The main gas pipeline is a complex of special structures. It is intended for transportation of combustible raw materials from a production or production site to end consumers. The main gas pipeline can be high, medium and low pressure. Accordingly, there are complexes of classes 1, 2 and 3. 
Performance
It is determined in accordance with the data on the fuel and energy balance of those regions in which the construction of gas pipelines is supposed, according to the annual rational amount of raw materials. At the same time, the volume of its use in the future is taken into account. Loops can be constructed in various areas to increase productivity. When calculating the stationary mode of operation in the process of solving a number of problems, their location does not matter. A significant increase in productivity is facilitated by centrifugal blowers with drives from turbines or high-power electric motors.
Automatic regulation
To characterize the management of main gas pipelines, it is necessary to establish the stability of the entire system and analyze the unformed processes in the complex that provides long-distance transportation of raw materials. The latter acts as one of the main factors affecting the choice of a specific automatic performance control. The transition process should not occur arbitrarily. As a rule, they have a fading character. In the process of calculation and subsequent study of the dynamics of the processes for managing the productivity of gas pipelines, specialists deal with inertia. It is due to the movement of the flow of combustible raw materials. Along with this, the work of gas pipelines is accompanied by low-inertia processes. They arise under the influence of the masses of the moving parts of the compression apparatus. Due to the complexity of the automated complex device, it is allowed to consider the impact of these factors separately. The entire system is managed by a state company. In the Russian Federation, this is OAO Gazprom. 
Main gas pipelines: designations
Signs act as warning and information tools. They provide visual recognition of the complexes, determine the area through which the main gas pipeline passes, during the implementation of any measures within its security zone. Signs are an integral element of complexes. Their presence indicates that the company complies with the rules of gas pipelines. Signs of fastening the threads of the route on the ground are set to tie the complex to a specific territory, to indicate the area of the security zone, as well as the depth of the elements. They look like columns equipped with two posters. The first provides information on the width of the territory under protection, the location and additional technical characteristics. It is fixed vertically. The second poster is used to visually detect the required areas from the air. It is fixed under a slight slope to the surface of the earth (no more than 30 degrees). It indicates the distance along the entire route (in kilometers).
Design
The main gas pipeline is created in several stages. First of all, pre-project preparation is carried out. This process is based on the selection of basic equipment. The design takes into account the amount of fuel that will be used, the power that the station will have.The main gas pipeline is developed in accordance with the pressure indicators necessary for the operation of burners and other consumption systems. In the presence of calculations for thermal load, it is necessary to clarify the possibility of gasification. For this, a situational map of the territory should be available. All conditions in which the operation of the main gas pipelines will be carried out must comply with the provisions of SNiP. 
Insertion Point
It is determined by engineers who take into account a large number of different factors. If the main gas pipeline is located near the facility where potential consumers are located, this does not mean that the insert will be made to it. The point can be located in the track, which is located in the distance, up to several kilometers. When determining the tie-in section, the technical capabilities of providing potential consumers with the necessary volume of raw materials with a certain pressure are taken into account. In addition, conditions should be provided under which it will be possible to repair the main gas pipeline. Designing is a complex and rather laborious process. It is more advisable to entrust it to competent specialists.
Connection
To insert into the gas pipeline it is necessary:
- Get documentation and specifications for joining an existing system.
- Coordinate the project with the control authorities.
- Install the external and internal gas pipelines.
- To develop and transfer executive technical documents to enterprises serving buildings.
- Get the subscriber’s book.
Transitions
They can be of two types: sub and surface. The first are arranged perpendicular to the axis of the water flow. When arranging the crossings, allowable gaps between the parallel pipelines are provided, depending on their diameter. In this case, the depth should be not less than half a meter from the level of the supposed erosion of the bottom to the surface of the route and not less than 1 m from the design elevations. In the process of construction of crossings over flooded or water areas, pipes are equipped with special weights to prevent ascent. Continuous concreting or backfilling with mineral soil can also be carried out.
The sections of passages through various kinds of obstacles (both natural and artificial) are subject to requirements, the observance of which ensures the reliable operation of pipelines and their safe use in the future. The method of construction is selected in accordance with a comparative analysis of the indicators of several methods. The transition cavities are cleaned by flushing. Elevated elements can be arched, hanging or beam. The choice in this case depends on the conditions in which the construction is carried out.
Elevated passages are used at crossings through ravines, small rivers, etc. A self-supporting pipe is provided in the beam structure. Hanging transitions can be cable-stayed, sagging and flexible. In the latter, fastening is carried out using suspensions to several (or one) cables. They are thrown over the pylons. In cable-stayed systems, the pipe is held in the design position due to inclined cables or rigid trusses. Arched passages are used primarily when crossing canals. They include rigid structures. In sagging transitions, the gas pipeline sag freely under its own weight and mass of fuel. 
Compressor units
Such stations are used to maintain pressure, to ensure the movement of gas in specified volumes. They are built along the route. In compression stations, gas is purified from impurities, drained, compressed and cooled. After that, under the necessary pressure, he returns to the pipe.As a rule, compressor stations are constructed in a complete block design. This means that the equipment is delivered in the form of blocks that are completely ready for installation. Pumping units are mounted in individual or group buildings, as well as in special shelters.
Construction Features
Buildings for stations are equipped with lightweight steel frames. Roofs and walls of such structures are made of lightweight 2- or 3-layer panels. In the latter case, the elements have a special frame-frame. It is closed on both sides by steel galvanized, asbestos-cement or aluminum sheets. In accordance with the pressure performance in the manifolds, the stations can operate according to schemes consisting of one, two or even three successively introduced superchargers. In the process, it is allowed to use their groups, including two to three units connected in series. 
The state of the industry today
Modern gas pipelines are complex structures in their construction. Their use can be carried out only in the presence of automated systems. Their operation, in turn, should be based on the results of technical analysis of pipelines. The construction of modern routes requires considerable financial and material costs from the enterprise. High costs are due to the significant remoteness of the main deposits from end users. There are a lot of problems in the industry. They are associated, in particular, with the physical and moral obsolescence of equipment. Many sites require reconstruction and updating of technical equipment. All this is fraught with considerable financial costs. 
Conclusion
Gas today is considered in Russia as one of the key fuel materials. He goes to a huge number of consumers, removed at a variety of distances from the fields. Such popularity of this raw material is determined by its relatively low cost. Today, Gazprom is the key company responsible for the supply. It is this company that provides most of the population with this type of fuel. To meet the needs of consumers throughout the country, gas pipelines run to which infrastructure facilities are connected. The key objective of the supplier is to ensure uninterrupted transportation of fuel to users. This requires maintaining the gas pipeline system in good condition. There are many enterprises in the industry that service certain sections of the tracks. The state of highways depends on their activity.
