Connecting element flange- this is a disk or flat ring with holes that are necessary for fastening. It is secured using studs and bolts that hermetically seal the connections of pipeline fittings and pipes.
Flange types:
- flat;
- threaded and collar.
Flanges flat They are connected to the rear surface of the pipeline by welding. Therefore, flat flanges have an internal diameter larger than the outer diameter of the pipe. When choosing a flat flange, not only the value of the nominal pressure is taken into account, but also the influence of the transporting medium and the effect of the operating temperature.
Collar flanges butt welded to the pipe. Thus, the internal diameter of such a connecting element coincides with the diameter of the pipe. Ensuring high tightness and reliability of the joint, collar flange widely used in pipelines. A threaded flange is generally not used in the pipeline.
Differences in mounting method:
- for pipes;
- for shaft;
- for fitting;
- for body parts.
The flange is ideal for all pressures and pipes. At the same time, this connecting element must be permanently tightened in order to avoid a decrease in tightness.
Flanges - connecting elements of pipelines
What is a flange? This part looks like a disk or ring with holes drilled into it. The latter make it possible to install a flange, securing it tightly with bolts. This way, it is easy to connect sections of pipeline, and there is no need to worry that the pipes in this place will leak. By the way, it is worth remembering to constantly monitor the strength of the flange fastenings. Only in this case can you be sure that the leakage of the pipes will not occur, and the flange will perform its intended functions.
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There are two types of connecting flanges - flat and with points.
The connecting flange of the mast is loosened, after which its upper section is manually laid on the edge of the pipe along the chord and secured to the end of the cargo rope. The removed link, secured with a rope passed through the outer bracket, is smoothly lowered over the edge of the pipe, and then lowered to the ground using a cargo winch. In a similar sequence, the lower link of the jib mast is dismantled, then the lower and then the upper platforms are dismantled, using the traffic light platform of the chimney for intermediate storage of their elements.
The dimensions of the connecting flanges are determined depending on the pressure in the pipeline.
The surfaces of the connecting flanges of the housing parts must be flat, without nicks or irregularities. When checking on a slab, the gap should not exceed 0 1 mm.
After fastening the connecting flanges to the flywheel, its position is checked by plumb line and the shaft by the divergence of the cheeks.
The inlet pipe has a connecting flange, with which the valve is connected to a vessel or apparatus in cases where welding is not possible.
The valve is mounted between the connecting flanges of the gas pipeline in close proximity to the well fittings. The valve stem must be in a vertical position and gas flowing through the valve body must be in the direction of the arrow marked on the valve body. The flanges are sealed by metal O-rings installed on both sides of the housing. The impulse tube is connected at one end to the opening of the fitting, and at the other to the gas pipeline after the valve at a distance of 0 8 - 1 0 m from the valve flange. When installing the impulse tube, it is necessary to fill the valve cylinder with solid oil.
The valve is mounted between the connecting flanges of the gas pipeline in a place convenient for operating conditions and technological piping. The seal between the flanges of the gas pipeline and the valve is achieved by metal rings.
| Connecting the inputs to the tank while filling the transformer with oil under vacuum.| Installation diagram of devices for vacuuming the transformer. |
A flange is a special assembly connection in the form of a ring with holes, which is made of various materials, most often steel. The thickness of the part varies in accordance with standards and GOSTs. A connecting flange is used during installation of pipelines and various connecting equipment. Using flanges, almost all components and assemblies that are located along the entire highway are connected.
This element is an auxiliary fitting, because used only between pipes and various systems.
Flat steel flanges
Make flat steel flanges from St3sp. As already mentioned, the design of this part has holes through which the connection is made: a bolt of the appropriate diameter is inserted into them, and a complete nut is inserted on the other side.
Weld-type steel flanges are also available. This shut-off valve has a large scale of diameter differences from 15 mm to 800 mm. These flanges differ in the temperature at which they can perform their task well: at temperature conditions from -70°C to +300°C, as well as at in-pipe pressure up to 25 MPa. The following steel grades are used in the manufacture of these parts:
- Steel 20, Steel 25.
- 09G2S, 10G2.
- 12Х18Н9Т, 15Х5М.
Features of use in different temperature conditions
Naturally, depending on the complexity of the environment of use, the material used to manufacture the shut-off valves differs. For example: from -30°С to +300°С - steel (St3sp, 20, 25); from -70°C to +300°C - 09G2S, 10G2.
Also, steel flanges are made with sealing surfaces in accordance with GOST. Another feature is that at a pressure of no higher than 4 MPa, they are mounted flat flanges. In all other cases, butt-welded flanges with additional sealed surfaces are used.
Find out more about all available shut-off valves, as well as choose the one that suits you best, professional consultants from TK Engineering will help you. We have a large number of parts in our warehouses, according to all sizes and requirements. You can buy a connecting flange by filling out an online application, or by calling the specified number.
Steel flanges - flanges made of steel and various alloys. The material used to manufacture steel flanges can be various grades of steel and alloys. The material for manufacturing steel flanges is selected depending on the technological requirements for the steel flanges included in the flange assembly or flange connection. In the production and manufacture of steel flanges, low-alloy, medium-alloy and high-alloy steel grades are used. The material of steel flanges can be various grades of steel, we list the most common grades of steel used for the manufacture of steel flanges - steel 20, steel 09G2S, steel 15Х5М, steel 08Х18Н10Т, steel 12Х18Н10Т, steel 10Х17Н13М2Т, steel 06ХН28МДТ. All grades of steel used in the manufacture of steel flanges have their own physical, mechanical, chemical, and technological features, which determine the scope of application of steel flanges. The materials for the manufacture of steel flanges are capable of operating in various climatic conditions, from sharply negative temperatures (steel 09G2S), to sharply positive temperatures (steel 15Х5М), in various aggressive environments, under different pressures and operating conditions (steel 08Х18Н10Т, steel 12Х18Н10Т, steel 10Х17Н13М2Т , steel 06ХН28МДТ.The production and production modes of steel flanges are directly related to the materials of production and production. Knowledge of the necessary subtleties and features of materials for the manufacture of steel flanges and flange connections is vital for the production of high-quality and inexpensive products. The main reference document for materials for the manufacture of steel flanges is the steel and alloy grade. This directory contains various grades of steels and alloys, with their various properties, characteristics, features of heat treatment modes and hardness.
The choice of material for the production and manufacture of steel flanges greatly simplifies the grade of steels and alloys; it is possible to select a steel or alloy with the necessary characteristics and requirements for operating conditions. The grader of steels and alloys greatly simplifies the selection of the required material for the manufacture of steel flanges. In the production and manufacture of steel flanges according to the standards of foreign countries (DIN, EN, ANSI, ASME) and others, marking, and as a result, specifications the grades of steel and alloys used differ from our GOSTs, but in basic properties, processing modes, chemical composition they are still quite close, so it is quite possible that when manufacturing and producing steel flanges according to foreign standards, it is possible to select steels regulated by ours or those that are similar in basic properties and chemical composition.
In the current economic conditions, the production and manufacture of steel flanges is acquiring ever wider forms of cooperation; more and more new technological equipment is being supplied to Russia, which requires periodic repairs during operation, and at this stage the need arises for the production of repairable components and assemblies (including including steel flanges). The ability to replace foreign manufacturing materials with domestic materials is a necessary task when repairing and replacing individual components and assemblies of equipment.
Flange connection
Flange- this is a part with which pipes, microwave waveguides and pipeline fittings. Externally it looks like a ring or flat disk with holes for bolts and studs spaced evenly around its circumference. In addition to round flanges, rectangular flanges are also produced - they are used mainly in connecting units for gate valves and valves, where the pressure does not exceed 4 MPa. Flanges are always used in pairs. To put it very roughly and simply, flange connection it is created like this: on one side the flange is connected to the pipe (most often it is welded), and on the other - to the second flange (using bolts, nuts, washers or studs). A sealing gasket must be placed between the two flanges. It ensures tightness.
Main types of flanges:
By design, flanges are divided into:
- Flat welded
- Butt weld
- Loose on the welded ring.
Butt weld flanges are also called collar flanges. In the middle part they have a protrusion in the form of a truncated cone - a “collar”. When connecting parts, it is this protrusion that is welded to the end of the pipe.
What are the differences between different types of flanges?
In Russian industry, the following types of parts are most often used:
- Flat welded steel flange, GOST 12820-80
- Steel welded collar flange, GOST 12821-80
- Steel flange with internal thread, manufactured according to DIN 25662, or according to a new similar standard - DIN EN 1092-1 (type 13B)
The welded collar flange (GOST 12821-80) can be used in connecting units of systems with high pressure- up to 20 MPa, or up to 200 kgf/cm2. Their nominal passage diameter can be no more than 1600 mm. Collar flanges withstand extreme temperatures. The most “resistant” models can be operated in the range from -253°C to +600°C. When creating a connection, the welded collar flange is secured with one weld so that the end of the pipe is necessarily connected to the “collar” of the flange. Flanges with internal threads are used in low-pressure systems for connecting pipes and installing shut-off and measuring valves. The maximum operating pressure is 1.6 technical atmospheres, or 16 kgf/cm2. The temperature of the working environment according to standard 2566 can be from -30°C to +450°C. According to the internal diameter of the part it is carried out metric thread certain parameters, which is selected for the corresponding surface of the pipe or fittings.
When selecting flanges, it is important to know:
- Dimensions of the parts to which the flange connection will be mounted - the dimensions of the flange are selected for them, in particular, the nominal diameter of the passage
- Operating pressure in the system for which the flange connection is intended
- Connecting dimensions - in accordance with connecting row 1 or row 2, a different number of holes are made in the flange for fasteners (bolts, studs), their diameters will also differ
- Design of the sealing surface - for welded collar flanges according to GOST, there are 9 design options for certain surfaces: with a tongue, a groove, a connecting projection at 45° and at a right angle, for an oval gasket, for a lens gasket, etc.
