Complaint
Weld neck flange (WN flange) has a neck that can relocated stress of the pipe, so to reduce the pressure that gathered in the flange bottom.
Material: Carbon, Alloy and Stainless Steel
Standards: ASTM A105, ASTM A182
Sizes: 1/2'' to 24'', Customized up to 48''
Thickness: Schedule 10(S) to SCH 160
Pressure Ratings: Class 150 to 2500
Face Type: RF, RTJ
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.
It is compatible to the pipelines that works in high or low temperature and bear high pressure. Specially for the pipe or the valves when PN is larger than 2.5 Mpa.
Welding neck flange have two forms (shapes), one with reducing neck as we called reducing weld neck flange; One with a even diameter of typical long neck named as long neck weld flange.
Reducing Weld Neck Flange
As it's name it is like a combination of pipe reducer and flange, so it could be welded to a smaller pipe directly.
Long Weld Neck Flange
Simplified called as LWN flange, the neck part seems like a elongated pipe and connected to a flange. So in most cases it works as a nozzle for a column or a barrel.
You can choose for a normal thickness long welding neck flange or a heavy LWN flange that with bigger thickness and a differently shape.
Face Type
Like other flanges it has Raised Face (RF) Type and Ring Type Joint (RTJ).
Raised Face Weld Neck Flange
RTJ Weld Neck Flange
| Class | Flat Face | Raised Face | Ring Type Joint |
| ANSI 150 | WN Flange ANSI 150 FF (in) | WN Flange ANSI 150 RF (in) | WN Flange ANSI 150 RTJ (in) |
| ANSI 300 | WN Flange ANSI 300 FF (in) | WN Flange ANSI 300 RF (in) | WN Flange ANSI 300 RTJ (in) |
| ANSI 400 | WN Flange ANSI 400 FF (in) | WN Flange ANSI 400 RF (in) | WN Flange ANSI 400 RTJ (in) |
| ANSI 600 | WN Flange ANSI 600 FF (in) | WN Flange ANSI 600 RF (in) | WN Flange ANSI 600 RTJ (in) |
| ANSI 900 | WN Flange ANSI 900 FF (in) | WN Flange ANSI 900 RF (in) | WN Flange ANSI 900 RTJ (in) |
| ANSI 1500 | WN Flange ANSI 1500 FF (in) | WN Flange ANSI 1500 RF (in) | WN Flange ANSI 1500 RTJ (in) |
| ANSI 2500 | WN Flange ANSI 2500 FF (in) | WN Flange ANSI 2500 RF (in) | WN Flange ANSI 2500 RTJ (in) |
The datasheets we have on this site are shown below. For simplicity sake, only datasheets that adhere to B16.5 are shown. ASME B16.5 covers flange dimensions from ½" to 24". For sizes larger than this, please visit our flange datasheets page.
The three most common types of facings for weld neck flanges are:
Take the measurements of the following:
A: Hub Diameter at Point of Weld
B: Weld Neck Bore
C: Thickness
Y: Length through Hub
O: Outside Diameter
R: OD of Raised Face
X: Diameter at Base of Hub
Pipe flanges are manufactured in all the different materials like stainless steel, cast iron, aluminium, brass, bronze, plastic etc. but the most used material is forged carbon steel and have machined surfaces.
Flanges are welded to pipe and equipment nozzle. Accordingly, it is manufactured from the following materials;
The list of materials used in manufacturing is covered in ASME B16.5 & B16.47.
Commonly used Forged material grads are
| Material | Fittings | Flanges | Valves | Bolts & Nuts |
| Carbon Steel | A234 Gr WPA | A105 | A216 Gr WCB | A193 Gr B7 A194 Gr 2H |
| A234 Gr WPB | A105 | A216 Gr WCB | ||
| A234 Gr WPC | A105 | A216 Gr WCB | ||
| Carbon Steel Alloy High-Temp | A234 Gr WP1 | A182 Gr F1 | A217 Gr WC1 | A193 Gr B7 A194 Gr 2H |
| A234 Gr WP11 | A182 Gr F11 | A217 Gr WC6 | ||
| A234 Gr WP12 | A182 Gr F12 | A217 Gr WC6 | ||
| A234 Gr WP22 | A182 Gr F22 | A217 Gr WC9 | ||
| A234 Gr WP5 | A182 Gr F5 | A217 Gr C5 | ||
| A234 Gr WP9 | A182 Gr F9 | A217 Gr C12 | ||
| Carbon Steel Alloy Low-Temp | A420 Gr WPL6 | A350 Gr LF2 | A352 Gr LCB | A320 Gr L7 A194 Gr 7 |
| A420 Gr WPL3 | A350 Gr LF3 | A352 Gr LC3 | ||
| Austenitic Stainless Steel | A403 Gr WP304 | A182 Gr F304 | A182 Gr F304 | A193 Gr B8 A194 Gr 8 |
| A403 Gr WP316 | A182 Gr F316 | A182 Gr F316 | ||
| A403 Gr WP321 | A182 Gr F321 | A182 Gr F321 | ||
| A403 Gr WP347 | A182 Gr F347 | A182 Gr F347 |
ASTM standards define the specific manufacturing process of the material and determine the exact chemical composition of pipes, fittings and flanges, through percentages of the permitted quantities of carbon, magnesium, nickel, etc., and are indicated by "Grade".
The usual materials of flanges include stainless steel, carbon steel, aluminum and plastic. The choice of the material largely depends on the purpose of the flange. For example, stainless steel is more durable and is necessary for heavy use. On the other hand, plastic is more feasible for use in the home because of its reasonable price and easy installation. The materials used for flanges are under the designation of the American Society of Mechanical Engineers.
Pipe Flange Standards mainly include three systems in the world, ANSI/ASME flange system(American), DIN flange system(European system), JIS flange system, other system made according to this three systems, like GB flange standard, which mainly made according to ANSI/ASME and DIN flange standard, Duwa Piping supplies those flanges with top quality and soonest delivery time.
The most frequently asked questions regarding flanges and flange fittings have to do with how flanges fit on specific steel tube and steel pipe ends.
Flanges are used to connect pipes or other equipment components in various industries, and they come in a variety of materials and sizes. Flange material standards are developed by standard-setting organizations and describe the properties and characteristics of different materials that can be used to make flanges. Some examples of commonly used flange material standards include:
The choice of flange material standard will depend on various factors such as the application, the environment, the fluid being transported, and the required performance characteristics. For example, high-pressure applications may require flanges made from materials with high strength and durability, while corrosive environments may require flanges made from materials with good resistance to corrosion.
Flange Inspection
Before dispatching from manufacture each flange is inspected to ensure quality. During an inspection you have to check the following;
ASME B16.5 and B16.47 standards cover permissible tolerances for inspection.
ASME B16.5 and B16.47 standards cover permissible tolerances for inspection.
Because of the normal wooden boxes or wooden pallets have to do fumigation treatment, we usually use plywood pallet or plywood case or box to pack steel flanges without fumigation treatment.
A flange is a method of connecting pipes, valves, pumps, and other equipment to form a piping system. It also provides easy access for cleaning, inspection, or modification.
When a piping joint requires to be dismantled, flanges are being used. These are primarily used on equipment, valves, and specialty items. Breakout flanges are provided at predetermined intervals in certain pipelines where maintenance is a regular occurrence. The flanges, gaskets, and bolting make up a flanged joint, which is made up of three separate but interconnected components. To achieve a leak-proof joint, special controls are required in the selection and application of all of these elements.
Here are the details of Flanges about their advantages and their applications.
