Modern industry cannot do without such a means of transportation as a pipeline. With its help, liquids and gases are delivered over a rather large distance. In order for the pipeline to last for a long time, it is made taking into account the properties of the materials for which they are intended. Therefore, today there is a large number of technological, trunk and other communications for a variety of substances.
This is a relatively inexpensive form of transportation. How it functions, how the process is organized, existing categories of pipelines will help to understand. There are several different signs of classification. This allows you to use and operate communications as efficiently as possible.
Purpose of the pipeline
The correct definition of the category of the pipeline is necessary both in the production process and in the field. Depending on the type and conditions of transportation, there is a greater or lesser risk when performing maintenance. Bulk, liquid or gaseous products may be transmitted along the line.
The range of applications is great. Pipelines can be used to transfer fuel (oil, fuel oil, gas), chemical reagents (oxygen, acetylene, alkali, ammonia). Also, with the help of the presented communications they can transport oil, water. This system is necessary for both housewives and huge industrial enterprises.
Substances can be heated or cold. The transmission pressure may be negligible or very large. Depending on the type of destination of the system, materials are selected for the manufacture and connection of pipes, a certain marking is applied.
Material
The classification of pipelines into categories and groups is carried out according to various criteria. The material for the manufacture of system elements may be steel, non-ferrous metals, synthetic substances. Each of them has its own characteristics.
Metals weld well in the field. Therefore, the maintenance of such a system is simple and high quality. The wall thickness of pipes and joints should be minimal to withstand the load. Therefore, the production of pipes is constantly being improved.
The material put forward increased requirements. Today, steel, artificial materials are used for the manufacture of pipes. The choice depends on the purpose of the system. Steel can be structural, alloyed and carbon. In some cases, non-ferrous metals are used.
The surface of the product may have a special spraying. But over time, artificial materials are increasingly being used. These are polypropylene pipes. They are easy to install, durable.
Signs of classification
There are various categories and groups of pipelines. There are many classification signs. In addition to the difference in materials, pipelines differ in diameter, ability to withstand pressure, exposure to aggressive substances. There is a separation of systems according to temperature load.
Pipelines also differ in location and scale. Systems can pass on the surface or underground, in water. The scale distinguish between technological, trunk, utility and engine (ship) pipelines.
When creating and maintaining take into account the environmental conditions of communication. Each category or group requires an understanding of its features. This allows you to correctly evaluate the organization of the presented communications, as well as the conditions of their operation.
Classification of trunk pipelines
The main pipelines are designed to transport various types of fuel over fairly long distances. For their manufacture, exclusively metal welded is used. There is either a straight or spiral seam on the pipes.
On the basis of susceptibility to pressure, 2 categories of trunk pipelines are distinguished . Exceeding the specified level is strictly prohibited. The I category of pipes withstands pressure of 2.5-10 MPa, and the II category - 1.2-2.5 MPa.
There are 4 categories of highways depending on the diameter. I of them include pipes with a cross-sectional size of 1-1.2 m. These are the largest products. Category II corresponds to pipes with a diameter of 0.5-1 m. The thinnest varieties follow. Products of 0.3-0.5 m are classified in category III, and less than 0.3 m in category IV. These are the main signs of the classification of trunk pipes.
Technological pipelines
Technological types of communications are used in the production environment. This transport system transfers raw materials and fuel for processing, as well as waste waste.
In almost any sector of the national economy, such systems cannot be dispensed with. Categories of process pipelines classify, in addition to diameter and pressure, according to a number of signs.
The location distinguishes between internal and inter-workshop varieties. Also a very important factor is resistance to heat, an aggressive environment. In the process of performing various technological cycles, communications are subjected to various loads.
Process pipe classification
Technological pipelines are grouped according to a number of important features. According to the method of placement, there are terrestrial, underground and aboveground species. But more carefully in the manufacture and selection of system elements relate to the strength characteristics.
Categories and groups of process pipelines are distinguished according to the pressure inside the system, as well as the temperature of the transported substance. In the first case, the systems are pressureless, vacuum, as well as low, medium or high pressure.
According to the principle of working temperature, there are creagen, cold, normal or hot pipelines. There are also products designed for very strong heating of the transported substance.
Features of process pipes
The existing classification of pipelines into categories takes into account the features of this kind of system. Industrial transportation communications are grouped according to the aggressiveness of the internal environment.
There are pipes for non-aggressive, weak, medium and highly aggressive substances. In production, most often various non-metallic materials are used to create a system. The most famous of them is polypropylene.
A characteristic feature of this group of materials is a long service life, as well as ease of assembly and maintenance. However, the effectiveness of the use of such materials depends on the choice of products in accordance with the operating conditions. For each process today special categories of pipelines have been developed.
Household piping
Considering the existing categories of pipelines, attention should be paid to household systems. Their main purpose is the transportation of liquids or gases through heating systems, life support. They also supply cold, hot water, steam, gas, chemicals for servicing boiler equipment, etc. Alkali, acids, oil, and petroleum products can be transferred through such pipelines.
Indicators of pressure, temperature, aggressiveness of the environment must be taken into account in the production of each category of products. Moreover, take into account the maximum possible values of these indicators.
Piping marking
In order not to raise the question of how to determine the category of the pipeline during operation, special marking is used. This allows maintenance personnel to evaluate the correctness of a particular impact on communications.
Detailed information about the system can be provided only by the accompanying documentation of the manufacturer, the commissioning of equipment. But the basic rules for marking pipelines are successfully applied at all facilities. This allows you to broadly determine which category the pipeline belongs to.
The gas lines are painted yellow. Red markings are reserved for pipes through which steam is transmitted. If the system contains liquid supplying equipment, the system is painted green. For technical water , its own marking is also used. It is a black color. Even visually, you can determine which substance is transported by the system.
Hazard rating
When considering categories of pipelines, it is necessary to pay attention to their degree of danger. It depends on temperature, pressure and the characteristics of the transported substance. Also taken into account remoteness from settlements and the type of location of the system.
According to these data, there are 5 categories of danger: B, I, II, III, IV (presented in descending order of level of threat). This indicator is taken into account during the operation and repair of the system.
Attendants take a number of actions provided for by instructions for repairing communications. Otherwise, an accident or even a large-scale disaster may occur.
Connections
The pipe joints are subjected to a large load from both the external and internal environment. Therefore, they are considered the weak point of any system. Studying the categories of pipelines, it is necessary to evaluate the places of their connections.
Depending on the type, scale of communications, various types of joints are performed. For trunk varieties, they are performed by welding, and for technological varieties it is permissible to weld parts.
For household pipelines, gaskets are required (depending on the type of material and technical characteristics). They are also selected according to operating conditions. In order for the joints to be of high quality, the ends of the pipes must be smooth, the diameter is maintained during manufacture with great accuracy.
In the manufacture of pipeline parts, it is important to produce products of sufficient strength with minimal material consumption. The number of connections is reduced as much as possible. This allows you to create a strong, durable system.
By choosing the categories of pipelines correctly, you can create efficient and practical transport communications. Possessing information about the group, the characteristics of the highways, it will be possible to qualitatively and safely carry out repair of system elements. Therefore, installation and maintenance organizations must consider the categories of each pipeline in their area of competence.