Natural gas provides a person with warmth and hot food. However, to implement these functions, it must be brought to the dwelling - to equip the pipeline connected to the central network, heating equipment and household appliances.
At the design stage of the pipeline, it is necessary to figure out which permits are to be drawn up, how to properly crash into a gas pipeline, and whom to entrust such responsible work. Answers to these questions are detailed in the article.
In addition, we described different ways of connecting to the central highway, and also outlined the features of connecting to a plastic and metal pipeline.
The content of the article:
- What are the gas transmission lines
- Bandwidth calculation rules
How to connect to the pipeline?
- Prepare for the tie-in
- Features of the tie-in process
- Rules of performance
- Possible ways to join
- Features insert into the metal gas pipeline
- Insert in the plastic pipeline
- Conclusions and useful video on the topic
What are the gas transmission lines
A gas pipeline is a specialized pipeline, the purpose of which is to transport and store certain amounts of blue fuel. It may have different structural features, which differ depending on the tasks assigned to the mainline.
For example, networks of international importance deliver huge amounts of gas over long distances, because they maintain a constant pressure at a high level. That is why any experiments with gas supply systems are inappropriate and can be dangerous not only for you, but also for others.
So, the best option for working with the system will be to call the relevant services specializing in working with gas communications, which meets the requirements of the legislation.
The gas pipeline must be installed by a gas service specialist who has the required level of tolerance and complies with all safety measures.
Pipelines are arranged like the circulatory system of the human body. Their role can be compared with coronary vessels. And already from the central pipes of regional significance, distribute the blue fuel between consumers.
They are less main, therefore pressure in them is much lower. However, even in such gas networks, its jumps are possible both downwards and in an increasing direction.
Connection to gas communications occurs when the organization has special admission. A wiring inside your home, you can try to implement his own. To do this, it is enough to know a clear sequence of actions and adhere to the necessary security measures.
Bandwidth calculation rules
The main factor responsible for the continuous supply of blue fuel to consumers is the value of the pipeline capacity. The calculation of this parameter is carried out according to a special algorithm. Moreover, it is made regardless of the type of pipes used.
Maximum throughput gas pipe can be calculated by the following formula:
Q max. = 196.386 × D² × P / Z × T,
- R - working pressure maintained in the pipeline, plus 0.1 MPa or absolute gas pressure;
- D - internal diameter of the pipe;
- T - temperature of pumped blue fuel, measured on the Kelvin scale;
- Z - compressibility factor.
This formula establishes the following pattern: the higher the value of the indicator T, the greater should be the network bandwidth.
Otherwise, there will be a depressurization of the gas transmission line, which will inevitably lead to an explosion of this dangerous substance.
Having made the choice of the type of pipe for the gas pipeline, it is important to correctly determine the method of tapping
There is a more complicated formula. However, the algorithm given above is quite sufficient for making the necessary calculations preceding the tie-in to the gas pipeline.
How to connect to the pipeline?
Insertion into the backbone network cannot be carried out personally - only with the help of specialists from gas companies that have permits and permission to carry out such work. Regardless of the chosen company, before connecting to communications, there is a large-scale preparation stage.
Prepare for the tie-in
If you decide to entrust the process of joining the gas network to the specialists of the relevant company, then you need to contact the licensing service. Here, in addition to filing an application of the established sample, you will need to provide a package of documents provided for at the legislative level.
On the eve of the tie-in to the gas transmission pipeline, it is necessary not only to make correct calculations, but also to obtain permission from gas producers
When it comes to inserting a newly constructed building into the gas pipeline, the owner should first of all provide a passport, an identification code and an approved gas supply system design.
In addition, a set of documents should be prepared:
- statementpersonally certified by the head of the territorial division of the gas industry;
- connection permission to the gas pipeline, issued by the planning department of architectural arrangement;
- photographmade in the process of topographic survey of the area where the inset will be implemented;
- technical passport to a private house, or his copy, certified by a notary.
The picture must be certified by authorized employees of the gas service. It will capture the entire engineering infrastructure, including not only gas communications, but also water supply, heating pipes and sewers.
If the house is under construction, then an appropriate architectural design, permission to build it and a floor plan should be provided.
And if its total area exceeds 300 sq. M., It is necessary to submit a thermal calculation of the structure, situational 1: 5000 scale plot plan, neighbors consent to join the gas network, written form.
The last document will be needed in the case when it is planned to put a part of the pipeline underground under the sections belonging to them.
On the eve of the work on laying the pipe for tapping into the pipeline, you must obtain a documented permission of the established sample.
In most cases, permits of this kind are issued by the city government. gas facilities, since they are the full owners of gas transmission highways.
In addition, you will need to provide technical passports or other documents attached to gas appliances that are planned install in the building - permission to use the equipment in the place of residence, certificates of conformity, as well as contracts for service.
You will also need an inspection certificate for smoke-ventilation ducts and other documents stipulated by the legislation. Only with all the permits and acts in hand, you can begin to work on the sidebar, i.e. only legally.
It must be remembered that unauthorized connection to the gas pipeline, without registration in the prescribed the law, the order of proper documents and coordination with the relevant services, is fraught with administrative measures. And if at the same time there was damage to the pipeline, then a criminal penalty.
Features of the tie-in process
The process of tapping into a gas pipeline is the connection of a new pipe through which the substance from the central highway will be transported to the consumer. As a rule, such connections are made without shutting off the gas supply in the trunk network.
The use of such a product for connection to gas pipelines through the valve allows you to perform the full range of works on the tie-in without reducing the gas pressure. Explanations to the scheme: 1 - cup milling cutter, 2 - spindle, 3 - ratchet mechanism, 4 - bar, 5 - chamber, 6 - chamber gland, 7 - pressure screw, 8.9 - handles, 10 - coupling, 11 - socket, 12 - gate valve, 13 - stop bolt (+)
There are certain points to consider. One of them is the high pressure in the main pipeline, so the work on the inset is carried out using a special device. And this is done after the completion of the installation and testing the operability of the installed pipeline for the new consumer.
If the construction of an individual branch can be carried out by employees of private companies, and some of the processes are done by the owner himself, if appropriate skills and tools, only a specially trained staff member can follow the connection to developed instructions.
His actions will be led by a gas service specialist.
Rules of performance
The set of rules that must be observed when performing a tie-in to the gas pipeline is not difficult to memorize. However, in the process of connecting it should be strictly adhered to.
These are the following points:
- When the network is characterized by low pressure, it is recommended to insert a tie-in in its communication with indicators from 20 to 80 mm of water. Art.
- Work with the pipeline under medium or high pressure is allowed only after its level is reduced to acceptable values.
- If the reduction of pressure is technically impossible to perform, it is necessary to resort to assistance of specialized equipment that is intended for work in non-standard conditions.
- It is important to attract employees of relevant organizations that have special permission to carry out this type of work.
- If welding and gas cutting are to be used, the pressure at the site should be monitored, which during installation should be maintained in the range of 40-150 kg / cm.
Compliance with the complex of these simple rules will allow you to avoid abnormal situations in the process of tapping into the pipeline and to ensure the safety of others.
Insertion into the gas pipeline is carried out while observing the pressure control in the gas pipeline
Possible ways to join
The connection of the new blue fuel supply network to the existing one is carried out with the help of tie-in or welding.
In the first case, the work of the main pipeline is not subjected to drastic changes, since the process of cold tapping into the gas pipe is carried out without using welding. The volume of the pumped substance and its pressure do not change and are still kept in the operating range of the network.
This method is used to connect new consumers. To perform work associated with the central network, you must have permission and permission to conduct gas hazardous actions.
Without special training, it is absolutely impossible to interfere in the operation of the main pipeline. Violation can lead to tragic consequences with death or imprisonment.
In some cases, the tie-in to the pipeline should be performed with the intersection of the axes of the networks. Explanations to the scheme: 1 - connecting pipe, 2 - working gas pipeline, 3 - “window” (cutting wall), 4 - visor, 5 - wooden disc, 6 - welded shock, 7 connecting nipple, 8 - rod for extraction, 9 - pad (+)
The second option is more common for joining the majority of the inhabitants. He is reliable and managed to pass the test of time. However, a specialist conducting a sidebar in this way must necessarily have a high level of professional qualification, as well as have a special permit.
The methods of joining themselves are:
- insert into the pipeline under low pressure;
- under medium and high pressure gas, when special devices are used;
- with gas disconnection and complete pipe discharge from it.
The choice of the method of connection to the gas pipeline depends on a number of factors. Therefore, the decision must be made by the connecting people in each individual case.
As for the performer, there may be 2 options: representatives of the gas service or employees of a private company, having the legal right to perform actions, as well as the necessary equipment and access to gas hazardous works
Moreover, in the second case, the office may undertake obligations on the preparation and execution of a package of documents for a legal tie-in to the main gas network. True, all additional services will affect the final cost of connection.
Not only the perfect operation of the pipeline, but also the safety of the entire gas transmission system, depends on the correct choice of pipes.
Features insert into the metal gas pipeline
Insert into the central branch of the metal pipes is carried out after drawing up a sketch of future work and the preparation of all materials that will be useful in the process based on the chosen method of connection.
The first is doing the cleaning of the working surface. At the same time, they remove absolutely everything unnecessary from the place selected for connection to the gas pipeline: garbage, paint, rust. Next, carry out the layout of the tie-in place, putting down the mark. Make the necessary holes.
After this well treated well. During the dissection of the surface of the pipe slit carefully coated with clay. This is required to minimize the risk that the oozing gas will ignite when the incision is made.
The holes are closed as soon as possible with an asbestos-clay plug, and the place that has undergone treatment is rapidly cooled.
Pipe connections should be made in such a way as to achieve the most accurate intersection of the axes of pipelines.
The next stage of work will be the installation of the disconnecting device. After the metal has cooled down, the plug is removed in order to be able to remove a section of the cut pipe from the pipeline.
Now, a disconnecting device is installed in the gap formed. It consists of a set of rubber and wooden discs and bags filled with a viscous clay consistency.
Next, install the nozzle. Having closed the hole with a disconnecting device, they begin to make the main hole intended for connecting a new pipe. First of all, it is necessary to verify the correspondence of the diameter, because sometimes the markup has to be corrected.
Next, make a hole and mount the pipe. Its butt joints are welded on both sides by welding and the gate valve on it is closed. After close up holes.
Having completed the installation of the nozzle, proceed to welding a new pipe. Before this, the metal slag formed after the main hole is made is removed. After cleaning the surface of the pipeline, install a new pipe in the holes and, having covered it with clay, make welding seams.
Next, take an aqueous solution of soap and carefully coat them with new seams, making sure they are tight and there is no leakage of blue fuel.
Pipe joints should be carefully checked for blue fuel leakage by lubricating them with a solution of soap and water.
If gas leakage is not observed, proceed to the final stage of work, that is, fall asleep trench. However, this is not such a simple operation as it seems at first glance.
Trenching should also be carried out in accordance with the standards below:
- around the circumference of the ball valve and connecting pipe tie-in area, it is necessary to fill the soft soil with a layer of more than 20 cm thick and compact it;
- The final backfilling of the trench with the soil is strictly forbidden to be done with a bulldozer or other heavy construction equipment.
Hitting the above-mentioned equipment on the soil layer, covering the place of tie-in, and the pipes running from it, as well as on the ball valve, protruding above the ground surface, is strictly prohibited.
Insert in the plastic pipeline
Connection to gas pipelines made of plastic pipes is not so expensive financially in comparison with steel gas transmission lines. And in the case of plastic pipes, this is much easier to do than with metal ones. It is important to follow a clear sequence of actions.
Plastic products for installation of engineering structures are now used quite often.
The advantages include:
- expensive insulation materials are not required;
- reasonable price with a high level of manufacturability of installation and construction works due to the use of automatic welding machines, low demand for heavy equipment and expensive employees;
- service life - at least 50 years;
- minimum costs during operation and repair.
On the eve of the tie-in, it is necessary to purchase quality fittings made at the factory in accordance with the requirements of GOST (connecting elements). And also to give the seams greater reliability, you will need to use a specialized glue and socket connection.
In addition, care must be taken to ensure that the pipe joint is as tight as possible and has the best density. On the eve of the installation, the processing of the insert must be performed with an anti-corrosion agent.
Regardless of which method of tie-in to the HDPE pipe is selected, all actions should be performed using a special technology.
As for the process of tapping into a gas pipeline consisting of plastic pipes, it is carried out as follows. Connect pipes with special steel or polyethylene inserts. They are located perpendicular to the existing gas transmission system. Their length can be from 80 to 100 cm.
The process of building itself is carried out by means of plastic pipes with a socket-contact joint in the base. The technology of tapping into the gas pipeline is carried out as follows: heating the steel insert to a temperature of 60 ° C on it quickly and physically puts on a plastic construction.
A fairly popular technology is the attachment through the use of a ball valve. The maximum diameter of the pipeline from plastic products, which can be inserted, is 500 mm for models with SDR 11 and 800 mm - with SDR 17.6.
In this case pressure in the gas transmission line must not exceed 1 MPa (10 bar). The very technology of tapping into gas pipelines made of polyethylene pipes is carried out in a certain sequence.
It is possible to crash into a polyethylene pipe without using welding; in this case, resort to the use of a special clamp
The first is welded tap. On the eve of the installation of the equipment in the existing network, the fittings and the inset heaters are installed (coupling and surface care), the ball valve is installed in accordance with SP 42-103-2003.
Next is the assembly and installation of equipment. The drill rod, at the end of which the cutter is mounted, and the insert assembly are fixed on the free branch pipe of the ball valve. To do this, he bolted half the device for clamping. These actions allow you to get absolutely tight connection.
The next step will be tie-in node clamping through the union with the crane. At the same time, the pressure should be more by 0.1 MPa, rather than in the existing gas transmission line.
After being inserted into the pipeline. The drill rod rotates by means of a ratchet lever, forwarding the mill, which, in turn, cuts through the wall of the pipeline.
Then the bar with the cutter is fed back, and the ball valve is closed. The moment of entry of the cutter inside the existing gas transmission line is determined by decreasing the force with which the drill rod rotates, as well as by changing the length of its stroke.
After the hole is made, the drill rod with the cutter is retracted, rotating the arms of the device for cutting through counterclockwise. As soon as the cutter will be removed outside the ball valve, it must be closed.
Further actions to insert into the gas pipeline should be aimed at sealing the butt joints and checking their safety.
After that, it is necessary to relieve pressure in the inset assembly into the gas pipeline, and dismantle the equipment. Shutting off the faucet, gas is released from the tie-in assembly through the vapor hose and tap with a choke. At the same time, the equipment is removed from the free branch pipe of the ball valve. Now the cutter from the drill rod can be removed.
At the next stage, it is necessary to remove the cut pipe fragment from the cutter and remove the formed chips.
Then joins the removal of the pipeline. It is welded using a coupling to the free branch pipe of the ball valve. After the blue fuel is started up, the weld must be pressed under the working pressure, pre-treatment of the joints with an aqueous solution of soap in order to ensure that there is no leakage gas.
The contract for the supply of blue fuel must be concluded at the end of the process of tapping into the gas pipeline in order to legalize the connection
Successfully completing the tie-in to the gas pipeline, it is necessary to do the documentary part of the work, concluding an agreement on supply, technical and emergency dispatching services with a regional representative of the gas company in region.
Acceptance of a new gas facility after completion of the tie-in process and sealing devices controlling the amount of blue fuel consumed, are carried out by a representative of the above-mentioned the company.
On our site there is a block of articles devoted to connecting gas to a private house, we advise you to read:
- How much is the connection of gas to a private house: the price of organizing the supply of gas
- How gas is connected to a private house: input device + system installation
- Gas connection specifications: the procedure for obtaining the necessary documentation
Conclusions and useful video on the topic
The video shows a real-time inset under pressure without gas overlapping:
Video about inserting into the existing high pressure gas pipeline:
Example of making a tie-in to a gas pipeline under pressure in a video:
Having a general understanding of the technical requirements and the procedure for work on connecting to the gas network will be easier to navigate in all the nuances, as well as to control the work of the company with which the connection agreement has been concluded, will simpler.
In addition, the absurd desire to crash into a gas pipeline on its own will disappear, inviting a handyman to save money.
Share with your readers your experience in negotiating documents and connecting to the central gas pipeline. Please leave comments on the article and ask your questions. Feedback form is located below.