In order to make the insulated flange better operation, we must carry out assembly in accordance with the corresponding assembly needs, and at the same time, we should pay attention to matters, so as to ensure that the insulated flange can better serve us.

Precautions for insulation flanges

Among the components of the insulation flange, the insulation pad should have excellent oil resistance and aging resistance, and at the same time, it should also have better elasticity and impact toughness, so as to better ensure the performance of the insulation flange.

In addition, the insulation flange should have sufficient strength, so as to ensure that there will be no distortion when tightening.

At the same time, the appearance of the insulation seal should be ensured that it is cleaned and smooth, and the dirt and rust on it should be removed and clean when assembled.

In the general concept, the welded connection is a permanent connection and the bolted connection is a non-permanent removable connection, and the welded connection of the insulated joint is more reliable than the bolted connection of the insulated flange.

To ensure the performance of the insulating flange and its role, it is necessary to ensure the quality of the insulating flange, when used, it must be used in accordance with the conventional way and its principle, in accordance with the conventional assembly standards to carry out assembly, in accordance with the conventional operation methods to carry out use, only to do these aspects, can ensure that the insulating flange can be routinely operated.

The components of the insulation flange I introduced so much, if you want to know more about the insulation flange knowledge, you can always consult me, I in accordance with the timely answer for you.

Xiaobian I remind you again, when using the insulation flange must be in accordance with the needs, so as to ensure that the insulation flange better serve us.

A slip-on flange is a type of pipe flange that is slipped over the end of a pipe and welded in place.
A weld neck flange is a type of pipe flange that has a neck that is welded to the pipe.
Slip-on flanges are typically used for low-pressure applications, while weld neck flanges are used for high-pressure applications.
Slip-on flanges are easier to install than weld-neck flanges, but weld-neck flanges provide a stronger connection.
Weldneck Flanges are easier to align than Slip-on-flanges during the welding process because the centre of the bore of a Weldneck Flange is in alignment with the centerline of the connected pipe, while the bore of a Slip-on Flange is not in alignment with the centerline of the connected pipe.

Weld Neck Flange (WNF):

A weld neck flange is very similar in shape to a slip-on flange but has a much longer neck that extends outwards from the base of the fitting. The extended neck allows it to be securely welded onto the end of a pipe or tube, creating a stronger connection than with a SOF. This makes WNFs ideal for applications where extra strength is needed, such as those involving high pressure or vibration. Additionally, WNFs are usually more expensive than SOFs due to their increased complexity in manufacturing and installation.

Slip-On Flange (SOF):

A slip-on flange consists of a circular fitting that slips over the end of a pipe or tube. It is secured in place by welding the SOF to the outside of the pipe or tube. Slip-on flanges are easy to install and are cost-effective compared to other types of flanges. However, they are not as strong as weld neck flanges, making them less suitable for applications where high pressure or vibration could be an issue.

Below is the list of steel products to cancel the export tax rebate, and red parts are the related our products, steel pipes, pipe fittings and flanges.

Weld neck flange is the same diameter and wall thickness of the joint end as the pipe to be welded, just as the two pipes are welded. Slip on flange is a concave platform at the interface which is slightly larger than the outside diameter of the pipe. The pipe is inserted and welded inside. Butt welding has better welding performance and less corrosion.

1.Flat welding and butt welding are welding methods when flanges and pipes are connected. When welding slip on flanges, only one side welding is required, and the inner joints of welded pipes and flanges are not required. The welding of the weld neck flanges requires double side welding. Therefore, flat welding flanges are generally used for low and medium pressure pipelines, butt weld flanges are used for medium and high pressure pipelines. Butt weld flanges are generally at least PN2.5 MPa. Butt welding is used to reduce stress concentration. The welding flange is mostly a neck flange and also a nipple flange. Therefore, the installation cost of the welding flange, labor costs and auxiliary materials costs are higher, because there is more than one process.
2.Weld neck flange and slip on flange are the two most commonly used flanges. The weld neck flange is necked and the slip on flange is not. If it is for safety reasons, it is best to use weld neck flange. If it is normal medium and the pressure is not high, slio on flanges can be considered to use.
3.The weld neck flange is more expensive than the slip on flange, and is more susceptible to bumping during transport due to its shape.

We are a manufacturer of carbon steel flanges and have 36 years of experience in the production of carbon steel flanges. For our products, every production process has undergone rigorous inspection. For the raw material carbon steel flange blanks we purchase, Has the following advantages:

(1) All raw materials are made of standard billet, and our carbon steel flange blank material is stable and reliable;
(2), the flatness and ovality of the blank can be precisely controlled to minimize the processing volume;
(3) The processing precision of the blank is high, and the processing efficiency of the flange blank machine is increased by 50%;
(4), the finished product rate is high, the blank expansion ratio of the hot-expanded flange blank carbon steel flange reaches 1.25-1.35;
(5) The newly developed convex flange blank product saves about 24% of raw materials compared with the traditional process;
(6), energy saving, new technology of carbon steel flange blank compared with the traditional process, the production of per ton of flange, stamping flange blank wafer manufacturers can save 60% of coal consumption, shaped stamping parts carbon steel flange blank power consumption 40%;
(7), can be adjusted according to customer requirements.

ANSI B16.5 steel pipe flanges:
Pipe flanges also called flange plate. It is a very important accessary between pipes connection. ANSI B16.5 flanges are also used for the connecting between two equipments such as pipelines with valves or equipment.
Why choose pipe flanges connecting in the pipeline system?
In the pipelines two pipes can be welded together directly. But when there is a problem happened in the connection area, it will be difficult to be repaired. The same problem also occurs the connection between the pipe and valve. The above problem can be easily solved if flanged connection used in pipes or valves.
What components should be included in steel pipe flanged connecting?
The type of flange connection usually has two parts, gasket and bolt nuts (the pipe is welded to the flange first, then the valve and other equipment are mounted on the flange by bolts.) When connecting these parts, putting the gasket between the two flanges and tighten the bolts to make the two steel pipe flanges connected tightly together. In the case of piping maintenance, we can remove bolts from the flanges, take away the pipes or valves need to be repaired, and replace the new pipes and valves. In short, flanged connection makes the pipeline maintenance very convenient, flexible, and less effort.

Above mentioned information is just about the working process of ANSI B16.5 steel pipe flanges. ANSI B16.5 steel pipe flanges including many types, welding neck, slip on, blind, threaded, socket, lap joint and so on. Welding neck, slip on, and blind are the most usually used three types. Following let us share some features about them.
Welding neck flanges:
The neck of the welding neck flange can be welded directly to the pipe end. The welding neck flange has the specialities of convenient structure, high strength and good sealing performance. It is widely applied in different pressure piping specially high pressure.

Slip on flanges:
Slip on flange is short of SO flange. By inserting the pipe into the inner bore of the flange, the flange bore is slightly larger than the outer diameter of the pipe, and can be connected by a lap weld connection part at the top and bottom of the flange. The common sealing face type of slip on flange refers to RF, and FF. The feature of slip on flange is that the low cost, but the welding process is more complex than welding neck flange. It is usually used for middle and low pressure pipeline.

Blind flange:
Blind flange is a round disc only have bolt holes. It is generally used at the end of pipes to stop the flows just like the pipe cap.

Before we know why do forging flanges need heat treatment, we must first understand what the forgings are. Forging is the use of hand hammer, forging hammer or pressure equipment on the mold on the heating of the metal blank force, so that metal materials under the condition of non-separation plastic deformation, in order to obtain properties, size and performance meet the requirements of parts.

Then why should the forged flange be heat treated after forging? Its main purpose is to refine the coarse grains, eliminate the work hardening and residual stress, reduce the hardness, improve the cutting performance, prevent the white spots in the forging, and ensure the required metal structure and machinery. Performance to prepare for final heat treatment. Now let’s talk about several forms of heat treatment.

1. Normalizing
Forging flanges heat treatment first step: Normalizing.
It is to heat the forgings above the transformation temperature, forming a single austenite structure, after a period of uniform temperature stability, after the blast furnace air cooling, the main purpose is to refine the grain.
Normalizing temperature range is usually between 760 and 950 degrees centigrade, depending on the phase transition point of different component content. Generally, the lower the carbon and alloy content is, the higher the normalizing temperature is, the lower it is.

2. Tempering
Forging flanges heat treatment first step: Tempering.
The main purpose of tempering is to expand hydrogen. It can also stabilize the microstructure after phase transformation, eliminate the transformation stress and reduce the hardness, so that the forgings can be easily processed without deformation.
There are three kinds of tempering temperature, high temperature tempering, medium tempering and low temperature tempering. Among them, the tempering temperature at high temperature is 500 – 600, the tempering temperature at medium temperature is 350 – 490, and the tempering temperature at low temperature is 150 – 250.
The cooling rate after tempering should be slow enough to prevent whitening due to excessive transient stress during cooling and to minimize residual stress in forgings.

Forging flange materials are mainly steel materials, and less ferrous metals. It has three forms: rolling material, forging flange material and ingot. Rolling and forging materials are often used in medium and small forgings, and ingots are often used as raw materials for large free forgings. The materials for forging flanges include two main categories: carbon steel and alloy steel.

1. Carbon steel
Carbon steel is an iron-carbon alloy containing less than 2.11% carbon and a small amount of silicon (Si), manganese (Mn), sulfur (S), phosphorus (P) and other impurities, commonly known as carbon steel. It is widely used in manufacturing machinery parts, tools and equipment. At present, the output of carbon steel accounts for more than 90% of the total output of world steel.
There are three methods to classify carbon steel for forging flange: low carbon steel (<0.25%), medium carbon steel and high carbon steel (>0.60%), according to the carbon content of steel; common quality steel, high quality steel and high quality steel according to the content of harmful elements sulfur S and phosphorus P in the quality of steel; carbon structure steel (common carbon structure steel) according to the use of steel. Steel, high quality carbon structural steel and carbon tool steel (general purpose carbon tool steel and high quality carbon tool steel).
Brand of Forged Flange Carbon Steel: High Quality Carbon Structural Steel Name: Named according to the amount of carbon content in such steel. Steel with manganese content less than 0.8% is represented by a value of 10,000 times the carbon content, and steel with manganese content more than 0.8% is represented by “Mn” element after the carbon content.

2. Alloy steel
Alloy steel is to improve the comprehensive mechanical properties of steel, improve the technological properties of steel, or in order to obtain some special properties, on the basis of carbon steel, purposefully add a certain amount of alloy elements and steel grades. These alloying elements include titanium, vanadium, nickel, tungsten, molybdenum, silicon, aluminum, boron and rare earth elements.
Classification of alloy steels for forging flanges: Alloy structural steels (structural steels for engineering and machine building), Alloy tool steels (alloy tool steels, alloy measuring steels, cold working die steels, hot working die steels, plastic die steels, high speed tool steels) and special steels (stainless steel, heat resistant steels, abrasion resistant steels) According to the alloy content, the steel can be divided into low alloy steel, medium alloy steel and high alloy steel; according to the microstructure classification, the steel can be divided into hypoeutectoid steel, eutectoid steel, hypereutectoid steel, ledeburite steel and pearlite steel, bainite steel, martensite steel and austenite steel.

Forging flanges alloy steel grades: alloy elements are indicated by chemical element symbols in grades. When the average content of an element in steel is 1.5% – – 2.49% or 2.5% – – 3.49%, the symbolic digit of the element is 2 or 3, if the content is higher, and so on. Carbon content of alloy steel is numerically indicated: alloy structural steel is marked with two digits representing ten thousand times of average carbon content in front of the steel number. Alloy tool steels are marked in front of the steel number with one digit representing a thousandfold of the average carbon content. When the average carbon content is more than 1.0%, there is no need to mark the carbon content. High speed tool steels generally do not contain carbon content.

There are many kinds of carbon steel materials for manufacturing this product, so the material selection for the raw materials for manufacturing carbon steel flanges is very wide. There are four main aspects in the technical process that need to be mainly used in the production process. One is to carry out the forging process, one is to carry out the casting process, and the other is to use the middle plate for rolling. The fourth is to cut it into the middle plate. In the production process, the manufacturing cost of each process is also different, among which the cost required for the forging process is the highest, the middle plate manufacturing is the second, and the lowest cost  is the cast product. The old saying is good, cheap is not good, good goods are not cheap, this sentence is more appropriate here, because the quality and cost of the products manufactured by these processes are also proportional, the higher the cost of manufacturing The quality of its products will also be higher, and the lower the cost, the worse the quality of the products produced. The most common application of carbon steel flanges is in the connection of pipes, but we always have a doubt that is why carbon steel flanges are often used in pipe joint work? This is because carbon steel flange has a great role in the connection work of the pipeline.

Let’s introduce the application of the carbon steel flange in the pipeline. Because carbon steel flanges have great flexibility and do not affect each other during operation, it is only necessary to open one of the steel pipes, and the other operations are normal according to the original plan. This special skill is because the carbon steel flange can reduce some sudden disasters to a minimum in a certain work, so that it is more suitable for the repair work of the pipeline. Because the pipeline is often connected by multiple channels, if one channel fails, it will affect the work of other channels. However, if a carbon steel flange is used, this will not happen in the specific operation. It will focus on the part of the situation that has already occurred, and it will not affect other aspects of work, which is why carbon steel flanges are often used in the connection of pipelines. Another obvious advantage is that the operation of the carbon steel flange is relatively simple. It is only necessary to tighten or unscrew the screw to complete the entire operation in a short time.

Flange is a disk-like part, in the boiler, pipeline engineering is the most common, flange is mainly used for pipe connection, which called carbon steel pipe flange. Carbon steel pipe flange specifications are as follow: slip on flange, plate flange, weld neck flange, threaded flange, socket flange, lap and joint flange.
In the need to connect the pipeline interface, the installation of a flange, low pressure pipe can use threaded flange, more than 4 kg the pressure of the use of welding flange. The two plates are sealed between the flanges and then fastened with bolts. Different pressure flanges have different thicknesses and different bolts. Pumps and valves, in connection with the pipeline, these equipment parts, also made of the corresponding flange shape, also known as flange connection. All the connected parts which are bolted and closed at the periphery of two planes are generally called “flanges”, such as the connection of the ventilation pipe, which can be called “Flange type parts”.
Carbon steel pipe flange specifications of types
1.Slip on Flange/Plate Flange
The most commonly used one of the flat welded flanges. The flange and the fixed form of the pipe, is the flange sleeve at the end of the pipe, welding Falanrico and external mouth, so that the flange fixed, the applicable nominal pressure of not more than 2.5MPa.

Carbon steel pipe flange specifications of slip on flange
Advantages: Easy to draw, easy to manufacture, low cost and widely used.
Disadvantages: poor rigidity, so it must not be used for supply and demand, flammable, explosive and higher vacuum requirements of the chemical process piping system and high, extremely hazardous occasions.
2.Welding Neck Flange
Welding Neck flange strength, not easy to deformation, good sealing performance, there are many forms of sealing surface, the applicable pressure range is very wide.

Carbon steel pipe flange specifications of welding neck flange
Advantages: The connection is not easy to deform, the sealing effect is good, the application is widespread, applies to the temperature or the pressure large fluctuation the pipeline or the high temperature, the high pressure and the low temperature pipeline, also uses in transporting the expensive medium, the flammable explosive medium, the poisonous gas pipeline.
Disadvantages: with neck butt welding flange bulky, heavy weight, expensive, installation positioning is difficult, so in transit more easily bump.
3.Blind Plate Flange
Blind flange is also called flange cover, is the middle without holes in the flange, for sealing the pipe plug.The function is the same as the welded head and the wire buckle cap, except that the blind flange and the screw cap can be unloaded at any time, and the welded head is not.

4. Threaded Flange
Flanges with threaded flanges with pipe ends are of high pressure and low pressure.

Carbon steel pipe flange specifications of threaded flange
Advantages: It is a peaceful welding flange or butt welding flange, threaded flange with installation, maintenance convenient features, can be used in some sites do not allow welded pipelines.Alloy steel Flange has enough strength, but not easy to weld, or welding performance is not good, can also choose threaded flange.
Disadvantage: It is recommended not to use threaded flanges to avoid leakage when the pipe temperature changes sharply or the temperature is above 260 ℃ below 45 ℃.
4.Socket Flange
The socket welding flange is a bolted flange connected to the other end of the pipe.

Carbon steel pipe flange specifications of socket flange
Application Range: Boiler pressure vessel, petroleum, chemical, shipbuilding, pharmacy, metallurgy, machinery, food and other industries.Used in pn≤10.0mpa,dn≤40 pipelines.
5.Lap and joint Flange
Lap and joint flange will be the same material with the pipe welding ring, directly welded in the pipe end, the use of solder ring as a sealing surface, its sealing surface has a smooth and tenon groove type.

Carbon steel pipe flange specifications of lap and joint flange
Function: The purpose of using the ring flange is to save the material, the structure is divided into two parts, pipe and pipe, one end of the weld ring.The flange uses low grade material, and the pipe part uses the same material as the pipe, achieves the material saving purpose.