What is Weld Neck Flange?
Weld neck flange is one type of flanges, which can be also called welding neck flange has a long tapered hub and round pipe transition to weld with the pipes or fittings. Weld neck flange is not easily deformed and has good performance sealing which widely has been used in many industries.
These flanges have advantages and disadvantages because of the design structures. Advantages: the connection is not easy to deform, good sealing effect and wide usage that can be specially applied for the pipelines with large fluctuations in temperature and pressure as well as the pipelines with high temperature, pressure and low temperature. It is also used for the pipelines to transport expensive media, flammable and explosive media, and poisonous gas.
Disadvantages: weld neck flanges have big volume and heavy weight compared with other types of flanges, which make the cost is high, installation and location is difficult, so these flanges are easily cracked during the transportation.
Weld neck flange is produced through the forging process, the materials can be carbon steel, alloy steel and stainless steel.
Carbon steel: A105, A350 LF2, C22.8, S355JR, etc.
Stainless steel: A182 F304/F304L/F316/F316L/F321 etc.
Alloy steel: F11, F12 etc.
Technical Specifications
The Weld neck flange has many sizes in different pressure levels. The following information is just about their sizes and tolerances.
The types of weld neck flanges according to standards
ASME Weld neck flange
Weld neck flange can be produced according to ASME B16.5. ASME B16.5 is the standard of the American Society of Mechanical Engineers. It is the most popular standard in the world for producing flanges. There are two types in ASME, B16.5 and B16.47. ASME B16.5 is for the diameter 1/2” to 24”. ASME A16.47 series A and B are for 24” to 60”
Weld neck flange DIN standard
Weld neck flange DIN standard. The DIN standard has almost been replaced by EN1092 but it is a very important standard for a very long time. There are many standard codes in DIN as per different pressures. It stipulates unified standards for products, such as quality, minimum performance, characteristics, dimensions, etc
Weld neck flange EN1092-1 standard
It is commonly used in European countries and is becoming more and more popular. In this standard weld neck flange is type 11 with many kinds of pressures and sealing face.
For welding neck flange the correct description should be EN1092 type 11 PN6/10/16/25/40/63/100 and sealing face type.
Classify weld neck flange according to material
The materials of weld neck flanges includes several types.Please see the below.
Types of weld neck flange as per sealing face
The sealing face of the weld neck involves RF(raised face), FF(plate face), RJ(ring joint), TG(tongue and groove), male and female(MFM) . The used pressure ranges of each type are a little different. Please see the below.
Socket Weld Flanges Applications
Welding neck flanges are widely used for the pipeline connections of petroleum & gas, petrochemical, water engineering, ship building, seawater cleaning, construction etc.
| Application industries | Functions |
| Pipeline system | Connection for the pipes and fittings in the pipeline system. |
| Industrial application | Apply to a variety of industries, such as petroleum and gas, chemical and power plants. |
| Thermal Engineering | Condenser, heat exchanger, engine blade. |
| Ship building | Operation pipes, Submersible, gas cylinder. |
| Sea engineering | Evaporator, heat exchanger, exchanger, oil production platform, oil cooler. |
| Chemical industry | late heat exchanger, plate condenser, cooling tower, chlorination tank. |
| Aerospace | Engine, fan plate, gas compressor blade, frame, hatch cover, tail. |
| High pressure and high temperature applications | Weld neck flanges can be applied to high pressure and temperature environments because of their strength and durability. |
Quality Assurance
1) Weld neck flanges are available in carbon steel and stainless steel. Our company purchases raw materials from well-known domestic steel mills and conducts chemical analysis and testing on the raw materials.
2) During the flange production process, the blanking stage is strictly controlled, and the blanking data is within or above the standard. So that there will be no problems during the production process.
3) All products will undergo non-destructive testing after production is completed, and no random inspection will be performed. If necessary, BV and SGS testing can be performed.
4) After the inspections, apply anti-rust oil to ensure that the products will be not rust during transportation and use.
5) Packaging method: wooden pallet + plastic wrap. Wooden boxes can be used for packaging if required by the customer.