Welding Neck Flange WN
The WN welding neck flange is a core connection fitting specially used for pipelines carrying high-temperature, high-pressure, flammable and explosive, and toxic media. It is mainly used for high-strength sealed butt connections between pipelines and pipelines, pipelines and equipment, and pipelines and valves. It adopts a tapered neck gradual transition structure, with full-penetration butt welding at the pipe end. The weld is full and can be inspected by non-destructive testing, eliminating hidden safety hazards in the weld. It can effectively disperse pipeline stress, buffer alternating temperature and pressure loads, and resist pipeline vibration, tensile and torsional deformation. It is mainly used for steam pipelines, oil and gas transportation, chemical processes, high-temperature and high-pressure fluids, and pipeline networks transporting toxic and corrosive media. It can be used for pressure pipeline special equipment, boiler supporting pipelines, and pressure vessel interface connections. It is the designated special flange product for all high-risk, high-pressure, and high-safety-level industrial pipeline projects.
Inquiry
- The biggest advantages of WN neck butt welding flanges are tapered neck stress relief, full penetration butt welding, non-destructive testing capability, and ultra-high safety level. Integrally forged and formed in one piece
- Dense metal structure with no defects
- Tapered long neck with smooth thickness transition
- Perfectly distributes concentrated pipe stress
- extremely strong resistance to fatigue, vibration, and thermal deformation. Precision beveled pipe end butt joint
Detailed Introduction
Welding neck flange (WN), commonly known as high-neck flange, is integrally forged and formed, with a long tapered transition neck, and is connected to the pipe by full-penetration butt welding through the neck bevel, which is different from the fillet weld connection of the slip-on flange. The tapered neck structure can smoothly disperse pipeline stress, and has strong resistance to fatigue, bending moment, and alternating temperature; the weld can undergo RT and UT non-destructive testing, and the welding quality is controllable. It is the preferred flange for high-temperature and high-pressure, flammable and explosive, and toxic medium working conditions. The product implements HG/T20592 (European standard PN system), HG/T20615 (American standard Class system), GB/T9115, ASME B16.5, and ASME B16.47 standards. The sealing surfaces cover RF, MFM, TG, RTJ, and other forms, among which RTJ is specially used for ultra-high-pressure working conditions. Materials cover carbon steel, alloy steel, stainless steel, and duplex steel. Pressure ratings are PN10~PN420/Class150~2500. It is widely used in pressure piping systems in petroleum, chemical, electric power, coal chemical, metallurgy, and other industries. We provide full-process customization services. You are welcome to provide detailed parameters to obtain an accurate quotation.
- Integrally forged, dense metal structure, smooth transition of the tapered neck effectively disperses stress
- Full-penetration butt welding connection, the weld can undergo UT/RT non-destructive testing, quality is controllable
- Suitable for harsh working conditions such as high temperature and high pressure, flammable and explosive, and toxic media
- Implements mainstream standards such as HG/T20592 and ASME B16.5, with diverse sealing surface forms
- Materials cover carbon steel, alloy steel, stainless steel, and duplex steel, and special materials can be customized
- Supports non-standard customization, including ultra-large diameter, high-pressure ratings, and special heat treatment
| Product Name | Weld Neck Flange WN |
| Product Categories | Contact us to confirm |
| Customization | Our factory has the full set of non-standard customization and OEM contract manufacturing capabilities for high-pressure high-end WN flanges, and can undertake differentiated orders for various harsh working conditions. Supports customization of ultra-large diameter, ultra-high-pressure rating, special thickened wall thickness, and long high-neck LWN non-standard flanges. Special materials such as A105, 16Mn, Cr5Mo, P11, P22, P91, 304, 316L, duplex steel, and Hastelloy can be customized. Supports customization of RTJ ring joint face, special hole spacing, non-standard thickness, and special heat treatment processes. Can perform mold-opening forging production according to American standard, European standard, German standard, and non-standard drawings. Supports laser marking of LOGO, batch number, standard, and material for OEM labeling, and customization of high-end export anti-rust packaging and engineering documents. Customization qualification rate is 100%, all non-destructive testing passed, suitable for full |
| MOQ | Our factory's WN welded neck flanges support flexible procurement modes, suitable for high-pressure engineering supplementary orders, samples for inspection, bulk centralized procurement, and foreign trade full-container orders. Conventional DN15-DN600 carbon steel standard pressure in-stock specifications have a minimum order of 1 piece, supporting scattered replenishment at construction sites, high-pressure pipeline network maintenance, and small-order procurement for engineering inspection. The MOQ for conventional engineering bulk procurement is 20 pieces, enjoying tiered wholesale |
| Lead Time | Our factory is equipped with large-scale fully automatic forging equipment, CNC precision machining, and non-destructive testing production lines. WN flange production capacity is stable and quality is controllable. Conventional PN16/PN25/PN40 carbon steel in-stock specifications for DN15-DN600 are shipped extremely fast within 24 hours, meeting the urgent material replenishment needs of high-pressure construction sites. Conventional medium and large diameters, RF/MFM sealing surfaces, and medium-high pressure specifications 3 |
| Packaging | WN welded neck flanges are high-end high-pressure precision pipe fittings, using heavy-industry-grade anti-rust and anti-vibration exclusive packaging. High-end anti-rust oil is sprayed at the factory to prevent oxidation and corrosion of high-temperature alloy and stainless steel materials. Sealing surfaces and bevels are all equipped with dedicated plastic protective covers to completely prevent bumps, scratches, deformation, and wear. Small and medium diameter products are individually wrapped with protective film and classified into thickened hard cardboard boxes; large diameter high-pressure flanges use waterproof stretch film and multi-layer woven wrapping, reinforced and packed on solid wood pallets. Each batch is accompanied by flaw detection reports, material spectrum reports, hydrostatic test reports, certificates of conformity, and factory documents. The outer packaging is marked with specifications, pressure, material, standard, and batch number information, moisture-proof, rust-proof, shock-proof, and pressure-resistant, fully suitable for domestic heavy-industry long-distance transportation and international sea freight container long-term stacked storage, |
| Reference Price | Inquiry |
| Standards | HG/T20592, HG/T20615, GB/T9115, ASME B16.5, ASME B16.47 |
Applications
- High-temperature steam pipe networks of thermal power plants, boiler main steam pipeline connections
- Petroleum refining and chemical process pipelines, long-distance high-pressure natural gas pipelines
- Coal chemical high-pressure reaction pipelines, metallurgical high-temperature equipment pipe networks
- Pressure vessel inlet and outlet, special equipment pipeline connections
- Foreign trade B2B export projects, requiring high-end engineering that complies with American standards and European standards
Overview
A welding neck flange (WN) is a high-strength flange whose tapered neck design can effectively distribute pipeline stress, and its full-penetration butt weld structure ensures reliable connection, with weld quality verifiable through non-destructive testing. It is especially suitable for harsh working conditions such as high temperature and high pressure, flammable and explosive media, and toxic media, and is a key connection component for pressure pipelines in fields such as petrochemicals, power, and coal chemicals. The WN flanges we produce strictly follow standards such as HG/T20592 and ASME B16.5, offer a variety of sealing faces and material options, and can be customized according to project requirements.
Key Features
Tapered neck transition design: smoothly distributes pipeline stress and enhances resistance to fatigue and alternating temperature changes. Full-penetration butt weld: the weld can undergo UT/RT inspection to ensure welding quality. Integral forging: the metal structure is dense with no internal defects. Multiple standards and sealing faces: meet different engineering requirements. Diverse materials: covering carbon steel to duplex steel, with custom special alloys available. Strict quality control: undergoes inspection such as flaw detection and hydrostatic testing before leaving the factory to ensure product reliability.
Applications
Suitable for high-temperature and high-pressure steam lines, petroleum refining process pipelines, long-distance natural gas transmission pipelines, coal chemical high-pressure pipelines, metallurgical high-temperature equipment, etc. Also used for pressure vessel connections, boiler pipelines, and other special equipment. In environments with frequent temperature and pressure fluctuations, strong pipeline vibration, or media with high-risk characteristics, WN flanges are the preferred choice for safe connections.
Specifications
Applicable standards include HG/T20592, HG/T20615, GB/T9115, and ASME B16.5/16.47. Pressure ratings cover PN10 to PN420, and Class150 to 2500. Sealing faces include RF, MFM, TG, RTJ, etc. Materials cover carbon steel, alloy steel, stainless steel, and duplex steel. Conventional sizes are DN15-DN600, and larger sizes can be customized. For specific parameters, please refer to the specification table or contact us for confirmation.
Purchase & Delivery
We support flexible procurement. Conventional carbon steel in-stock specifications have a minimum order quantity of 1 piece, and bulk orders enjoy discounts. Conventional specifications from DN15-DN600 are usually shipped within 24 hours, while the delivery time for non-standard customized products must be confirmed according to the specific specifications. All products use heavy-duty anti-rust packaging to ensure transportation safety. You are welcome to provide detailed specifications and quantities, and we will provide you with an accurate quotation and delivery time.
Service & Support
We provide a three-year warranty and lifetime technical support. Products undergo strict testing before leaving the factory to ensure quality. If non-human-caused quality problems occur, free replacement is provided. At the same time, we provide technical support such as selection guidance, welding process recommendations, and alignment with inspection standards. Our customer service team will provide one-on-one service to assist you in completing your purchase.
FAQ
What is the difference between WN flanges and SO flanges and PL flanges?
WN flanges (welding neck flanges) use a tapered neck transition and full-penetration butt welding, and are suitable for high temperature and high pressure and high-risk media, with welds that can be inspected; while SO (slip-on) and PL (plate flat welding) flanges are usually used for medium- and low-pressure room-temperature working conditions, have lower connection strength, and are not suitable for high-pressure pipelines of special equipment.
Under what working conditions must WN flanges be used?
In scenarios such as steam, oil and gas, toxic media, large pressure fluctuations, high explosion-proof requirements, and special equipment pressure piping, WN welding neck flanges must be used to ensure safe and reliable connections.
What is the maximum pressure rating of WN flanges?
We can produce ultra-high pressure specifications of PN420 (Class2500), meeting the needs of ultra-high temperature and ultra-high pressure working conditions. The specific pressure rating can be selected according to project requirements.
Can WN flanges pass non-destructive testing acceptance?
Our WN flanges are all forged, with a dense structure, and after welding can pass UT/RT non-destructive testing acceptance, ensuring weld quality.
Do you support foreign trade export?
Yes. We implement international standards such as American standards and European standards, have complete qualification documents, and can cooperate with global customs clearance and full-container export. Welcome to contact us for more export support information.
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