Q235B Carbon Steel Flange

Tianjin Shunchen Industrial is a leading steel fitting manufacturer with 12 years of export experience, specializing in standard and custom carbon steel flange products. Our Tianjin production base is equipped with fully automatic forging production lines and national-level physical & chemical testing laboratory, focusing on R&D and production of slip-on, weld neck, threaded and blind Q235B flanges matching municipal engineering, industrial factory, fire fighting and HVAC pipeline scenarios.

Different from rough cast flanges with unstable internal structure, our Q235B flanges adopt hot forging blank + full CNC finish machining technology, with standardized grain refinement treatment. Our QC supervisor with 11 years of pressure component inspection experience carries out full-process tracking inspection for each batch, ensuring flatness deviation ≤0.03mm, bolt hole position tolerance ≤0.1mm and impact energy ≥27J at room temperature. All products comply with GB, ASME, EN and JIS standards, and can provide complete mill test certificates (MTC EN 10204 3.1) and third-party SGS inspection reports.

Real-world Performance Testing

1. Hydraulic Pressure Burst Test (Third-party SGS Test)

Test Standard: GB/T 13927, ASME B16.5

Test Conditions: Gradual water pressure boost, room temperature

Test Samples: Ordinary cast carbon flange, Small factory forged flange, Our Q235B forged flange

Key Findings:

Ordinary cast flange: Burst at 1.6 times rated PN16 pressure with internal shrinkage cavity leakage

Common forged flange: Minor sealing surface deformation at 2.2 times rated pressure

Our Q235B forged flange: No deformation or leakage at 3.0 times PN16 rated pressure, safety margin improved by 87%

2. Low-temperature Impact & Weldability Verification

Tested under standard construction ambient temperature, core performance indicators as follows:

Q235B forging blank: Yield strength ≥235MPa, tensile strength 375–460MPa, Charpy impact value ≥27J at 20℃

Good low-carbon composition without hard brittle phase, no welding crack after full penetration welding test

Integrated forging eliminates casting pores, avoiding hidden leakage risks under long-term alternating pressure

3. Neutral Salt Spray Corrosion Resistance Test

Test Standard: ASTM B117

Test Conditions: 5% neutral salt spray continuous spraying

Test Results:

Uncoated black forged flange: Red rust appears after 280 hours

Anti-rust oil treated flange: No obvious rust after 800 hours

Hot-dip galvanized Q235B flange: No rust or zinc layer peeling after 2200 hours, suitable coastal humid pipeline projects

Real-world User Scenarios & Verified Cases

Case 1 Municipal Water Supply Pipeline Renovation Project (Vietnam Urban Water Group)

Industry: Municipal infrastructure

Problem: Original cast flanges often leak at pipe joints under long-term water pressure, frequent excavation maintenance causing traffic interruption and high after-sales cost.

Solution: Adopt PN16 RF slip-on Q235B carbon steel flanges with anti-rust oil surface treatment, DN50–DN600 full range matching.

Result: After 6 years underground buried operation, zero joint leakage failure, pipeline maintenance frequency reduced by 83%. Annual purchase volume reaches 980 tons, 6-year continuous strategic cooperation.

Case 2 Factory Fire Protection & Cooling Water Pipeline Project (Shandong Heavy Industry Park)

Industry: Industrial factory supporting pipeline

Problem: Purchased low-precision flanges have inconsistent bolt hole spacing, difficult on-site assembly, low construction efficiency and many rework links.

Solution: Custom standard Q235B threaded & slip-on flanges, full CNC one-time hole drilling with unified dimensional tolerance.

Result: On-site assembly efficiency increased by 70%, rework rate dropped from 10.5% to 0.8%, fully designated flange supplier for the park’s phase II & III factory construction.

Case 3 General Chemical Low-pressure Medium Pipeline Project (Jiangsu Light Chemical Plant)

Industry: Light chemical production

Problem: Ordinary flanges crack after long-term alternating temperature change, medium leakage causes production shutdown and safety hazards.

Solution: Weld neck Q235B forged flanges with normalized grain refinement treatment, customized hot galvanizing anti-corrosion.

Result: After 5 years continuous production operation, no flange cracking or medium leakage, annual production shutdown loss saved over 2.4 million RMB.

Authentic Customer Reviews

"Our municipal buried water pipelines run year-round under constant pressure. Your Q235B forged flanges have stable size and zero leakage, greatly cutting our pipeline maintenance workload."

—— Nguyen Minh, Procurement Manager, Vietnam Urban Water Group

"All factory fire and cooling water systems use your carbon flanges. Precise bolt hole positioning saves a lot of installation time, stable batch quality and complete test documents for project acceptance."

—— Liu Wei, Infrastructure Director, Shandong Heavy Industry Park

"Low-temperature alternating workshop environment puts high demands on flange toughness. Your normalized Q235B forgings avoid cracking risks, our chemical production line runs safely all year round."

—— Zhang Tao, Equipment Supervisor, Jiangsu Light Chemical Plant

Verified Product Parameters

(1) General Execution Standards

(2) Core Technical Parameters

(3) Chemical Composition (wt%)

(4) Mechanical Properties

Core Advantages

1. Authoritative Test Data Fully Traceable: All hydraulic burst, impact and salt spray test data come from SGS third-party labs and long-term pipeline project verification, complete test reports provided for engineering filing.

2. Integrated Forging & Precise Machining: No casting pores or shrinkage cavities; full CNC machining ensures sealing flatness, effectively eliminating pipeline medium leakage risks.

3. Excellent Weldability & Low-temperature Toughness: Controlled Q235B carbon equivalent avoids welding cold cracks, suitable indoor and outdoor ambient temperature pipeline systems.

4. Diversified Types & Anti-corrosion Options: Multiple flange structures and pressure grades optional, galvanized coating available for coastal salt fog and humid working conditions.

5. Complete Qualifications & Stable Spot Supply: ISO9001:2015 certified, full set of export customs clearance documents; massive standard flange stock supports 3–7 days fast delivery.

Suitable For

· Municipal Engineering: Urban water supply, drainage, sewage treatment, municipal fire protection main pipelines

· Industrial Factory: Factory cooling water, compressed air, fire sprinkler, HVAC circulating pipeline systems

· Light Chemical Industry: Low-pressure neutral medium conveying, production auxiliary pipeline connections

· Construction Engineering: Building fire piping, underground garage water supply and drainage systems

· Agriculture & Irrigation: Large farm irrigation main pipeline flange connections

· General Machinery: Equipment cooling cycle water, hydraulic auxiliary pipeline fittings

Why Choose Tianjin Shunchen?

Looking for leak-proof, low-cost Q235B carbon steel flanges for municipal and industrial pipeline projects? Choose Tianjin Shunchen Industrial, a professional forged flange manufacturer with 12 years global export experience, products widely adopted in overseas municipal and factory pipeline projects.

We maintain thousands of tons standard flange spot inventory all year round. Our professional technical team recommends flange type, pressure rating and anti-corrosion scheme according to your pipeline medium and environment. Factory direct sales without intermediate dealers, competitive unit price and consistent batch dimensional accuracy. Contact us now to get free samples and detailed quotations!

Real Product & Shipment Gallery

Production & Quality Inspection

Fully automatic hot forging production line

CNC precision turning & drilling machine

Universal tensile & impact testing machine

Hydraulic pressure burst test bench

Product Display

PN16 RF slip-on Q235B carbon flange

WN weld neck galvanized carbon steel flange

Threaded small-diameter fire protection flange

Large DN1200 blind forged flange

Shipment & Packaging

Standard export packaging: Anti-rust paper + plastic film + wooden case fixed with steel strips

Custom customer logo wooden box packaging available

Container loading standard: 20ft container ≈20 tons; 40ft container ≈42 tons

Complete shipment documents: Bill of lading, commercial invoice, MTC, third-party SGS inspection report

Customer Application Scenarios

Vietnam municipal water supply pipeline project

Shandong industrial park fire cooling pipeline project

Jiangsu light chemical production piping project

Domestic urban fire protection supporting project

Popular Tags

Q235B carbon steel flange, forged carbon flange, slip on flange, weld neck flange, threaded flange, pipeline flange, municipal pipe fitting, China flange manufacturer

Related Categories

Galvanized Steel Coil, Color Coated Steel Coil, Q235B Flat Plate, Steel Pipe, Steel Elbow, Steel Tee, Steel Reducer, Checkered Plate