Natural gas provides a person with heat and hot food. However, in order to implement these functions, it must be brought to the dwelling - to equip a pipeline connected to the central network, heating equipment and household appliances.
At the design stage of the highway, it is necessary to figure out what permits are to be issued, how to properly crash into the gas pipeline and who to entrust such responsible work. The answers to these questions are detailed in the article.
In addition, we described different ways to connect to the central line, and also outlined the features of connecting to a plastic and metal pipeline.
A gas pipeline is a specialized pipeline, the purpose of which is to transport and store certain volumes of natural gas. It may have different design features that differ depending on the tasks assigned to the trunk.
For example, networks of international importance deliver huge volumes of gas to long distances, therefore, constant pressure is maintained in them on 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.
Which means the best option to carry out work with the system, it will be a call to the relevant services specializing in working with gas communications, which meets the requirements of the law.
The tie-in into the gas pipeline must be carried out by a gas service specialist who has required level permit and comply with all security measures
Gas pipelines are arranged like circulatory system human body. Their role can be compared with the coronary vessels. And already pipes of regional significance depart from the central ones, distributing blue fuel between consumers.
They are smaller than the main ones, and therefore the pressure in them is much lower. However, even in such gas networks, its jumps are possible both downward and upward.
Connection to gas communications occurs if the organization has a special permit. And you can try to do the wiring inside your house with your own hands. To do this, it is enough just to know a clear sequence of actions and adhere to necessary measures security.
Bandwidth calculation rules
The main factor responsible for the continuous supply of blue fuel to consumers is the value of the throughput of the gas pipeline. The calculation of this parameter is carried out according to a special algorithm. Moreover, it is made regardless of the type of pipes used.
The maximum throughput can be calculated using the following formula:
Q max. \u003d 196.386 × D² × P / Z × T,
- R- working pressure maintained in the gas pipeline, plus 0.1 MPa or absolute gas pressure;
- D- inner diameter of the pipe;
- T is the temperature of the pumped blue fuel, measured on the Kelvin scale;
- Z is the compressibility factor.
This formula establishes the following pattern: the higher the value of the T indicator, the greater the network bandwidth should be.
Otherwise, depressurization of the gas pipeline will occur, which will inevitably lead to an explosion of this dangerous substance.
Having made the choice of the type of pipes for the gas pipeline, it is important to correctly determine the method of tie-in
There is a more complicated formula. However, the algorithm given above is quite sufficient to perform the necessary calculations prior to tie-in into the gas pipeline.
How to connect to the gas pipeline?
Tapping into the backbone network cannot be done by oneself - only with the help of specialists gas companies licensed and licensed to carry out such work. Regardless of the chosen company, before connecting to communications, there is a large-scale preparation stage.
Preparing for the tie-in
If you decide to entrust the process of connecting to the gas network to the specialists of the relevant company, then you must contact the licensing service. Here, in addition to submitting an application of the established form, 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 pipeline, it is necessary not only to correct calculations, but also get permission from the gas workers
When it comes to tie-in to the gas pipeline of a newly erected building, the owner should first of all provide a passport, an identification code and an approved one.
In addition, you should prepare a set of documents:
- statement, personally certified by the head of the territorial branch of the gas economy;
- permission to connect to the gas pipeline, issued by the department of planning of architectural arrangement;
- photograph made in the process of topographic survey of the area where the insertion will be carried out;
- technical passport for a private house, or a 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 square meters, it is necessary to submit a thermal calculation of the building, a situational plan of the site on a scale of 1: 5000, and the consent of the neighbors to connect to the gas network, drawn up in writing.
The last document will be needed in the event that it is planned to start up part of the gas pipeline underground along the sections belonging to them.
On the eve of the work on laying a pipe for tie-in into a gas pipeline, it is necessary to obtain a documented permit of the established form
In most cases, permits of this kind are issued by the city's gas management department, since they are the full owners of gas pipelines.
In addition, you will need to provide technical passports or other documents attached to gas appliances that are planned to be installed in the building - permission to use the equipment in the place of residence, certificates of conformity, as well as service contracts.
You will also need an act of inspection of smoke and ventilation ducts and other documents provided for by law. Only having all the permits and acts in hand, you can start working on the tie-in, that is, exclusively on a legal basis.
It must be remembered that unauthorized connection to the main gas pipeline, without registration in statutory 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 gas 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 pipeline will be transported to the consumer. As a rule, connections of this kind are made without cutting off the gas supply in the main network.
An example of making a tie-in into a gas pipeline under pressure in a video:
Having general idea about technical requirements and the procedure for carrying out work on connecting to the gas network, it will be easier to navigate in all the nuances, and it will become easier to control the work of the company with which the connection agreement has been concluded.
In addition, the absurd desire to crash into the gas pipeline on your own will disappear, inviting a jack of all trades in order to save money.
Share with readers your experience of coordinating documents and connecting to the central gas pipeline. Please leave comments on the article and ask your questions. The feedback form is located below.
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Any engineering structures, including gas supply pipes, have their own service life, after which they must be dismantled and replaced. If you have planned repairs in the house, then it is worth remembering these parameters so that all cosmetic work can be done after servicing the home gas pipe.
In this article, we will talk about how to make a tie-in in gas pipe to replace it, and what subtleties need to be considered in this process.
Specifications
Uninterrupted gas supplies to consumers' homes directly depend on the throughput of gas pipes. In this regard, the calculation of this parameter is made especially carefully. Moreover, this process is mandatory regardless of the material of the products used - polymers or steel.
To determine the maximum throughput of each specific pipe, the following formula is used:
Q max \u003d 196.386 T × (P / Z) × (D y / 2),
where P is the value of the constant working pressure in the gas pipe, increased by 0.1 MPa; D y - size conditional pass pipes; T is an indicator of the temperature of the gas passing through the pipe in degrees Kelvin; Z is the compression ratio.
Based on the formula, we can conclude that the higher the temperature of the gas transported through the pipes, the greater their throughput should be in order to prevent leaks, loss of tightness or even explosions.
Although in their professional activities, craftsmen often use more complex formulas for calculating throughput, the above calculation method is still more than enough for self-selection of pipes of the desired diameter.
However, to make your task easier, you can take ready-made data from a special table that shows the throughput of pipes depending on the gas pressure in the system.
Preparing to replace gas pipes
Thanks to its complex design The gas supply system performs two functions at once - transportation and storage of gas. Depending on the main purpose, different systems may have their own characteristics. In particular, main gas pipelines, the main task of which is to supply energy over long distances, are characterized by high pressure in the system.
Therefore, tapping into a gas pipe under pressure is a great danger to an untrained person. Such actions can pose a danger not only to the employee himself, but also to the life, health and property of others. Therefore, illegal tapping into a gas pipe, without the involvement of specialists with the appropriate level of clearance and professional skills, is strictly prohibited.
If you do not know how to connect to a gas pipe, or there is a high-pressure line near your house, you should contact a special service to replace the communications in the house, and in no case should you do such work yourself.
At the same time, it is unlikely that your pipes will be replaced already at the first arrival of a gas worker. Usually he first measures the length of individual components of the system, conducts visual diagnostics state of the pipes, after which for several days it is construction estimate. In it he brings everything specifications necessary pipe products, describes the cost of materials and work.
Standards for safe tapping into gas pipes
Before crashing into a gas pipe, you need to take care of safety at the facility. There should be no open sources of fire near the gas pipes, so the place of work must be isolated from smokers, and indeed strangers in general.
In addition, at the approach to the tie-in point in the gas pipeline, warning signs should be placed with the inscriptions “Caution, gas!”, “No passage!”, “No smoking!” and others with similar content. Such requirements are obligatory for execution, in order to avoid accidents.
When making a tie-in into a gas pipe, it is also necessary to follow certain standards for working with them.
The most significant rules are:
- when connecting to a gas pipeline with low pressure, it must be ensured that its value does not rise above 80 mm Hg, but also does not fall below 20 mm Hg;
- if work is planned in networks with high or medium pressure, then before starting the tie-in, this indicator must be lowered to an acceptable level;
- gas cutting or welding of pipes can only be carried out on those sections of the pipeline where the pressure fluctuates between 40-150 MPa. Moreover, it is important to ensure that this indicator is within acceptable limits during the entire time of work.
The standard is legally fixed, according to which only enterprises that have received a special permit or even an order can perform tapping into gas pipelines without reducing the pressure level in them.
Please note that those cases where there is no way to reduce pressure are rather exceptions, non-standard situations. Under such circumstances, special equipment is needed to carry out repairs.
Varieties of tapping and preliminary actions
Stage pre-training is a must in any case, whether you are a beginner or an experienced master. If you yourself do not know how to crash into a gas pipe without welding or otherwise, contact an office that specializes in such work.
When contacting a contractor, when applying for a tie-in, you may be asked to present a whole package of documents prescribed by law for such cases.
When carrying out the initial tie-in into the gas main of communications of a newly built house, the following documents will be required:
- permission for a tie-in into a gas main from an architectural and planning institution;
- a topographical image of a specific area, certified by the gas industry. In addition to gas pipes, all communications connected to the building should be marked on it: water supply and sewerage, heating;
- technical passport or its copy, certified by a notary, a number of other documents.
But those owners who understand the intricacies of tie-in work in the main gas pipelines, and are also quite sure that they can cope on their own, should only purchase the necessary materials. However, be careful, as crashing into a gas pipe is illegal, not entirely safe. In the event of a violation of technology, damage to the main line can be provoked, which can threaten not only harm to life and health, but also administrative and criminal liability.
Dock a working gas pipeline with new branch possible in two ways.
cold tie-in
AT this case the main pipe continues to operate normally without changes in the volume and pressure of the transported gas. They prefer to use this method for the initial connection of new subscribers.
Those who prefer to do their own tapping into a pressurized pipe most often prefer this technology, as it is the easiest to perform.
welding method
But the method of connecting gas pipes to the main lines can be reel or tee. With a coil connection, the ends of the pipes and the operating system are joined, and with the tee method, the axes of the pipelines are crossed.
Connecting the system to the gas pipeline
To tie into a common highway, you will need to carry out the following activities:
- Clean the joint of debris, rust or paint.
- Make a markup, mark the place of the tie-in.
- Make holes, of which there will be two - in the case of the tee method, and one - with the coil.
- Close the cracks with clay. Processing must begin at the moment the surface is cut. This will reduce the risk of gas fire. Close the holes made immediately with a plug made of clay and asbestos, after completion of work, cool the surfaces.
- Mount the disconnecting device after the final cooling of the metal. To do this, pull out the plug and remove the part of the cut pipe. After that, insert a disconnecting device into the resulting gap - it looks like viscous clay sacks and several rubber and wooden discs. In the case of using the tee method, there will be two slots.
- Now you need to mount the pipe through which the gas pipe is connected to the main. But first, check the diameters match. If nothing needs to be adjusted, then make a hole and mount the pipe, then weld the joints and close the valve installed on the pipe.
- We close the holes and weld a new pipe. To begin with, get rid of all the remnants of metal formed during the creation of the main gap. After that, connect the pipe to the nozzle, process with clay and weld. The quality of the weld is checked with a soap solution.
It should be noted that welds and their types have strict designations, and I comply with GOSTs. In this regard, it is necessary to carry out work only taking into account all the requirements and norms that correspond to the characteristics of our gas pipeline.
If no leaks were found, then you can proceed to the finishing work - that is, backfilling the trench. Despite the fact that the work may seem very simple, they must also be carried out in compliance with regulatory documents.
As a rule, such documents contain the following information:
- Soft soil no more than 20 cm thick is poured around the mortise unit, pipe and tap, followed by compaction.
- At the very end of backfilling the trench, heavy equipment should not be allowed to run into pipes, mortise units and a ball valve.
Upon completion construction works it will be necessary to sign an agreement with the local gas service to start supplying blue fuel. In addition, the gas service will be obliged to carry out technical and emergency dispatch services. The same organization will deal with the acceptance of the finished gas pipeline system. After the start-up and adjustment work, it is imperative to draw up an act, as well as seal the gas control system.
Replacement of gas pipes in an apartment, like any other pipelines, is required after many years of operation. Therefore, if you plan to make repairs, pay attention to the service life of gas pipes, since a leak may occur in old pipes and, changing them, the repair will have to be redone at least partially.
The cutting of old pipes is performed by a grinder, and the products of such work, for sure, will not go unnoticed on the walls and other interior elements.
Replacement of the gas pipeline in the apartment
As you know, replacing gas pipes with your own hands is prohibited, so only specialists from gas service companies have access to this type of work.
Therefore, if replacement is necessary, you will need to contact the appropriate institution and wait for the arrival of the master.
Most likely, with the first visit of a gas service employee, the pipe will not be replaced for you, since the master will need to inspect the gas system, measure the length of the gas pipes, draw up an estimate for the work, as well as the cost of new pipes for domestic gas pipelines.
Gas pipe replacement work
Arriving at the installation site, the master must remove unauthorized persons from the site, take care of the absence of smokers and sources of open fire.
Before entering the work site, a warning sign “Caution! Gas!”, “Smoking is prohibited!”, “Passage is prohibited!” etc.
Before cutting off the gas pipe and proceeding with the installation of a new one, the gasman must block the gas supply to the gas pipeline to which the new pipe will be welded, and remove (blow out) the remaining gas from it. Blow gas into the room ( ventilation ducts etc.) is strictly prohibited.
After all safety measures have been taken, cutting of the gas pipe can be performed. As already mentioned, it is usually produced using an ordinary grinder. Next, a new one is welded in place of the old pipe.
Checking the integrity of the domestic gas pipeline and the rules for starting gas
It is forbidden to let gas into the pipe until its integrity, the presence of all the required plugs and the serviceability of the connected gas equipment are confirmed by the method of inspection and appropriate tests (soap emulsion).
When starting the gas, the gas pipeline must be purged until all air is expelled from it. The duration of the purge is determined by analyzing the gas samples taken.
The content of oxygen in the gas should not be more than 1%, the combustion of the last sample should proceed smoothly, without popping. When blowing through the gas pipeline, after the gas pipe has been replaced, it is forbidden to release the gas-air mixture into the room, ventilation outlet, stairwell, etc. When starting gas, the room in which installation work is carried out must be provided with constant ventilation.
During and after the release of gas into the newly connected branch of the gas pipeline system, it is necessary to ensure enhanced monitoring of the operation of the gas system.
Insertion into the gas pipeline
Apartment buildings are often equipped with a gas pipeline system even before the tenants move in. But what if a tie-in into the gas pipe of a newly built house is required? Let's describe what the procedure for gasification of a house looks like.
Preparation of necessary documents
The list of documents required to connect gas to the house is as follows:
- those. home passport or certified copy;
- a snapshot of a topographic survey of the site at a scale of 1:500, certified by the gas service, with a gas pipeline and other communications marked on it ( , );
- permission to connect an architectural and planning institution to the gas pipeline;
- documents for equipment planned for installation in a house to which gas will be connected - a certificate of conformity, a contract for equipment maintenance, a conclusion that it is to be used in housing construction;
- examination certificate (VDPO), obtained after contacting Gorgaz.
How to get permission to tie into a gas pipeline
In Gorgaz, you will need to find out which design organization for gasification of the house they recommend, as this will be the key to the absence of problems in the future. It will be necessary to agree with the design engineer on the placement project and the brand of gas equipment and heating appliances, after which the specialist will independently be obliged to agree on the project in the technical department of Gorgaz.
Read the contract carefully. You should be interested in items with clearly defined guarantees from the contractor.
Installation of a domestic gas system and connection to a gas pipeline
After installation of the piping from the gas pipeline and equipment, the design organization draws up a package of executive and technical documentation. The work is accepted by a special commission consisting of a representative of Gorgaz, the contractor and the customer.
You will also need to pay a technical supervision receipt and provide a copy of it to the installation company. In the near future, representatives of Gorgaz will seal the meter, and a contract will be concluded with the customer for gas supplies and maintenance of his part of the gas system.
Don't know how to crash into a gas pipe? To do this, you will need to hire a special service that performs tie-ins.
Having connected you to the main gas pipeline, specialists will open the gas valve and make a test run of gas, thereby checking the entire system for leaks.
After making sure that everything is in order, you will only have to carry out commissioning of the equipment, which, however, can also be carried out by the seller organization, of course, if you have an appropriate contract for maintenance and warranty service.
It is impossible to join a gas pipeline and a gas-consuming facility that are newly built and operating, as well as those that have not been accepted by a special commission, and it is also prohibited. In order to connect such facilities, an act of acceptance into operation is required, in accordance with the instructions approved by the head of the engineering department of the gas enterprise.
You can join the gas pipeline system, which is in operation, only when gas is released into gas channels or objects. And at the end of the gas wire that is connected, it is necessary to install a barrier cover. If there is a special shut-off device at the end of the gas pipeline system, then a barrier cover must be installed after it. Channels for supplying gas to the premises are still preparatory stage, prior to the connection process, must be disconnected from the internal gas pipeline.
For the commissioning of the gas pipeline industrial production or enterprises of agricultural or municipal purposes, it is necessary to report the connection of the gas system of enterprises to the city distribution source of the gas service of the city in order to launch the gas substance in the network of enterprises. Also inform the district branch of the city gas service by submitting an appropriate application from the enterprise.
Then, when the enterprise will receive gas from the gas main, its gas pipeline must be connected to the gas main on the basis of an act on the acceptance of the gas system. Work on cutting into the gas main is carried out by a special gas service.
All gas pipeline structures and gas facilities, before connecting them, are subjected to external inspection and control pressure tested. Pressure testing is carried out with air or inert gas. The process of pressure testing of external gas pipelines of any pressure must be carried out at a pressure of 0.02 MPa. The pressure indicator may drop, but not more than 10 daPa per hour.
The control process of pressure testing of internal gas pipelines of industrial or agricultural enterprises, an enterprise that serves the population and has production tasks, instruments and devices of the gas pipeline system must be performed at a pressure of 0.01 MPa. But the pressure indicator can only fall by no more than 60 daPa per hour.
Under a pressure of 500 daPa per hour, the internal gas pipeline system and equipment of the enterprise, which serves the population and has non-production tasks, residential buildings and public buildings. The pressure indicator when falling is not more than 20 daPa for five minutes.
tank with liquefied gas, the gas pipeline system of a group cylinder installation is being tested by a control process at a pressure of 0.3 MPa in an hourly period of time.
As a result, the tests carried out can be considered positively completed, provided there are no moments when the pressure drops and there are no leaks. This is determined using a pressure gauge and a soap emulsion.
The results obtained are drawn up in an act and recorded in the order for the implementation of dangerous gas works. The air pressure indicators in the gas pipeline system that is connected must be maintained until the very initial stage connection process and gas launch.
In the case when the gas pipelines that have been inspected and those that have been tested with control pressure indicators have not been filled with gas, then in the conditions of the restoration of gas launch work, they must be inspected and pressure tested again.
Gas cutting and welding work on gas pipeline structures that operate in normal mode, if other gas systems are connected to them, must be carried out under gas pressure within 40150 daPa. These indicators are checked throughout the entire time period while the work is being done. In the event that the pressure begins to fall below 40 or rise above 150, plunging and welding should be stopped. Monitor pressure readings required area using the installed manometer.
The moment of decrease in pressure indicators in the gas pipeline system under the conditions of plunging occurs by a special shut-off device or a regulator of indicators. If special devices are used that ensure complete safety and performance of processes at a qualitative level, it is allowed to connect without lowering the pressure indicators. The method by which the gas pipeline will be connected to the one that is already in operation is established by the enterprise.
The procedure for inserting gas wires with the help of gas is carried out in accordance with the instructions developed by the gas facilities enterprises. Finding persons outside the process, smoking and open fire plunging is prohibited in the work area.
Various pits on the ground in the process of plunging work should be protected near the work area by posting warning signs: No Passing!, No Smoking! and Attention! Gas! Be careful!.
It is also prohibited to start gas in gas system unless it has been checked for integrity through inspection and test procedures, in addition to the correctness of the gas appliances and the presence of the mandatory barrier caps. The launch of gas into special equipment for residential premises is carried out before the residents of the house were settled in it.
When gas is started, gas pipeline structures must be purged until all air is forced out. The completion of the purge can be determined by analysis or by incineration of the samples that are taken. In this case, oxygen should not be contained in the gas in more than 1%, and the test specimen of the gas should burn without exhausts and fairly measuredly.
When the gas pipeline is blown, it is forbidden to spray a mixture of gas and air in the building, on stairwells, in chimneys and in the ventilation system. The building where the appliances that consume gas, gas pipeline, gas equipment when starting the gas substance must be regularly ventilated.
A mixture of gas and air should be released in the event of a gas pipeline being blown in a section that excludes the risks of its passage into the room, in addition, where the formation of a flame from any fire source is excluded.
At the first start-up of a gas resource, it is necessary to carefully monitor that it is supplied with pressure indicators that do not exceed those for which the gas pipeline system was calculated. At the time of launch and immediately after that, it is necessary to vigilantly monitor the gas supply system as a whole, in the case of laying underground, behind all objects, including a basement, a well, buildings that are located on an area with a radius of 15 meters from the gas pipeline gas source. Enhanced tracking is necessary in winter and spring period when the frozen ground mass above the gas pipeline structure can make it difficult for the gas to escape from underground. Do not forget that when gas leaks from a gas channel underground, it moves in the soil mass at a speed of up to 7 meters per hour.
The workflows on the subject of connecting a new gas pipeline to an already fully operational one should be carried out by specially trained people under the supervision of specialists in the gas industry.
Works on connection to the gas network are considered gas hazardous, which are carried out according to a scheme that has been approved in advance. For such work, assignments are made. At the preparatory stage of the workflow, a drawing of the connecting units is necessarily drawn up, a method for connecting work is determined, the procedure for lowering the pressure indicators in the gas pipeline is calculated, of course, where it is required, and they are provided in a stable state for the entire period of connection. Also calculated the right materials, protective equipment, life-saving devices, means of the first medical care. In addition, barrier covers and valves on the gas pipeline that is connected must be closed.
Connection methods
So, there are several ways to connect a new gas pipeline to an existing one, such as:
1. Connect with gas (low pressure readings within 40150);
2. Connect under high and medium pressure without reducing it, using special devices;
3. Connect the pipes, disconnecting them and freeing them from gas.
When performing work, there is an option to turn off the gas in place using a wooden disk, a piece of burlap, clay mass, a rubber chamber.
Connecting a new gas pipeline in a way when you need to turn off the existing one using a rubber chamber is acceptable for a gas pipeline that has a diameter of up to 60 cm. The pressure indicator must be reduced to 150. First you need to check the hand pump for serviceability and chamber tightness properties. It is necessary to install a certain type of pressure gauges and control the pressure.
The procedure is as follows:
1. With the help of an autogen, a hole is cut in the gas pipeline, which works. The hole diameter is about 10 cm.
3. It is necessary to introduce the chamber through the hole made into the channel and fill it with air mass, while ensuring strong contact with the channel walls.
4. A section that is turned off is blown through the hole.
5. Then, it is necessary to crash with a new gas pipeline having a barrier cover.
6. Finally, the chamber must be removed from the working wire, the hole must be sealed, the pressure must be restored, and the tightness properties of the connecting section must be checked.
Attach with a visor
1. The area where it will be connected is cleared of insulating residues.
2. Mark with chalk and cut the end of the pipe together with the steel barrier cap. Then a visor is cut in the extension to a size that ensures the unhindered removal of the disk that is cut out (walls).
3. On the gas pipeline, it is necessary to mark the size of the diameter and its circumference with a small one, which is equal to the diameter of the product that is connected. In the center, weld a rod with a diameter of about 8 mm and a length of about 20 cm. This is necessary in order to remove a piece of pipe that is cut out.
4. Cut out the disc along the marked circle, leaving a small piece of about 5 mm in order to hold the disc. You need to cut down.
5. Put out the gas, cover the hole with a clay mixture along the trajectory of the cutting tool. If the putty dries, then smear again with the already diluted clay mass.
6. The flame is extinguished, the cutting area is cooled down.
8. It is required to insert a wooden disc with a seal into the expansion through the hole. Adjust the canopy to the extension and to the gas structure.
9. Remove the wooden product by knocking out the indented surface of the wall with a hammer, remove it with a rod and firmly press the visor with asbestos. Leakage must be eliminated by applying asbestos.
10. Fix the visor with a wire, the diameter of which is about 3 mm.
11. Blow out the connection well, removing all the mixture.
12. Weld the visor after cleaning it.
13. Adjust the pipes, install a steel gasket on top of the visor and scald with an overlap. The padding is 20 cm larger.
14. Before installation, the gasket is heated with a gas appliance, make a bend with a sledgehammer and fit it to the products so that it overlaps them.
15. Tap the joints, clean and check under working pressure using a soap emulsion. The area where the connection has occurred is cleaned and covered.
16. Install the control tube, fill the ditch.
End connection
1. After cleaning the gas pipe, mark with chalk and cut out the canopy, maintaining a gap of about 50 cm from the steel barrier cover. The size of the visor should not interfere with the installation of the disc. Cut out the disk, cover the gap with a clay mixture. Cool the cutting area.
2. Separate the visor and install a disk inside the gas pipeline, which, in turn, is fixed with a wedge and smeared with clay mass. If the diameter of the product is less than 15 cm, then you need to put a cork in the pipe using bags and clay. Remove the chamfer and fit under the pipe.
3. Mark and cut the ends of both structures and barrier caps. Remove bevels.
4. Make a markup and cut out the connecting node. The length of the node can be determined by breaking both gas pipelines, taking into account allowances for fitting. Install the assembly by grabbing it and weld it at the docking points.
5. Having cooled the disk, take it out and apply a visor using sheet asbestos. Secure it with steel wire, the diameter of which is about 3 mm. Blow out the connected area with gas.
6. Weld the visor, cleaning the chamfer from dirt. Fit, install and weld the steel spacer.
7. It is allowed to use a paste to cover the cracks.
Connecting with a slide-on product
1. Clean the connecting sections from insulating residues.
2. Prepare a pipe for connection (slip-on) with a diameter that is larger than the outer diameter of the gas pipeline to be connected by about 2 cm.
3. Prepare an external extension about 15 cm long, the diameter of which is 1.5 cm larger than the external parameter of the connection pipe. Install the extension, align and attach to the active wire. The axes must match. Having adjusted the expansion, weld.
4. Cut off the barrier cap at the end of the gas line and push on the pipe. Weld special ones to the ends of the pipes, the diameter parameter of which is 3 mm less than the outer parameter of the pipes and expansion.
5. Cut out the wall through the extension, leaving a bridge of about 4 mm. Remove the wall using a pre-welded rod.
6. Extinguish the gas with clay.
7. Push the pipe. At one end, it rests against the wall of the gas pipeline network, which is in operation, and at the other, it moves at least 10 cm onto the product.
8. Cut the window with a hammer and remove it by pushing it into the gas system as far as it will go. Seal the gap between the walls with asbestos cord until the gas stops flowing.
9. Purge with gas until mixtures are completely gone. Heat the ends of the products with a burner and roll them, then overlap them.
Then all procedures are performed in the same way. The walls are removed and the gaps are sealed with an asbestos cord in a gas mask.
how to crash into a gas pipe at home Connection with a coupling is carried out in the following order:
1. Clean the connection area. Prepare the clutch outside diameter which should be 2.5 cm more than the outer parameter of the connection pipes. The length of the product can be determined by the gap between the ends of the products and add 20 cm. The coupling is installed on the ends of the connection pipes.
2. Trim the ends of the products together with the barrier caps. Extinguish the gas with a clay mixture. Weld the rings on the ends. At the end of the pipe and weld both parts of it.
3. Check the coupling by sliding it over the end of the second pipe. Separate the cut ends and barrier caps, followed by pushing the sleeve over the second pipe. Both ends must be overlapped by a coupling of at least 10 cm.
4. Strengthen the gaps between the walls of the products with asbestos cord. It is necessary to seal until the gas stops coming out. After blowing through the pipes, heat the sides of the coupling with a gas appliance and hammer with a hammer until they are completely joined to the pipes. Weld the ends of the coupling.
It is possible to connect by means of a bypass for the period of the installation process regarding the shut-off equipment to the existing gas channel. In addition, under switching conditions, the available continuous gas flow inputs. The diameter parameter of the bypass product is equal to one fifth of the diameter of the products that are connected.
The process is carried out in this order :
1. Make a bypass product, the length of which is equal to the length of the section that is planned to be turned off and add 2 meters to it. Prepare two extensions 5 cm long, their inner diameter should be 1.5 cm larger than the outer diameter parameter of the bypass product.
2. Observing a gap of one meter from the border of the section that is being turned off, mark a circle with a diameter equal to the internal indicator on top of the pipe with chalk. In the center of the circle, weld a rod 0.8 cm long and 20 cm long. Weld extensions to it. Check the installation of the bypass in the extensions.
3. Inside the extensions, cut out the disks in the walls according to the marks, while leaving a 3 mm area. Extinguish the gas with a clay mixture.
4. Knock out the discs and remove them with a rod. Install a bypass from inside the extensions. Docking places to seal with a cord. Attach it to the expansion by means of welding equipment at 3 points.
5. On the marking sections of the pipes, cut out a pair of peaks through a gap of 10 cm from the bypass product. After cooling, separate them. Install the barrier cover through the hole from the inside.
6. After completing the work, remove the barriers, weld the visors, put the disk on the hole.
7. Test seam places, isolate the working area.
Excavation preparatory work and acceptance, insulation measures in the cutting areas and backfilling of the excavations are carried out by the company that built and connected the gas system. Before joining electrochemical means should be disabled. Connecting work under the influence of gas from inside the room is prohibited.
After all the work carried out, the density of the seams is checked with a special device or with an emulsion using pressure. It is also worth bypassing the gas main, marking the work done in the order, writing everything down in the passport. Attach the outfit and scheme to the rest of the documents and save them together.
To open the flange on the connection, devices are used, for example, a copper wedge. It is suitable for products with a small diameter.
If the diameter is more than 30 cm and it is required to open the flange, then fasteners are welded for mounting a jack between them. Can not use hydraulic jack. It is necessary to install gaskets made of wood in order to prevent it from falling. And it is better to fix it on the gas pipeline. During the installation of barrier covers, it is necessary to check the dimensions of the covers and whether they correspond to each other, it is necessary to prepare gaskets, lubricate the bolts.
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