushings, and heavy equipment structural frameworks requiring uniform wall strength.

Construction & Structural Engineering: Applied in offshore jacket platforms, bridge piling, stadium steel frameworks, and industrial architectural trusses where high load-bearing capacity is required.
Water & Industrial Utility Lines: Deployed in high-pressure water distribution, firefighting networks, high-pressure air systems, and industrial plant utility piping.

Engineering & Procurement Selection Guide

Define Service & Operating Parameters: Identify the temperature range, maximum allowable working pressure (MAWP), fluid composition, and environmental exposure (H2S, marine, corrosive soil).

Select Standard & Material Designation: Match your design code (ASME B31.3, API 5L, EN 13480) with the exact material grade (API 5L X52 PSL2 or ASTM A335 P11).

Specify Size, Schedule & Tolerances: State nominal pipe size (NPS), Schedule (SCH), outer diameter, wall thickness, and length tolerances (12m fixed length +/- 10 mm).

Establish Quality Inspection Level: Define required non-destructive testing (Ultrasonic, Eddy Current, Radiographic) and mechanical testing (Charpy V-Notch impact test, Hardness test).

Confirm Documentation & Certification: Specify mandatory quality records prior to ordering, such as EN 10204 3.1 MTC, PMI reports, or ISO/API compliance certificates.

Quality Assurance & Inspection Protocols

01/

Chemical & Material Verification
Every steel heat undergoes Spectrometric PMI analysis to verify chemical composition against specified limits for Carbon, Manganese, Silicon, Phosphorus, and Sulfur.

02/

NDT & Pressure Testing
Pipes undergo 100% Hydrostatic testing along with Non-Destructive Examination (NDE)—including Ultrasonic Testing (UT) or Eddy Current Testing (ET)—to detect surface and internal flaws.

03/

Mechanical Property Testing
Tensile testing, flattening tests, bending tests, and Charpy impact testing (at ambient or sub-zero temperatures) are conducted on sample specimens per batch.

04/

Full Traceability & Third-Party Inspection
Each pipe length is stenciled with Heat Number, Grade, Size, and Standard. We fully support third-party inspection agencies including SGS, Bureau Veritas (BV), TÜV, and Intertek.

Customized Manufacturing & Processing Services

Custom Cutting & Length Management

We offer precise fixed-length cutting (down to +/- 2 mm tolerance) to minimize material waste and cut field installation time.

Custom End Preparation & Machining

In addition to standard 30-degree beveling, we supply custom J-bevels, square cuts, internal counterboring, and threading according to client fabrication drawings.

Specialized Surface Treatment & Coating

Options include internal epoxy lining, external 3LPE/3LPP anti-corrosion coating, hot-dip galvanizing, and temporary rust-inhibiting black varnish.

Contract & Frame Agreement Supply

For recurring industrial demand or multi-phase EPC projects, we maintain dedicated production slots and inventory reserves under long-term supply agreements.

Global Packaging & Export Logistics

Protective Packaging Options

Small Diameters (OD <= 8"): Hexagonal bundles bound with heavy-duty steel strapping, equipped with lifting slings for easy crane unloading.
Large Diameters (OD > 8"): Loose shipment with protective plastic end caps or wooden end protectors to prevent thread/bevel damage.

Export Markings & Tagging
Each bundle and pipe features clear weather-resistant tags detailing Manufacturer, Heat Number, Specification, Standard, Size, Bundle Number, and Destination Port.

Container & Bulk Logistics Planning
Shipment options are optimized via 20ft/40ft GP/HQ containers, open-top containers, or Breakbulk vessels to optimize freight costs and ensure safe transit.

Full Shipping Documentation
We issue complete commercial invoices, packing lists, Bills of Lading, Certificates of Origin (Form E, Form F, FTA), and EN 10204 3.1 Material Test Certificates.

Frequently Asked Questions

Q: What standards and grades does Kun Yu specialize in?

A: We supply seamless pipes according to API 5L (Gr. B through X70), ASTM A106/A53 (Gr. B), ASTM A333 (Gr. 6), ASTM A335 (P5, P11, P22, P91), and EN 10216-2 (S235, S355).

Q: What inspection certificates are provided with the delivery?

A: All orders are supplied with standard EN 10204 3.1 Material Test Certificates (MTC). Third-party inspection reports (EN 10204 3.2) issued by SGS, BV, or TÜV are available upon request.

Q: Can Kun Yu supply custom wall thicknesses or non-standard lengths?

A: Yes. We process custom heavy-wall dimensions and cut-to-length orders ranging from 3 meters to 18 meters according to your engineering drawings.

Q: What is the lead time for standard and custom orders?

A: Stock inventory items can be dispatched within 7–10 days. Custom production orders typically require 20–35 days, depending on steel grade, quantity, and coating requirements.

Q: How do you protect pipe bevels and surfaces during ocean shipping?

A: All bevels are fitted with plastic end caps or metal bevel protectors. Pipe surfaces are coated with anti-rust varnish or protective oil, and bundles are securely strapped for maritime transportation.

Request a Project Quote

Submit Your Technical RFQ Contact the Kun Yu sales engineering team for direct mill pricing, stock verification, and detailed delivery schedules.
Information Required for Rapid Quotation:
Material Specification & Grade (ASTM A106 Gr B, API 5L X52 PSL2)
Pipe Dimensions: Outer Diameter (OD) and Wall Thickness (WT / Schedule)
Total Quantity (Meters, Metric Tons, or Total Lengths)
Length Requirements (Single Random, Double Random, or Fixed Length)
End Treatment & Surface Coating Requirement
Destination Port & Expected On-Site Date

As one of the leading seamless steel pipe manufacturers and suppliers in China, we warmly welcome you to wholesale cheap seamless steel pipe from our factory. All customized steel products are with high quality and competitive price. For free sample, contact us now.