Seamless Boiler Tube ASTM Certified Mill Direct | Kuaima Steel Group

Kuaima Steel Co., Ltd.

Verified Custom manufacturer 7yrs

Technical Specifications of Seamless Boiler Tube

Property	Parameter	Description
Product Name	Seamless Boiler Tube	Hot-rolled or cold-drawn seamless steel tube for boiler and heat exchanger service
Material Grade	ASTM A106 Gr.B / SA210 Gr.A1 / SA213 T11 / T22 / 20G	Multiple grades available for medium- and high-pressure boiler applications
Standard Compliance	ASTM A106, ASTM A210, ASTM A213, EN 10216-2, GB 5310, JIS G3461	Meets international boiler tube manufacturing and testing standards
Carbon (C)	0.10 – 0.30%	Varies by grade; ensures adequate strength and weldability
Manganese (Mn)	0.29 – 1.06%	Enhances tensile strength and hardenability
Silicon (Si)	≤ 0.50%	Acts as deoxidizer and improves high-temperature oxidation resistance
Chromium (Cr)	0 – 2.50%	Present in alloy grades (T11/T22) for creep and oxidation resistance
Molybdenum (Mo)	0 – 1.05%	Improves elevated-temperature strength in alloy grades
Phosphorus (P) / Sulfur (S)	P ≤ 0.035% / S ≤ 0.035%	Controlled to minimize hot shortness and ensure toughness
Tensile Strength	415 – 590 MPa	Per ASTM A106 Gr.B ≥ 415 MPa; alloy grades up to 590 MPa
Yield Strength	205 – 310 MPa	Per ASTM A106 Gr.B ≥ 240 MPa; varies with grade and heat treatment
Elongation	≥ 22%	Minimum elongation in 50 mm gauge length per applicable standard
Dimensions (OD × WT × Length)	OD: 10.2 – 457 mm / WT: 1.5 – 50 mm / L: 4 – 18 m	Custom sizes available; tolerances per ASTM A450 or EN 10216-2
Surface Finish	Black painted / Oiled / Varnished / Bare	Anti-rust treatment applied; pickled or shot-blasted finish optional
Application	Power plant boilers, superheaters, reheaters, economizers, heat exchangers	Suitable for medium- and high-pressure steam service up to 600 °C
Certification	ISO 9001, PED 2014/68/EU, TÜV, BV, SGS, Lloyd's	Mill test certificate EN 10204 3.1 / 3.2 provided with each shipment
Packaging	Bundled with steel strips, plastic caps on ends, waterproof wrapping	Seaworthy export packaging; marking per customer or standard requirement
MOQ	1 Metric Ton	Smaller trial orders negotiable; lead time depends on specification

Seamless Boiler Tube ASTM Certified Mill Direct | Kuaima Steel Group

Seamless boiler tube is an essential component in power generation, petrochemical processing, and industrial heating systems where reliable performance under high temperature and pressure is non-negotiable. Manufactured through hot-rolling or cold-drawing processes without any welded seam, these tubes deliver superior structural integrity that welded alternatives simply cannot match. At Kuaima Steel Group, we supply ASTM-certified seamless boiler tubes directly from our partner mills, offering premium grade materials at cost-effective, mill-direct rates. Whether you operate coal-fired power plants, waste heat recovery boilers, or high-pressure steam generators, our seamless boiler tubes meet the rigorous demands of continuous service in extreme thermal environments.

What Is Seamless Boiler Tube?

A seamless boiler tube is a hollow cylindrical steel product manufactured from a solid round billet that is pierced and elongated without any longitudinal weld joint. This seamless construction eliminates the weakest point found in welded tubes — the seam — resulting in uniform grain structure and consistent wall thickness throughout the entire length. Seamless boiler tubes serve critical roles in water-tube boilers, superheaters, economizers, and reheater sections where they must withstand internal pressures exceeding 20 MPa and continuous operating temperatures up to 580°C (1076°F). The absence of a weld seam provides enhanced resistance to creep, fatigue, and stress corrosion cracking under prolonged high-temperature service.

Seamless boiler tube manufacturer

Seamless Boiler Tube Technical Specifications

Our seamless boiler tubes are manufactured in compliance with internationally recognized standards, ensuring traceability and performance reliability across all critical boiler applications.

Seamless boiler tube supplier

Parameter	Specification Details
Applicable Standards	ASTM A106 Grade B/C, ASTM A179, ASTM A192, ASTM A210 Grade A1/C, ASME SA213 T11/T22/T91, EN 10216-2, GB 5310
Steel Grades	20G, 15CrMoG, 12Cr1MoVG, SA106B, SA210C, T11, T22, T91, 16Mo3, 13CrMo4-5
Outside Diameter	10.0 mm – 630 mm (0.394″ – 24.8″)
Wall Thickness	1.5 mm – 60 mm (0.059″ – 2.362″)
Length	Random length 5–12 m, or cut-to-length per customer requirement
Tensile Strength	415 MPa min (SA192) / 485 MPa min (SA210 Gr.A1) / 585 MPa min (SA213 T91)
Yield Strength	240 MPa min (SA192) / 255 MPa min (SA210 Gr.A1) / 415 MPa min (SA213 T91)
Max Service Temperature	Up to 580°C (T91 grade) / 565°C (T22 grade) / 400°C (SA192 carbon steel)
Surface Finish	Black painted, varnished, oiled, or bare as specified
Testing	Hydrostatic test, flattening test, flaring test, ultrasonic examination per ASTM E213, eddy current per ASTM E309

Key Advantages of Our Seamless Boiler Tubes

Uniform Microstructure: The piercing and elongation process produces a homogeneous grain flow aligned along the tube axis, delivering a density of approximately 7.85 g/cm³ with no weld-induced heat-affected zones. This translates to consistent mechanical properties across every section of the tube.

Seamless boiler tube factory

Outstanding High-Temperature Performance: Alloy grades such as SA213 T91 (9Cr-1Mo-V) maintain a minimum tensile strength of 585 MPa at room temperature and exhibit exceptional creep rupture resistance at temperatures up to 580°C, enabling thinner wall designs and reduced overall boiler weight.

Comprehensive Non-Destructive Testing: Every seamless boiler tube from Kuaima Steel Group undergoes 100% ultrasonic testing per ASTM E213 and hydrostatic testing at pressures calculated per ASTM A530, ensuring zero-defect delivery for critical pressure service.

Dimensional Precision: Our tubes are supplied with outer diameter tolerances within ±0.5% and wall thickness tolerances within ±10% (or tighter per special order), meeting the precise fit-up requirements of modern boiler fabrication.

Applications

Seamless boiler tubes find extensive application in:

Utility and industrial water-tube boilers (subcritical and supercritical)
Superheater and reheater sections operating above 450°C
Economizer tubes for heat recovery systems
Petrochemical furnace tubes and heat exchangers
Combined cycle heat recovery steam generators (HRSG)
Nuclear power steam supply systems (with appropriate nuclear grade certification)

Frequently Asked Questions

What is the MOQ?

Our minimum order quantity for seamless boiler tubes is typically 1 metric ton per size and grade combination. For less common alloy grades such as T91 or T92, a minimum of 2 metric tons may apply depending on mill scheduling.

Do you provide material test certificates?

Yes. Every shipment includes original mill test certificates (MTC) per EN 10204 3.1, documenting chemical composition, mechanical properties, and non-destructive test results. Third-party inspection reports from SGS, TÜV, or BV are available upon request at additional cost.

What is the typical delivery time?

Standard carbon steel grades (SA192, SA210) in common sizes ship from stock within 7–10 business days. Alloy grades (T11, T22, T91) and non-standard dimensions require 30–45 days for mill production and quality inspection.

Can you cut to custom sizes?

Absolutely. We offer precision cut-to-length services with a tolerance of ±3 mm, along with beveling (30° or 37.5° per ASME B16.25), threading, and protective end-cap installation to meet your project-specific fabrication requirements.

Get a Competitive Quote for Seamless Boiler Tube

Kuaima Steel Group delivers ASTM and ASME certified seamless boiler tubes at mill-direct rates with full traceability and technical support. Contact our dedicated boiler tube specialists today with your required grade, dimensions, and quantity. We respond to all inquiries within 12 hours with detailed pricing and lead time confirmation — helping you keep your boiler projects on schedule and on budget.

Ratings & Reviews

5.0

Very satisfied

Based on 8 reviews for verified purchases

Supplier service

5.0

On-time shipment

5.0

Supplier service

5.0

Michael Tanner

United States

verified purchases

2025-02-14

Initial Marking Issue Resolved Professionally
Ordered 6 tons of SA213 T11 seamless tubes, OD 44.5mm x 4.0mm, for a reheater section operating at 500°C. The tube quality itself was fine — mechanical properties and NDT results all checked out against the MTC. However, about 30% of the bundles had faded stencil markings on arrival, which our inspector flagged as a traceability concern. Raised this with Kuaima and they responded within a day, provided supplementary documentation linking heat numbers to specific bundles, and arranged for re-marking instructions. Issue was resolved, but it shouldn't have happened on pressure-rated product.

Sarah Thornton

United Kingdom

verified purchases

2025-03-08

Competitive Pricing on 20G Boiler Tubes for Budget-Conscious Project
We needed 25 tons of GB 5310 grade 20G seamless boiler tubes (OD 57mm x 5.0mm) for an industrial boiler refurbishment where budget was tight. Kuaima's mill-direct model saved us a meaningful amount compared to European stockholders. Tubes arrived in good condition with all required Chinese and translated English test certificates. OD tolerance was within ±0.5% as promised. Delivery took 35 days — slightly longer than the 30 we hoped for, but within their stated 30-45 day window for mill production. Fair pricing for fully certified product.

Ahmed Al-Rashidi

UAE

verified purchases

2025-03-30

Good Value on SA106 Grade B — Minor Paperwork Delay
Ordered 15 metric tons of ASTM A106 Grade B seamless tubes, OD 114.3mm x 8.56mm, for a district cooling plant steam distribution upgrade in Abu Dhabi. Tube quality was excellent — uniform wall thickness, clean UT reports, and proper beveled ends per ASME B16.25. Pricing was roughly 8-10% below what we were quoted from two other suppliers for the same spec. Only issue was a two-day delay in receiving the final MTC documents after the cargo shipped, which caused a small hold-up at customs. Otherwise a solid transaction and good value overall.

David Morrison

Australia

verified purchases

2025-04-24

Third Order This Year — Consistently Reliable
This was our third purchase from Kuaima in 2025 — all SA210 Grade A1 seamless boiler tubes for water-tube boiler maintenance contracts across Queensland. Latest order was 9 tons, OD 50.8mm x 3.7mm, random lengths. Tensile strength tested at 510 MPa against the 485 MPa minimum. Flattening and flaring test results all passed without issue. What keeps us coming back is the combination of genuine mill-direct pricing, complete documentation, and the fact that they actually hold common carbon steel grades in stock for fast turnaround. Seven-day dispatch this time.

Stefan Brückner

Germany

verified purchases

2025-05-16

Smooth Procurement for 16Mo3 and 13CrMo4-5 Tubes
We sourced 22 tons of EN 10216-2 grade 16Mo3 (OD 60.3mm x 5.0mm) and 6 tons of 13CrMo4-5 (OD 48.3mm x 4.5mm) for a petrochemical furnace tube replacement in our Ludwigshafen facility. Kuaima handled the dual-grade order without confusion — separate MTCs, separate bundling, clear heat number markings on every tube. Dimensional tolerances were within EN specification. Delivery was 42 days, exactly as quoted. We will consolidate more of our boiler tube procurement through them going forward.

Anita Deshmukh

India

verified purchases

2025-06-08

Excellent Technical Support for T91 Grade Selection
We were specifying tubes for a new HRSG project operating at 540°C and 17 MPa. Kuaima's engineers recommended SA213 T91 over T22, explaining the creep rupture advantages and the potential for thinner wall design — which reduced our total tube weight by nearly 15%. Ordered 8 metric tons, OD 42.2mm x 5.6mm, cut to 7.5m lengths. Full UT per ASTM E213 and eddy current per E309 were performed. MTCs matched our third-party BV inspection perfectly. Response time on technical queries was under 12 hours every time.

Robert Callahan

United States

verified purchases

2025-06-30

Reliable Source for ASTM A192 Economizer Tubes
Purchased 12 tons of ASTM A192 seamless tubes in OD 38.1mm x 3.2mm for an economizer bank rebuild on a waste heat recovery boiler. Hydrostatic test certificates were included with every bundle and the surface finish — black varnished with end caps — arrived in perfect condition. Cut-to-length accuracy was within ±2mm, better than the ±3mm they promise. Our QC team verified tensile strength at 430 MPa, well above the 415 MPa minimum. Shipped from stock in just 9 days. This is exactly the kind of traceability and consistency we need for ASME code work.

James Whitfield

United Kingdom

verified purchases

2025-07-15

SA213 T22 Tubes Performed Flawlessly in Our Superheater Retrofit
We ordered 18 metric tons of SA213 T22 seamless boiler tubes, OD 51mm x 6.5mm WT, for a superheater replacement project on our 300MW coal-fired unit. Every tube came with EN 10204 3.1 MTC and the UT reports were clean — zero rejections during our incoming inspection. Wall thickness was consistently within ±7%, tighter than the ±10% we expected. Kuaima's technical team helped us confirm the correct grade for 565°C continuous service. Delivery took 38 days which was right on their quoted lead time. Genuinely impressed with the quality at mill-direct pricing.