Weldneck Flange
What is Weld neck Flanges?
Weld neck pipe flanges are connected to the pipe by welding the pipe to the neck of the pipe flange, which helps to pass on the stress from the weld neck to the pipe itself. This also reduces high stress concentration at the base of the hub of the weld neck pipe flanges. Weld neck pipe flanges are generally used in high pressure applications, where hot or cold temperatures exist. The inside diameter of a weld neck pipe flange is machined to match the inside diameter of the pipe.
Greenline Pipe & fitting offers weld neck pipe flanges manufactured at our facility to companies in various industries including shipbuilding, power generation, petrochemical plants, oil refineries, waste water treatment plants, paper mills, pharmaceutical plants and turnkey projects among others.We are an ISO 9001:2008,ISO 9001-2008, ISO 14001-2004, OHSAS 18001-2007, NSIC-CRISIL, EEPC, and QA-UKAS (ISO 9001-2008), SSI Certified company that follows total Quality Management System. and have been recognized as one of the world’s leading stockists and manufacturer of quality metals for over two decades and are committed to quick responses, unsurpassed quality, competitive pricing, reliable deliveries and an exhaustive inventory.
Weld neck Flange Specification
| Type | Weld neck Flange |
| Standards | ANSI B16.5, ANSI B16.47 Series A & B, MSS SP44, ASA, API-605, AWWA, Custom Drawings |
| Outside Diameter | ≤ 24 = 1.6 mm > 24 = ±3.2 mm |
| Inside Diameter | ≤ 10 = ±0.8 mm 12 thru 18 = 1.6 mm ≥ 20 = +3.2 mm / -1.6 mm |
| Diameter Contact Face | 1.6 mm RF = ±0.8 mm 6.35 mm RF = ±0.4 mm Tongue & Groove = ±0.4 mm Male-Female = ±0.4 mm |
| Diameter Hub at Base | ≤24 = 1.6 mm >24 = ±3.2 mm |
| Diameter Hub at Point of Welding | ≤ 5 = +2.4 mm / -0.8 mm ≥ 6 = +4.0 mm / -0.8 mm |
| Outside Diameter | ≤24 = 1.6 mm, >24 = ±3.2 mm |
| Drilling | Bolt Circle = 1.6 mm Bolt Hole Spacing = ±0.8 mm Eccentricity Bolt Circle with Respect to Facing ≤2.1/2 = 0.8 mm max ≥3 = 1.6 mm max |
| Thickness | ≤18 = +3.2 mm / -0 ≥20 = +4.8 mm / -0 |
| Length thru Hub | ≤10 = 1.6 mm ≥12 = ±3.2 mm |
| Pressure Ratings: | Class 150, Class 300, Class 400, Class 600, Class 900, Class1500, Class 2500 | PN6, PN10, PN16, PN25, PN40, PN64 etc. |
| Order | Accept custom order |
| Quality Assurance | All fittings and flanges are subject to strict inspection at each stage of the production process, from starting material purchasing to product dispatch. They are visually examined for conformity to ASTM, ASME, MSS, DIN, EN, and JIS codes and standards. Upon request, official certified Inspection Agencies can be called in to witness the material reports, dimensions and quality conformity of products. |
| Marking & Packing | Products are packaged to ensure that there is no damage during transit. In case of exports, standard export packaging is done in wooden cases. All buttweld fittings are marked with Grade, Lot No, Size, Degree and our trade mark. On special requests we can also, make custom marking on our products.#Protected by End Caps. |
| Value Added Services |
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| Test Certificates | Manufacturer Test Certificate as per EN 10204 / 3.1B, Raw Materials Certificate, 100% Radiography Test Report, Third Party Inspection Report |
Welding Neck Flanges are easy to recognize at the long tapered hub that goes gradually over to the wall thickness from a pipe or fitting. The long tapered hub provides an important reinforcement for use in several applications involving high pressure, sub-zero and / or elevated temperatures. The smooth transition from flange thickness to pipe or fitting wall thickness affected by the taper is extremely beneficial, under conditions of repeated bending, caused by line expansion or other variable forces.
Weld neck pipe flanges are connected to the pipe by welding the pipe to the neck of the pipe flange, which helps to pass on the stress from the weld neck to the pipe itself. This also reduces high stress concentration at the base of the hub of the weld neck pipe flanges. Weld neck pipe flanges are generally used in high pressure applications, where hot or cold temperatures exist. The inside diameter of a weld neck pipe flange is machined to match the inside diameter of the pipe.
These flanges are bored to match the inside diameter of the mating pipe or fitting so there will be no restriction of product flow. This prevents turbulence at the joint and reduces erosion. They also provide excellent stress distribution through the tapered hub and are easily radio graphed for flaw detection. This flange type will be welded to a pipe or fitting with a single full penetration, V weld (Butt-weld).
| Carbon Steel Lap Joint Flanges: | ASTM A105/A105N, A350 LF1, LF2 CL1/CL2, LF3 CL1/CL2, A694 F42, F46, F48, F50, F52, F56, F60, F65, F70, A516.60, 65, 70 (Spectacle Blind Flange, Spacer Ring/Spade Flange), Steel RST37.2, C22.8 |
| Stainless Steel Lap Joint Flanges: | ASTM A182 F202, F304/304L/304H, F316/316L, F316H, F316TI, F310, F321, F904L |
| Alloy Steel Lap Joint Flanges: | ASTM A182 F1, F5, F9, F11, F22, F91 |
| Special Alloy Lap Joint Flanges: | Duplex, Super Duplex, Nickel Alloys |
| Flange Face Type: | Weld neck Flate Face (WNFF), Weld neck Raised Face (WNRF), Weld neck Ring Type Joint (WNRTJ) |
| Coating/Surface Treatment: | Anti-rust Paint, Oil Black Paint, Yellow Transparent, Zinc Plated, Cold and Hot Dip Galvanized |