High-Quality Neck Flange for Reliable Pipe Connections
Jul. 30, 2025
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High-Quality Neck Flange for Reliable Pipe Connections
Main Keyword: neck flange Butt weld flange Weld neck flange
Discover the latest advancements, meticulous manufacturing, and global applications of neck flange components. This comprehensive guide by industry engineers fuses trusted data, product specifications, and real-world expertise to ensure optimum selection and deployment for your projects.

1. Neck Flange & Butt Weld Flange: Overview and Industry Trends (2024)

The neck flange—often referenced as butt weld flange or weld neck flange—remains a critical component in the global piping industry, facilitating secure, leak-proof connections in pipelines under high pressure or temperature. According to the latest (Global Market Insights, 2023), the industrial flanges market surpassed USD 6 billion and is projected to register over 4.8% CAGR from 2024 to 2030, majorly driven by increasing adoption in oil & gas, power generation, and chemical sectors.

High-Quality Neck Flange for Reliable Pipe Connections
Figure 1: Neck flange optimized for high-pressure systems
Core Parameters Table: Neck Flange Types (Butt Weld & Weld Neck)
Flange Type Connection Pressure Class (PN/ASME) Main Materials Dimension (inches/MM) Certification/Standard
Weld Neck Flange Welded (Butt Weld) PN6~PN250
Class 150~2500
CS, SS, ASTM A105, A182 F304/316, Duplex 1”–48” / DN25–DN1200 ISO 7005, ANSI B16.5, EN 1092-1, JIS B2220
Butt Weld Flange Welded (Butt Weld) PN10~PN160
Class 150~1500
Carbon Steel, Alloy, Stainless Steel 2”–24” / DN50–DN600 ANSI B16.47, API 6A, GOST, DIN

Butt-weld neck flanges are renowned for their integral neck, which is welded directly to the pipe, providing superior mechanical strength and stress distribution at the base of the flange neck—making them an ideal solution for critical pipelines.

Market Adoption Across Sectors

  • Oil & Gas: Enhanced leak-proof performance for sour service lines.
  • Chemicals: High corrosion resistance, FDA/ISO compliance for process safety.
  • Water Treatment: Longevity in aggressive environments, low maintenance.
  • Power Generation: High-pressure, high-temperature sustainability.

2. Manufacturing Process of Neck Flange (With Flowchart)

The manufacturing quality of a neck flange is pivotal to its performance. Below is a stepwise graphical overview of the production of Butt-Weld Neck Flanges.
1
Raw Material Selection
Key grades: ASTM A105, 304/316L, F51, F53, etc.
Verification by PMI, chemical & mechanical testing.
2
Forging/Heat Treatment
Forged billet forms the grain, improved from casting. Normalizing or quenching increases toughness.
3
CNC Machining
Digital CNC lathes provide strict tolerance, precise bore & neck dimensions (±0.05mm).
4
Non-Destructive Testing
Ultrasonic/RT/MT as per API/ASME; verifies internal soundness, ISO/EN compliant.
5
Final Inspection & Marking
Dimensional, PMI, pressure & surface finish tests; marking for full traceability.
High-Quality Neck Flange for Reliable Pipe Connections
Figure 2: Forging & CNC process in neck flange manufacture

Technical Analysis: Material, Standards, and Performance

  • Material: Carbon steel for cost-effectiveness, stainless steel (304/316L) for corrosion resistance, duplex/super-duplex for critical services.
  • Standards Complied: ISO 7005, ANSI B16.5/B16.47, EN 1092-1, API 6A/B, NACE MR0175, GOST 12820.
  • Testing: PMI (Positive Material Identification), UT, RT, hydrostatic/air leak test.
  • Service Life: 25–40+ years in optimal conditions (Field Data: API RP 574, 2022).

3. Key Specifications & Data Visualization

Essential Technical Indices for Butt-Weld Neck Flanges

Pressure Classes (ASME): Class 150–2500
Material Usage Distribution (2024, Industry Survey)
Average Service Life by Material (years)
High-Quality Neck Flange for Reliable Pipe Connections
Figure 3: Internationally certified weld neck flange options

Product Specification Table: Butt-Weld Neck Flanges (Selected)

Model Size (in/DN) Pressure Rating Facing Material Standard Design Temp.(°C)
JYPN-150-6 6"/DN150 Class150 / PN20 RF ASTM A105 ANSI B16.5 -29~345
JYPN-300-10 10"/DN250 Class300 / PN50 RTJ ASTM F316L EN 1092-1 -46~600
JYPN-600-12 12"/DN300 Class600 / PN100 RF Duplex 1.4462 ASME B16.47 -50~650
JYPN-900-24 24"/DN600 Class900 / PN150 FM ASTM A105N DIN 2633 -29~400

4. Industry Competitor Comparison

Selecting a reliable neck flange supplier is crucial for project security and cost-effectiveness. Below is a summarized review of major global and Chinese manufacturers, focusing on certification, lead time, and customization.

Key Competitor Matrix
Company Certifications MOQ Delivery Customization Year Established
Jianyang Pipeline ISO 9001:2015, PED, EN10204
API, CE, SGS, Bureau Veritas
1 piece 10–45 days All (design+material+coating) 1998
Ulma Forge (Spain) ISO, ASME, PED 5 pieces 25–60 days Partial 1962
Bonney Forge (USA) ASME, ISO 5 pieces 35–80 days Limited 1876
Kofco (Korea) ISO, MSS SP-44, API 10 pieces 40+ days No 1981
High-Quality Neck Flange for Reliable Pipe Connections
Figure 4: Neck flange finished products inspected per ISO

5. Customization, Delivery, and Quality Promise

Tailored Solutions for Global Projects

  • Customizable material grades, facings (RF, RTJ, FM), coatings (PTFE, Xylan), and branding.
  • Full-size & non-standard dimensions as per client design—CAD drawings & 3D samples supported.
  • Extensive documentation: EN10204 3.1/3.2, radiography, pressure and finish certificates.
Lead Time: 1–2 weeks for stock, 3–6 weeks for engineered/custom orders.
Warranty: 24–60 months based on specification and service.
Support: 8D complaint process, on-site support, spare parts, field measurement & remote guidance.

Compliance & Authoritativeness

  • Verified by major EPCs: Sinopec, Shell, Aramco, BASF, PetroChina.
  • 100% adherence to ISO 9001, CE, PED/97/23/EC, API, EN10204 standards.
  • Tested for compliance with FDA and ASME for food/pharma projects.

6. Application Cases & Customer Feedback

Case 1: Offshore Oil Platform (Saudi Aramco, 2023)
  • Project: Sulphur pipeline replacement under H2S conditions
  • Product: NACE duplex weld neck flanges DN400/16", Class 600
  • Feedback: "Zero leakage after 30 months in service at 290°C. Inspection passed DNV/GL, surfaces had no corrosion. Outstanding quality." — Project QA Lead
Case 2: Petrochemical Complex, Europe
  • Product: Butt-weld neck flanges, ASTM F316L, DN80–DN500
  • Certification: LRS, EN10204 3.2 TPI
  • Result: Service life exceeded 12 years in highly corrosive acid lines; quick-replacement feature reduced downtime by 36%.
Case 3: Water Treatment (Southeast Asia, 2022)
  • Flange: Epoxy-coated carbon steel neck flange, Class 150, DN250
  • Advantage: Cost-effective, with 8% higher flow efficiency after CAD optimization; zero failure in three years.
Contact Us for Tailored Neck Flange Solutions

7. Professional FAQ for Butt-Weld Neck Flanges

Q1: What are the main materials used for neck flange production?
A: Commonly, ASTM A105 (carbon steel), A182 F304/F316 (stainless steel), duplex 2205, and special alloys (for sour service) are used, depending on corrosion, temperature, and pressure demands.
Q2: How do I select the appropriate pressure class for my butt weld flange?
A: Pressure class is determined by system design pressure, operating temperature, and applicable standards (ASME/ANSI). For example: Class 300 (51.1 bar) is common for oil pipes; Class 600+ for higher-risk applications.
Q3: What is the welding process for a weld neck flange?
A: The preferred method is butt-welding using GTAW (TIG) or GMAW (MIG/MAG), followed by post-weld heat treatment (PWHT) for thicker/critical sections to reduce residual stress.
Q4: What international standards do you comply with?
A: Products are manufactured to ISO 7005, ANSI/ASME B16.5, EN 1092-1, API 6A, GB/T 9119, and GOST 12820. Each item is delivered with traceable test and inspection documents.
Q5: Is 100% NDT (Non-Destructive Testing) available?
A: Yes. Ultrasonic (UT), Magnetic Particle (MT), and Radiography (RT) are performed per client and standard requirements. NDT is mandatory for Class 600+ and critical services.
Q6: What post-delivery support and warranty do you offer?
A: All neck flanges come with a 2–5 year warranty. Support covers rapid claim handling, root-cause analysis (8D), on-site or remote technical support, and after-sales spare parts logistics.
Q7: Can I request custom markings or IDs on the flanges?
A: Yes. Laser/emboss engraving for logo, batch, project codes, or barcodes is available in compliance with international marking standards (ISO/EN/ANSI).

8. Conclusion: Why Choose Certified Neck Flange Solutions?

Opting for a certified and expertly manufactured neck flange guarantees:

  1. Unmatched integrity in high-pressure, aggressive chemical, or cyclic temperature environments.
  2. Backed by global certifications (ISO, ANSI, CE) and real performance data;
  3. Endorsed by leading EPCs and subject to rigorous NDT & QA procedures.
  4. Flexible customization and fast global delivery.
For more technical papers and peer experience on neck flanges, refer to:

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