Weld Neck Flanges
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Weld Neck Flanges
Stainless Steel Weld Neck Flanges
Stainless Steel Weld Neck Flanges are butt-welded directly to a pipe, using a long, tapered hub that blends smoothly into the pipe wall. This design reinforces the joint and keeps flow turbulence to a minimum, which is why weld neck flanges are the preferred choice for high-pressure, high-temperature and cyclic-loading pipelines.
Manufactured in SS 304, 304L, 316, 316L, 310, 321, 347 and 904L, our weld neck flanges combine excellent corrosion resistance with the strength needed for critical services such as chemical processing, power generation and offshore installations. Careful welding and heat treatment during manufacturing keep dimensional accuracy and mechanical properties consistent across every batch.
Weld Neck Flange Specification
Their distinctive protruding neck matches the wall thickness of the connecting pipe, making weld neck flanges suitable for the most severe service conditions.
| Material | Stainless Steel — SS 304, 304L, 316, 316L, 310, 321, 347, 904L |
|---|---|
| Application | High and medium-pressure pipe connections in demanding piping systems |
| Size Range | ½" NB to 36" NB (customized sizes up to 48" NB on request) |
| Thickness | Sch 10S to SCH 120 |
| Pressure Class | Class 150 (up to 24") · 300 (up to 20") · 600 (up to 20") · 900 (up to 16") · 1500 (up to 10") · 2500 (up to 8") |
| Standards | ASME B16.5, ASME B16.47 Series A & B, EN 1092-1, MSS SP44, BS 4504 |
| EN / DIN / JIS Ratings | EN 6–40 Bar · DIN PN6–PN64 · JIS 5K–63K |
| Face Types | Raised Face, Flat Face, Reducing, Orifice, RTJ |
| Production Technique | Forged, heat-treated and precision machined |
| Supporting Material | Gasket, ring joint and flange bolts |
| Coating | Anti-rust paint, zinc plated, black oil paint, yellow transparent, hot & cold dip galvanized |
| Test Certificates | EN 10204/3.1B, mill test certificate, radiography test report, third-party inspection report |
Types of Weld Neck Flanges
SS Weld Neck Flange
Stainless Steel Long Weld Neck Flange
LWNRF Flange
WNRF Flange
Welding Neck Flange
Weld Neck Pipe Flanges
Raised Face Weld Neck Flange
Flat Face Weld Neck Flange
Reducing Weld Neck Flange
Weld Neck Orifice Flange
RTJ Weld Neck Flange
Slip On Flange Welding
Long Welding Neck
3 Inch Weld Neck Flange
6 Inch Weld Neck Flange
Weld Neck Flange Material Grades
Beyond stainless steel, weld neck flanges are also manufactured in these materials and grade designations.
| Material | Grade Designation |
|---|---|
| Stainless Steel | ASTM/ASME A/SA182 F304, F304L, F316, F316L · A/SA351 CF8, CF3, CF8M, CF3M · DIN 1.4301, 1.4306, 1.4401, 1.4404, 1.4308, 1.4408, 1.4409 |
| Carbon Steel | ASTM/ASME A/SA105, A105N · A/SA216-WCB · ASTM A350 LF2/ASME SA350 · DIN 1.0402, 1.0460, 1.0619 · High-yield ASTM A694 (F52, F56, F60, F65, F70, F80) |
| Alloy Steel | ASTM A182/ASME SA182 F5, F9, F11, F12, F22, F91 |
| Duplex | S31803, S32205 · A182 Gr F51, F52, F53, F54, F55, F57, F59, F60, F61 |
| Super Duplex | S32750, S32760 · A182 Gr F51, F52, F53, F54, F55, F57, F59, F60, F61 |
| Nickel | ASTM B564/ASME SB564 · Nickel 200, 201, 205, 205LC |
| Monel | ASTM B564/ASME SB564 · Monel 400 (UNS N04400), Monel 500 (UNS N05500) |
| Inconel | ASTM B564/ASME SB564 · Inconel 600, 601, 625, 690, 718, 783, X750 |
| Incoloy | ASTM B564/ASME SB564 · Incoloy 800, 800H, 800HT (UNS N08800), 825 (UNS N08825), 925 |
| 254 SMO | ASTM A182/ASME SA182 · SMO 254 / 6Mo · UNS S31254 · DIN 1.4547 |
| Nimonic | Nimonic 75, 80A, 90 |
| Alloy 20 | ASTM B462/ASME SB462 · Carpenter 20 Alloy / Alloy 20Cb-3 |
| Titanium | ASTM B381/ASME SB381 · Titanium Gr. 1, 2, 4, 5, 7, 9, 12 |
| Copper Nickel | ASTM/ASME SB 61, 62, 151, 152 · Copper Nickel 90/10 (C70600), Cupro Nickel 70/30 (C71500), UNS C71640 |
| Copper | T1, T2 · C10100 – C71640 series alloys |
| Brass | 3602, 2604, H59, H62 |
| Aluminium | 5052, 6061, 6063, 2017, 7075 |
| Other Grades | Tin bronze, aluminium bronze, lead bronze |
Applications of Weld Neck Flanges
Industries and equipment that rely on weld neck flanges for critical connections.
- Specialty Chemicals
- Power Generation
- Condensers
- Chemical Equipment
- Gas Processing
- Pulp & Paper Industry
- Sea Water Equipment
- Pharmaceutical Equipment
- Offshore Oil Drilling
- Petrochemicals
- Heat Exchangers
Dimension & Weight Charts
Full ANSI/ASME B16.5 dimension and weight tables for Class 150 through Class 2500 are published on our Dimensions page as reference charts, to keep hundreds of rows of figures free of transcription errors.
View Dimension ChartsQuality Testing & Value-Added Services
Every weld neck flange is checked before it leaves our facility.
- Chemical / Spectro Analysis
- Intergranular Corrosion (IGC) Test
- Hardness Test
- Pitting Resistance Test
- Positive Material Identification (PMI)
- Micro & Macro Structure Test
- Flattening Test
- Mechanical Testing (Tensile & Area)
- Hydrostatic Pressure Test
- Ultrasonic Flaw Detection
- Radiography (X-Ray) Test
- Magnetic Particle Inspection
Weld Neck Flange Symbol
The standard drawing symbol used to represent a weld neck flange on piping and instrumentation diagrams (P&IDs).
Frequently Asked Questions
What is a Stainless Steel Weld Neck Flange?
It is a flange with a long, tapered hub that is butt-welded to a pipe, giving a smooth, reinforced connection for high-pressure and high-temperature piping systems.
What sizes and pressure classes are available?
We manufacture sizes from ½" NB to 36" NB (customized up to 48" NB) across pressure classes 150 to 2500.
Which standards do these flanges follow?
ASME B16.5, ASME B16.47 (Series A & B), EN 1092-1, MSS SP44 and BS 4504, depending on the size and pressure class required.
Which face types are offered?
Raised Face (RF), Flat Face (FF), Reducing, Orifice and Ring Type Joint (RTJ) weld neck flanges are all available.
What quality checks are performed before dispatch?
Every batch undergoes PMI testing, hardness testing, hydro testing and dimensional inspection, along with mill test certificates as per EN 10204/3.1B.
Need a Quote on Weld Neck Flanges?
Share your size, grade and pressure class requirement and our team will get back to you with pricing and availability.