Weld Neck Flange

The Stainless steel weld neck flange (WNF) is a flange type which is generally used with pipes, as opposed to pressure vessels. The design of the flange allows for a full penetration weld at its base where it connects to the pipe. There are two types weld neck flanges which is regular and long. This weld can also be X-ray to inspect the quality and standard of product. ANSI B16.5 Weld Neck Flange are acceptable where high pressure, utmost temperatures, vibratory stresses and absolute impact apply. The abbreviation of Weld Neck is WN Flange which have implementation in industries that uses piping.

The design of weld neck include hub to reduce the stress at the base of the flange. Regular weld neck flanges are used with buttweld fittings and also for connecting two pieces of pipe together. Long weld neck flange are usually used with equipment and vessel nozzles. A long weld neck flange is rarely used with pipe. Both types of flanges are mainly drilled to match the inside diameter of the pipe or fitting to which it will be welded to. However, the inner diameter can be ground out to match the larger bore pipe, if the drill does not match.

The Welding neck flanges is normally referred to as the high hub flange. It is designed to transfer stresses to the pipe, thereby reducing high stress concentrations at the base of the flange. The weld neck flange is the best designed butt-welded flange of those currently available because of its inherent structural value. It is expensive than the other flanges because of its design.

ASME / ANSI B16.5 Weld Neck Flange Manufacturer In India

Devdeep Steel Alloys is a specialised manufacturers of high quality pipe Weld Neck flange available in standards ANSI B16.5 Flanges, ANSI B16.47 Series A & B, DIN Flange, JIS B2220 flange, MSS SP44 Flange, EN1092-1 FLANGES, API 605, AWWA C207 Flange, industrial pipe flanges in India. We quickly provide the standard size of stainless steel flanges and carbon steel flanges because of ready stock facility. ANSI B16.5 Weld Neck Steel flange have generally pressure ratings as follows. 150 lb, 300 lb, 400 lb, 600 lb, 900 lb, 1500 lb, 2500 lb. We also manufacture plate Weld Neck flanges from special nickel alloy steel grades. The material is provided within few working days in time programs.

Our Weld Neck pipe flange are available with face type of Flat Face (WNFF), Raised Face (WNRF) & Ring Type Joint (WNRTJ) and also with female threads. Steel Weld Neck flanges are also available with or without hub as per the requirement of customer. Devdeep Steel Alloys offer steel plate flanges to all companies coupled with various industries. For instance petrochemical plants, paper mills, power generation, pharmaceutical plants, oil refineries, shipbuilding, turnkey projects and waste water treatment plants among others.

Weld Neck pipe flanges are comparatively used where high & huge pressure applications are needed. To allow an easy access, in a piping system you should use Weld Neck steel flanges only one time when it is closed. At the present time we design Weld Neck flange with advance technology made from raw material of high quality, that have low maintenance. Moreover the products are available at very fair & competitive price.

Types Of Pipe Flange

Slip-on flange, weld neck flange, threaded flange, socket weld flange, blind flange, lap joint flange are the most common types of steel flanges. The special flanges such as orifice flanges, long weld neck flanges, spectacle flange to cater all industrial needs. In fact steel pipe flange are manufactured according to international quality standards which are available in various material, sizes & dimensions. In hazardous welding areas where the situation is extraordinary and areas are highly volatile. For that reason one can use our pipe flanges as an advantage in working those circumstances. Thereupon we timely deliver the products within stipulated time frame. High durability, corrosion resistance technique as well as dimensional accuracy are the advantages of our products. Our range of flanges consequently got approval in the global and the domestic markets

Carbon Steel / Stainless Steel Weld Neck Forged Flanges Production Range

Size: 1/2″ (15 NB) to 48″ (1200NB)

Standards: ANSI B16.5 Flanges, ANSI B16.47 Series A & B, DIN Flange, JIS B2220 flange, MSS SP44 Flange, EN1092-1 FLANGES, ASA, API 605, AWWA C207 Flange.

Pressure Ratings: Class 150, Class 300, Class 400, Class 600, Class 900, Class 1500, Class 2500. PN6, PN10, PN16, PN25, PN40, PN64 etc.

Carbon Steel Weld Neck Flanges: A350 LF1, LF2, LF3 CL1/CL2.

A694 F42, F46, F48, F50, F52, F56, F60, F65, F70, A516.60, 65, 70. Steel RST37.2, C22.8

Stainless Steel Weld Neck Flanges: ASTM A182 F202, F304/304L/304H, F316/316L, F316H, F316TI, F310, F321, F904L.

Alloy Steel Weld Neck Flanges: ASTM A182 F1, F5, F9, F11, F22, F91.

Nickel Alloy Weld Neck Flanges : Alloy C22, C276, A400, A600, A625, A800 & A825 / ASTM B462 Alloy 20.

Flange Face Type: Flat Face Flanges (FF), Raised Face Flange (RF), Groove and Tongue, Ring Type Joint (RTJ)

Coating/Surface Treatment: Oil Black Paint, Anti-rust Paint, Yellow Transparent, Cold and Hot Dip Galvanised, Zinc Plated.

Value Added Services: Customised Flanges & CNC Machining.


Ansi B16.5 weld neck flange dimension

OUTSIDE DIAMETER  ≤ 24 = 1.6 mm > 24 = ± 3.2 mm
DIAMETER HUB AT BASE ≤24 1.6 mm (0.06 in) >24 ±3.2 mm (±0.12 in)
INSIDE DIAMETER≤ 10 = ± 0.8 mm ≥ 12 = + 1.6 mm / – 0 mm ≥20 +3.2 mm / -1.6 mm
DIAMETER HUB AT POINT OF WELDING ≤5 +2.4 mm / -0.8 mm (±0.09 in / -0.03 in) ≥6 +4.0 mm / -0.8 mm (+0.15 in / -0.03 in)
DRILLING  Bolt Circle = 1.6 mm Bolt Hole Spacing = ± 0.8 mm
ECCENTRICITY OF BOLT CIRCLE ≤ 2½ = 0.8 mm max. ≥ 3 = 1.6 mm max.
THICKNESS ≤ 18 = + 3.2 mm / – 0 ≥ 20 = + 4.8 mm / – 0
LENGTH THRU HUB ≤ 18 = + 3.2 mm / – 0.8 mm ≥ 20 = + 4.8 mm / – 1.6 mm
DIAMETER OF CONTACT FACE 1.6 mm RF (0.06 in) ±0.8 mm (±0.03 in) 6.35 mm RF (0.25 in) ±0.4 mm (±0.01 in) Tongue & Groove ±0.4 mm (±0.01 in) Male-Female ±0.4 mm (±0.01 in)


  • Weld Neck Raised Face Flange
    • ANSI Class 150, B16.5, RF (in)
    • ANSI Class 300, B16.5, RF (in)
    • ANSI Class 400, B16.5, RF (in)
    • ANSI Class 600, B16.5, RF (in)
    • ANSI Class 900, B16.5, RF (in)
    • ANSI Class 1500, B16.5, RF (in)
    • ANSI Class 2500, B16.5, RF (in)
  • Weld Neck Ring Type Joint Flange
    • ANSI Class 150, B16.5, RTJ (in)
    • ANSI Class 300, B16.5, RTJ (in)
    • ANSI Class 400, B16.5, RTJ (in)
    • ANSI Class 600, B16.5, RTJ (in)
    • ANSI Class 900, B16.5, RTJ (in)
    • ANSI Class 1500, B16.5, RTJ (in)
    • ANSI Class 2500, B16.5, RTJ (in)


  • ANSI B16.47 Series A
    • ANSI Class 150, B16.47 Series A (in)
    • ANSI Class 300, B16.47 Series A (in)
    • ANSI Class 400, B16.47 Series A (in)
    • ANSI Class 600, B16.47 Series A (in)
    • ANSI Class 900, B16.47 Series A (in)
  • ANSI B16.47  Series B
    • ANSI Class 150, B16.47 Series B (in)
    • ANSI Class 300, B16.47 Series B (in)


  • ANSI Class 75, Industry Standard (For SOF) (in)
  • ANSI Class 75, Industry Standard (For WNF) (in)
  • ANSI Class 250, Industry Standard (in)
  • ANSI Class 350, Industry Standard (in)

Marking & Packaging

Steel Flange Marking & Packaging

We deliver Weld Neck flanges from our warehouse to your workplace with complete protection in the meantime. The unforeseen accidents can damage the product during delivery, therefore we pack them in wooden pallet. In case of exports, we use wooden cases for standard export packaging. We take great care of product during transportation and operation. To clarify details, we clearly label the products regarding quality, quantity and product I.D outside the package. To prevent damage during transportation, Devdeep cover the product in plastic bags and close them in cartoon boxes. Furthermore we also provide seaworthy wooden cases plywood boxes according to the requirement of customer.

The Weld Neck, WN Flanges contains marking such as Lot no, Steel Grade, outside diameter, Size & dimension, Wall thickness including Devdeep Steel Alloys Brand Mark. For customised marking you can contact us. We guarantee the fastest delivery for products in country, because of well equipped storage and warehouse facilities.

Quality Assurance & Test Certificates:

We undertake strict inspection at each stage in the process of production of Weld Neck flanges. At Devdeep Steel Alloys from purchasing of material to dispatch the product contains no defect. Our team member frequently examine the flange to confirm the international quality, codes and standards. ASTM, ASME (American), MSS, DIN German), EN (European), JIS (Japanese). To confirm the quality of products, to witness the dimension & material reports. We can call a certified Third Party Inspection agencies upon request. At Devdeep Steel Alloys, the clients can nominate Third Party Inspection for offered products. We can also arrange the TPI by World reputed Agencies like LLOYDS, DNV, ICB, Bureau Veritas and many other.

We use high quality raw material for manufacturing steel Weld Neck flange tested from approved NABL Lab. Other testing reports such as Non Destructive or destructive and Hydro Testing Reports can be provided upon request of customer,

Manufacturer Test Certificate (MTC) as per EN 10204 / 3.1B will be provided along with the ANSI B16.5 Weld Neck Flanges. In addition 100% Radiography Test Report, Raw Materials Certificate & Third Party Inspection Report available on demand.