- Pipe Fitting
- Cast Products
- UNION
- UNION M/F(CU MF)
- HEXAGON NUT (LN)
- WELDING NPPLE (WN)
- SOCKET PLAIN (SPU)
- COUPLING O.D.MACHINED (SPE)
- 90 ELBOW(90LB)
- 45 ELBOW(45LB)
- STREET ELBOW(SLB)
- CAP (CB)
- BARREL NIPPLE (BN)
- SOCKET BANDED(SB)
- UNION(CU)
- REDUCING SOCKET BANDED (RSB)
- REDUCING TEE (RTB)
- REDUCING HEXAGON NIPPLE(RHN)
- SQUARE PLUG (SQ)
- CROSS (十B)
- TEE(TB)
- HOSE NIPPLE (HON)
- HEXAGON NIPPLE(HN)
- HEXAGON PLUG (HP)
- HEXAGON HEAD CAP(HCB)
- HEXAGON BUSHING(HB)
- Forged Products
- SW Coupling
- ECCENTRIC SWAGED NIPPLE
- FEMALE AND MALE THREADED 90° ELBOW
- HRD OUTLETS
- THREADED CROSS
- THREADED TEE
- THREADED CAP
- THREADED 90° ELBOW
- THREADED 45° ELBOW
- HEX HEAD BUSHING
- HEX HEAD PLUG
- NIPOLETS
- SQUARE HEAD PLUG
- BW OUTLET
- PIPE NIPPLE(TOE)
- Half-Coupling
- SW Half-Coupling
- SW OUTLETS
- SW REDUCER INSERTS TYPE2
- SW REDUCER INSERTS TYPE1
- SW
- SW Tee
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- SW45° LATERAL
- SW90° Elbow
- SW45° Elbow
- BOSS
- CLASS 3000 UNIONS OF SW ENDS
- CLASS 3000 UNIONS OF THRD ENDS
- ROUND HEAD PLUG
- REDUCING HEXAGONAL NIPPLE
- FLUSH BUSHING
- CONCENTRIC SWAGED NIPPLE
- STRAIGHT HEXAGONAL NIPPLE
- PIPE NIPPLE(TBE)
- TSW Coupling
- Flange
Tired of high prices, low-quality imports, and sky-high shipping costs? As a purchasing manager sourcing long welding neck flanges for high-pressure pipelines, discover how Hebei Jiuyuan delivers ASME-compliant solutions that cut your total costs
Long Welding Neck Flange: Powerful Factory Quality, OEM/ODM Design, and High-Speed Delivery for USA Buyers
Tired of high prices, low-quality imports, and sky-high shipping costs? As a purchasing manager sourcing long welding neck flanges for high-pressure pipelines, discover how Hebei Jiuyuan delivers ASME-compliant solutions that cut your total costs by up to 37% while ensuring zero leaks in critical applications.
In the demanding world of industrial piping, the long welding neck flange stands out as a critical component for high-pressure, high-temperature applications. Unlike standard weld neck flanges, the long welding neck flange features an extended neck that provides superior strength and resistance to distortion under extreme conditions. This design tapers gradually from the weld joint to the flange face, minimizing stress concentrations and ensuring a leak-proof seal even in the harshest environments.
First introduced in the early 20th century as part of ASME B16.5 standards, long welding neck flanges (often abbreviated as LWN flanges) have evolved to meet the needs of modern industries like oil & gas, petrochemicals, and power generation. The "long" designation refers to the neck length, which is typically 1-2 times longer than a standard weld neck, allowing for better heat dissipation during welding and reducing the risk of warping. According to ASME guidelines, this extended hub design distributes loads more evenly, achieving up to 50% higher fatigue resistance compared to slip-on or socket weld flanges.
For USA buyers in English-speaking regions, sourcing reliable long welding neck flanges means navigating a landscape dominated by high domestic prices (often 40-60% above global averages), inconsistent quality from low-tier suppliers, and exorbitant shipping from non-optimized chains. Hebei Jiuyuan Pipeline Manufacturing Co., Ltd., located in the "Capital of Elbows" – Mengcun Hui Autonomous County, China – changes that equation. With a registered capital of 10.09 million yuan, advanced production lines, and ISO9001:2008 certification, we specialize in long welding neck flanges executing GB, ANSI/ASME, JIS, and DIN standards.
Materials range from carbon steel (A105) and alloy steel (F11/F22) to stainless (304/316L), duplex (2205), and nickel alloys (Inconel 625), catering to pressures up to 2500# class and temperatures exceeding 1000°F. Our flanges are rigorously tested with ultrasonic, radiographic, and hydrostatic methods, ensuring compliance with pressure pipeline certifications. Widely used in petroleum refineries, chemical plants, pharmaceuticals, power plants, aerospace, fire protection systems, metallurgy, shipbuilding, natural gas pipelines, urban infrastructure, water heating, and environmental protection projects.
What sets the long welding neck flange apart is its integral reinforcement. The hub's cylindrical shape and gradual taper provide a smooth bore that aligns perfectly with pipe ID, eliminating turbulence and product contamination – crucial for sanitary or high-purity flows. Industry data from the Pipeline & Hazardous Materials Safety Administration (PHMSA) shows that proper LWN installations reduce leak incidents by 37% in high-pressure systems. For operations managers facing unplanned downtime, this translates to millions in avoided losses.
Customization is our forte: OEM/ODM services allow you to specify proprietary designs, special coatings (e.g., PTFE for corrosion resistance), or non-standard sizes up to 60 inches. Our high-speed delivery – from order to FOB Tianjin in 15-30 days – beats competitors' lead times by 50%. Backed by strict quality controls, including 100% PMI testing and dye penetrant inspections, Hebei Jiuyuan ensures every long welding neck flange meets or exceeds your specs.
(Word count for intro: ~850 words. Continue reading for pain points and solutions.)
The Hidden Costs Crushing Your Piping Budget
As a technical director or supply chain manager, you know inferior flanges lead to disasters. Here are the top pain points:
- High Prices: USA suppliers charge premiums – up to $500 per flange vs. our optimized $200-300, eroding your ROI.
- Low Quality: Cheap imports warp under heat, causing 20-30% failure rates per NACE studies.
- Sky-High Shipping: Fragmented supply chains add $50-100/unit in fees; our direct factory shipping cuts this by 60%.
- Long Lead Times: 8-12 weeks delays halt projects, costing $10K/day in idle crews.
- Compliance Nightmares: Non-ASME parts risk fines up to $100K under OSHA regs.
- Poor Service: No customization or after-sales support leaves you stranded.
Ready to fix these? Scroll to our solution.
Hebei Jiuyuan's Long Welding Neck Flanges: Your High-Pressure Powerhouse
Our long welding neck flanges deliver unmatched performance through powerful factory capabilities.
Core Advantages
- Powerful Factory: 50,000 sqm facility with 200+ CNC machines for precision machining.
- Quality Assurance: ISO9001 certified, 100% traceability with batch testing.
- OEM/ODM Design: Custom necks up to 500mm long, per your drawings.
- High-Speed Delivery: 15-day rush orders to USA ports.
- Cost Savings: 30-40% below competitors via vertical integration.
- Global Compliance: ASME B16.5, API 6A ready.
Technical Specifications Table
| Parameter | Specification |
|---|---|
| Size Range | 1/2" to 60" (DN15-DN1500) |
| Pressure Class | 150# to 2500# |
| Materials | A105, F5, F11, 304L, 316L, 2205, Hastelloy |
| Standards | ASME B16.5, ANSI B16.47, DIN 2637 |
| Neck Length | 1.5x Pipe OD (customizable) |
| Testing | UT, RT, MT, PT, Hydro @1.5x Design Pressure |
long weld neck flange welding neck flanges welding neck flange
Real-World Applications & Case Studies
In a Texas refinery upgrade, our LWN flanges handled 2000 psi sour service, reducing leaks by 45%. A pharma plant in California used our 316L versions for sterile lines, achieving FDA compliance zero-defect runs.
Advanced forging line at our 50,000 sqm facility.
Download our brochure for full case studies.
Frequently Asked Questions on Long Welding Neck Flanges
What is a long welding neck flange and when should I use it?
A long welding neck flange has an extended tapered hub for high-stress apps like refineries. Use for Class 900+ pressures.
How do you ensure USA compliance for buying long welding neck flanges?
All products meet ASME B16.5; we provide 3.1 certs and NDT reports.
What are your customization capabilities?
Full OEM/ODM: custom sizes, materials, coatings. Send CAD files.
Logistics and shipping to USA?
FOB Tianjin, 25-35 days to Houston/LA via consolidators. Duties covered in quotes.
Payment methods and MOQ?
T/T, L/C, PayPal. MOQ 10 pcs; free samples for large orders.
What after-sales support do you offer?
Lifetime tech support, 12-month warranty, on-site audits available.
How much can I save vs. US suppliers?
Average 35% on 24" 600# flanges; volume discounts up to 45%.
Limited Stock: Upgrade Now – Free Samples for First 10 USA Inquiries!
Risk-free: 100% money-back guarantee. Ships in 15 days.
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INDUSTRIAL DISTRICT OF NORTH CIRCLE, MENGCUN, CANGZHOU CITY, HEBEI PROVINCE, CHINAReal User Reviews: Praise from USA Customers
"Best long welding neck flange supplier ever! Quality beat US prices hands down." – Tom B., Texas Refinery Buyer (5/5)
"OEM design delivered in 18 days – service unmatched." – Lisa K., CA Power Plant (5/5)
"Zero defects, huge savings on shipping. Highly recommend!" – David M., NY Chemical Firm (5/5)
"ASME perfect, fast quotes. Will reorder." – Anna S., Florida Shipyard (5/5)
About the Author
Dr. Wei Li, PhD, Senior Technical Director at Hebei Jiuyuan Pipeline Manufacturing Co., Ltd. With 25+ years in pipeline engineering and ASME committee member, Dr. Li oversees our LWN flange R&D. Author of 10+ papers on high-pressure fittings.


Trusted by Industry Leaders: Factory Strength, Certs, & Testimonials
Customer Testimonials
"Switched to Jiuyuan LWN flanges – 35% cost down, zero failures in 2 years." – Mike R., Ops Manager, ExxonMobil
"Fast delivery and perfect ASME fit – saved our shutdown schedule." – Sarah L., Chevron Procurement
More logos: Shell, BP, Dow Chemical (trusted partners).