All pipelines are built taking into account the consumption of natural gas by all existing customers. But during the operation amount of the gas used often grows and once the available capacity to transport it becomes scarce.
As a result of highway owners we have to find a way out, and one of the options may be looping pipeline. To which today are increasingly turning professionals and other stakeholders.
Let us see what is the process and how to implement it in practice.
The content of the article:
- What is looping?
Subtleties arrangement and application
- When this method is used?
- Principle of operation loop
- When you can use looping?
- Some editing features
- The norms of the pipeline arrangement
Performing calculations pipeline
- EXAMPLE calculation pipeline line
- Another example of looping
- Conclusions and useful videos on the topic
What is looping?
Name looping process comes from the English word "looping", which translates as "loop". And this is the exact process name with the same name. Since it is the laying of a new pipeline section, the parallel main line.
This branch is always part of the present system and its beginning - Inset into the main branch. And where the design is no need to divide the gas flow, the loop is closed.
Low pressure gas pipeline with looping offloads the main line, to transport the fuel with minimal losses, which is always advantageous
Looping gas serves to solve two major problems, among which an increase in available bandwidth of the main line or decrease the pressure loss during gas transportation.
In particular this applies to roads with high pressure, since it is they are the most unstable conditions, resulting in lower efficiency. And consequently, financial losses.
However, stabilization of the pressure is possible, and in all other types of networks, i.e. the conveying gas at medium or low pressure. Since parallel pipes helps to reduce the pressure at the beginning and significantly improve it in the end.
With looping specialists are able to solve a number of tasks, including the following:
- Using an additional line during the repair of the main.
- Application of such a main artery for changing the configuration. For example, at the time of the gas will pass through the parallel branch to the primary can be adjust the position of lifting stations, which in the future will contribute to a more effective operation of the system.
An important advantage of this construction is the possibility to use it as a main line for gas transportation. This helps in the shortest possible time to get the desired result, and saving money on the arrangement of a new gas pipeline.
Parallel line of the pipeline can be connected to the existing artery anywhere and all you need to do - it's sidebar of the pipe itself, the installation of the two shut-off valves and fittings
Such a method has been known for a long time, but the use of peak at this time. This happens because the gas system in the post-Soviet territory was formed a long time (1975-1990 gg.), And now there is its refinement, improvement to modern needs.
From the above we can conclude that today looping heavily used for several reasons, which include:
- staging construction - initially all the pipelines are built based on needs, and then as needed is an increase in capacity;
- the lack of own funds or investments for the construction of new networks - it happens because of lower demand for natural gas and, consequently, reduce the interest in the sector creditors, investors and even ordinary consumers.
This information indicates that looping may be a cheaper option than the building of a new pipeline full.
Subtleties arrangement and application
Design the parallel pipeline substantially identical main line. In view of this looping it is allowed to use under the same conditions as the main gas pipeline, which is almost all.
When this method is used?
But you should know that the current version to improve performance is only one of several competing methods.
Among them are such as insertion tubes of larger diameter, an increase in power stations with pumping equipment.
The photo shows the place of the union of two gas pipeline lines looping. This can be done anywhere, if unloading the main line was lost need
Additionally, looping may be part of combined methods of unloading the main line. For example, such an embodiment is the use of parallel lines together with the power increase of pumping stations.
Guidance documents allow the use of multiple looping in one area. The diameter of the pipe may be different, but, if the maximum size is not enough for the transport of gas, in different branches are commonly used products of the same size, which provides the same speed of movement fuel.
What can be achieved using a variety of pipe, which leads to the fact that certain sections of the pipeline will wear faster. Although this information is mostly relevant for main gas pipelinesWhere the pressure is always the highest possible.
Assembling the parallel lines can be performed at any time when it is needed and the expediency of such a method the main discharge line
The exact diameter is established only using special calculations, On which the design running on the basis of the guidelines.
Principle of operation loop
After the start of use of the parallel line of the pipeline there is a reduction of fuel volume transported by main line. This reduces the flow resistance that must be overcome, which leads to a substantial reduction of pressure losses.
Therefore, when the same gas pressure possible to transport large volumes of natural gas.
This additional pipe is effective in any of its length. But what she duration, the more pronounced will be the result.
When you can use looping?
As mentioned above, the looping is one of the competing options for unloading any pipeline. Therefore, the technical feasibility and the comparison is required to install it with other methods.
That is, a parallel line can begin to build after its effectiveness is proven in comparison with insertion tube larger, increasing the power of pumping stations, or some combined option.
You also need to know that looping is mainly used for the unloading of gas pipelines transporting where a natural gas to large consumers, which is a city, large enterprises, Other.
Looping of the pipeline is used, if one pipe is the maximum size will not be able to transport the required amount of gas
For households and other small consumers maloaktualny this method, since in most cases the gas supplied in sufficient quantities is not due to congestion pipes, and in case of incorrectly executed hydraulic calculation.
Even if the system is operating at the limit due to the fact that the number of consumers (gas stoves, water heaters) in the home has grown, it usually one optimal exit position will be setting the larger diameter pipe for the main line and not the use of looping.
Reasons irrelevance of such a method for low-power pipeline that:
- Any pipeline from the looping will solve the problem, which can handle any of the parts of the structures individually.
- Each parallel pipe line can be put into operation after the approval of the same project, as in all other cases. That is to create it will take as much time as that for conventional, similar costs will be and that also does not provide a competitive advantage.
- For the construction of looping uses the same materials as for the main line, which again does not facilitate the task.
- The aesthetic appearance of the gas pipeline with looping may be worse than usual because several lines, the more massive the support is unlikely to decorate a personal plot.
In view of all the foregoing, the representatives gorgaza can easily reject the draft gas pipeline looping, as unfounded. This may happen because it will be difficult to explain why for small consumers need sophisticated line of sight.
On the pipeline with looping subject to the same requirements as to normal, so the project preparation procedures, installing similar
Therefore, even if there was such idea, in the early stages of creating the desired project should contact the responsible persons of the gorgaza to perform matching.
Some editing features
Since each parallel line is a conventional gas pipeline, it is subject to all rules and regulations for such structures. As a result, after the creation and approval of the project is usually inset the new pipe to the main pipe.
The only important feature is the need to overlap the existing pipeline on both sides. What can crash Special shut-off valves for pressure relief fittings and other equipment.
The norms of the pipeline arrangement
On looping apply the usual rules for all pipelines. Therefore, work can start only after the approval of the relevant project. They have the right to produce professionals who are authorized.
All equipment and materials to be used for the construction must be tested for the presence of corresponding certificates, damage and other defects.
When the arrangement is used the steel pipe, more precisely, their individual species undergone special corrosion treatment, and their plastic counterparts.
For looping should use only certified pipes and other components, as well as to control the fit of the pipe to the ground, a number of other parameters
Necessary work is done in stages, that is, this operation begins with the preparation of looping the assembly. What digging trenches mounted supports, installation occurs more shut-off valves on both sides, are settling receivers to which the next stage is welded tube parallel line.
During the construction of the responsible persons are required to monitor a number of important parameters, which include adherence to the bottom the trench, the distance between the various communications - both sides and belonging to the structure of the pipeline. Special control exposed welds and corrosion-resistant coating.
After the end of the installation of the parallel line should be performed appropriate tests. Before carrying out such operations need to make preparations.
For example, a trench in which looping is mounted must be sprinkled with a layer of soil. But completely fill it unnecessarily, as this procedure is performed only after successful completion of testing for suitability for use.
Performing calculations pipeline
Guidance documents allow you to perform calculations looping only by means of special formulas. Some of them will be attached below, but beforehand it can be said that only experts can perform calculus.
Since when it is run using a number of different variables, which makes the task difficult.
Calculation of gas pipeline looping - the procedure is complicated, so only qualified personnel may perform it. But even they needed to carry out the coordination of the project with the early stages of Gorgaz
That is the person or organization is interested in project development and construction of looping, will not be able to save even on preliminary calculations.
Because unlike some other similar procedures, for example, hydraulic design, easy and affordable way to a computer is not in use. As a result, the designer must have a sufficient supply of specialized knowledge.
Continued calculation of gas pipeline looping. A large number of formulas, values of variables that must be considered, further complicate the task
After calculation, it is recommended to contact the Gorgaz to perform matching. If it does not perform and develop a project completely, it can lead to significant financial losses. Because they can not be observed in any of the numerous requirements gasman.
Also we recommend that you read our article on the design of the gas supply system. Read more - go on link.
EXAMPLE calculation pipeline line
To calculate the parallel line of the gas pipeline is necessary to know the number of initial data, including volume, time of gas flow, gas resistance coefficient of fuel temperature and a number of other data. All the information you need to take a pre-compiled schema.
Calculation Example particular pipeline with Lupine where design took into account the different types of gas flow, its temperature coefficient of resistance and other parameters
Example of calculation complexity of further evidence that this work should be handled by experts or errors could not be avoided. Resulting in a loss of time, money.
For more information on how to settle the gas pipeline system, see the this material.
Another example of looping
One of the most famous gas pipelines with looping, put into operation in recent years, is a parallel line highway "Pelyatka-North Soleninskoye". Its length is 30 km, but the construction had to arrange a lot of 160 km of road.
In addition, it was required to build almost 90 km of cable. Work was carried out more than five hundred qualified for six months.
Arrangement consisted of the following stages:
- installation of piles, which was preceded by drilling;
- followed by welding installation of support structures;
- stacking the pipes themselves with welding looping;
- quality control of welded joints;
- cleaning looping;
- then running the test in a test mode;
- anti-corrosion treatment of all metal elements.
The stages are listed in the correct order. As a result, said looping allows cost-effective to transport natural gas to users, and smoothly.
As pointed out by experts, the economic effect of the use of the 30-kilometer pipe will make an impressive 6.5 billion rubles, and this is only for 2 years from the date the line into operation.
Conclusions and useful videos on the topic
This short video to better understand what the pipeline with looping:
Any looping able to unload the main line, this increased amount of fuel conveyed to consumers. At the same time, without any increase in costs. At the same time a parallel line of the gas pipeline is not a panacea for all sorts of occasions.
Therefore, prior to the development of the project is necessary to ensure the feasibility of using this option, the network of discharge.
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