Pipe Flange Production Process

Flange production process

The production process is mainly divided into four types: forging, casting, cutting, and rolling.

Cast and Forged Pipe Flanges

The cast pipe flange has an accurate blank shape and size, a small processing amount, and low cost, but has casting defects (pores, cracks, inclusions); the internal structure of the casting is poorly streamlined (if it is a cutting part, the streamlined form is even worse); forged flanges generally, the carbon content is lower than that of the cast pipe flange, and it is not easy to rust. The forging has a good streamlined shape, and a relatively dense structure, and its mechanical properties are better than that of the cast pipe flange; if the forging process is improper, there will be large or uneven grains, hardening cracks, and the cost of forging is higher than that of casting pipe flange. Forgings can withstand higher shear and tensile forces than castings. The advantage of castings is that they can produce more complex shapes, and the cost is relatively low; the advantage of forgings is that the internal structure is uniform, and there are no harmful defects such as pores and inclusions in castings; the difference between cast pipe flanges and forged flanges from the production process, For example, the centrifugal flange is a kind of casting pipe flange. Centrifugal flange belongs to the production flange of the precision casting method. Compared with ordinary sand casting, the structure of this kind of casting is much thinner, the quality is much improved, and it is not easy to have problems such as loose structure, pores, and trachoma.

First of all, we need to understand how centrifugal pipe flanges are produced, the process and products of centrifugal casting flat welding flanges, which are characterized in that the products are processed through the following process steps:

①Put the selected raw material steel into an intermediate frequency electric furnace for melting, so that the temperature of molten steel reaches 1600-1700°C;

②Preheat the metal mold to 800-900°C to maintain a constant temperature;

③Start the centrifuge, inject the molten steel in step ① into the preheated metal mold in step ②;

④The casting is naturally cooled to 800-900°C for 1-10 minutes;

⑤ Cool with water to close to normal temperature, demold, and take out the casting.

Pipe Flanges  in Mongolia

Let's learn about the production process of forged flanges:

The forging process generally consists of the following processes, that is, selecting high-quality billets for blanking, heating, forming, and cooling after forging. Forging methods include free forging, die forging, and membrane forging. During production, different forging methods are selected according to the quality of forgings and the number of production batches.

Free forging has low productivity and a large machining allowance, but the tools are simple and versatile, so it is widely used for forging single-piece and small-batch forgings with relatively simple shapes. Free forging equipment includes air hammers, steam-air hammers, hydraulic presses, etc., which are suitable for the production of the small, medium, and large forgings. Die forging has high productivity, simple operation, and easy mechanization and automation. Die forgings have high dimensional accuracy, a small machining allowance, and a more reasonable fiber structure distribution of forgings, which can further improve the service life of parts.

The full name of die forging is model forging, and the heated blank is placed in the forging die fixed on the die forging equipment for forging.

In layman's terms, forged pipe flanges are better in quality, generally produced by die forging, have a fine crystal structure, and high strength, and of course are more expensive.

Both cast flanges and forged flanges are commonly used manufacturing methods for flanges. Depending on the strength requirements of the parts to be used, if the requirements are not high, turning flanges can also be used.

3. Cutting the pipe flange

Cut out the inner and outer diameter and thickness discs of the pipe flange directly on the middle plate, and then process the bolt holes and waterline. The flange produced in this way is called a cut flange, and the maximum diameter of this type of flange is limited to the width of the middle plate.

4. Rolled pipe flange

The process of cutting a strip with a middle plate and then rolling it into a circle is called rolling, and it is mostly used in the production of some large flanges. After the rolling is successful, it is welded, then flattened, and then the waterline and bolt holes are processed.

Flanges & PVC Flanges in Mongolia

Pipe Flanges are parts that are connected to each other between pipes and are used for connection between pipe ends; they are also useful for flanges on equipment inlets and outlets, And can be used as connection between two equipments, example reducer flanges. Flange connection or flange joint refers back to the detachable connection of flange, Gasket and bolt as a team of combined sealing structure. Pipe flange refers back to the flange used for piping in the pipeline installation, And used on the equipment refers to the inlet and outlet flange of the equipment. There are holes in the flange, and the bolts tightly connect the two flanges.

The pipe flanges are sealed with gaskets. Flanges are divided into threaded (screw connection) flange fittings, welding flanges and clip flanges. Flange fittings are usually employed in pairs, very poor-work pipes can use wire flanges and welding flange fittings with pressures greater than 4 kg. Add sealing points within the two flanges, immediately after tighten with bolts. Pipe Flanges with different pressures have different thicknesses, and the bolts they use are also different. When the water pump and valve are connected to the pipeline, some parts of these equipments are also made into corresponding flange shapes, also called flange connection. All connecting parts that are closed at the same time by using bolts around the two planes are generally called "flanges". For example, the connection of ventilation pipes, such parts can be called "flange parts". But this connection is only a part of the equipment, Such as the text between the flange and the pump, it is not easy to call the pump 'flange parts'. Smaller ones such like valves Wait, always be called 'flange parts'.

The reducer flange is used for the connection between the motor and the reducer, as well as the connection between the reducer and other equipment.

PVC Flange Fittings in Mongolia

Related types of flanges

Flat welding flange

Flat welding flanges include plate flat welding flanges and necked flat welding flanges.

Plate Flat Welding Flange (PL)

The flat welding flange is suitable for the connection of steel pipelines with a nominal pressure not exceeding 2.5MPa. The sealing surface of the flat welding flange can be made into three types: smooth, concave-convex, and tongue-and-groove. The application of the soft flat welding flange is the largest. It is mainly used when the medium conditions are relatively mild, such as low-pressure non-purified compressed air and low-pressure circulating water.

Flat Weld Neck Flange (SO)

The neck height of the flat welding flange with the neck is lower, which improves the rigidity and bearing capacity of the flange. Compared with butt welding flanges, the welding workload is large, the consumption of welding rods is high, and it cannot withstand high temperature and high pressure, repeated bending, and temperature fluctuations, but it is more convenient to install on-site, and the process of slapping and rubbing the welding seam can be omitted, which is more popular.

Folded neck butt welding (WN)

Butt Weld Flanges: Welded neck flanges are often referred to as "high pivot" flanges. Its purpose is to transfer pressure to the piping, thereby reducing high-stress concentrations in the flange base. Neck flange welds are the best design butt welds that provide flanges due to their inherent structural value. However, the price is relatively high, because the product's production process is complicated.

Threaded (Threaded) Flange: The threaded flange is connected with a thread. But the center of the product has the thread size corresponding to the tube. Its main advantage is that it can be assembled without soldering.

Sliding Flanges: Sliding flanges have a lower pivot because the pipe enters the single flange before welding. It is welded inside and outside to provide enough strength to prevent leakage. Sliding flanges are bored to match slightly larger OD pipes. They are superior to weld neck flanges for many users due to the lower initial cost, but the final installation cost will probably not be as much as the increase in weld neck flanges.

Lap Flange: The Lap Flange is the same slip flange, except that it is one radius between the hole and the flange race. The radius must have flanges to accommodate lap stub ends. Typically, lap flanges and lap stubs mate together at the end of the assembly system.

The socket weld flange is a similar slip flange, except it has a hole and counter hole size. The matching of the counter hole with the pipe allows the pipe to be inserted into the flange similar to the sliding flange. The diameter of the smaller hole is the same as the ID to match the same pipe. The confinement is a built-in hole that acts as a shoulder sleeve designed for piping to stay at the bottom. This eliminates any flow restriction when using socket weld flanges.