Gas pipeline exit from the ground: requirements and features of arrangement of the exit node

Each stage of connecting a house to a centralized gas pipeline must be carried out in accordance with regulatory documents and installation rules, therefore only representatives of gas services have access to the work.

Let us dwell on one of the key stages of the equipment - the basement input. This term refers to a monolithic connection of two gas pipeline elements: a polyethylene pipe, which is laid in the ground, and a steel pipe, most often an external one.

Gas workers must also select parts and arrange the exit of the gas pipeline from the ground, but the owner of the house can control both the quality of the materials used and compliance with installation standards. And our article will help him with this, in which the regulatory regulations are analyzed in detail, diagrams and examples of base input are presented.

The main guideline is regulatory documentation

In the future, during scheduled inspections or in the event of an emergency, regulatory authorities will carefully inspect all components, starting from inserts into the central pipe and ending with connecting a gas boiler, stove or oven. And the first thing they will pay attention to is whether the installation method is chosen correctly - above-ground or underground.

A more acceptable, but also expensive way to supply fuel to the house is underground. It is practiced if the pipe is not subsequently affected by factors such as seismic activity, groundwater, or road surfaces crossing the path.

The basement input is an element of underground installation, therefore, further we will only talk about it.

But the integrity and correct output equipment gas pipe from the ground are important not only because of the risk of receiving a large fine during an inspection. The main thing is to ensure the safety of the residents of the house and everyone nearby.

Any faulty equipment threatens a serious accident on the gas pipeline. In addition, if the basement inlet is not properly designed, a gas leak may occur, and this will result in additional expenses from the family budget.

The gas line is brought out from underground to the outside directly near the wall of the building to ensure the shortest path to the end point - the boiler, which is located in the kitchen or in a separate room

When laying main pipes, installers are guided by the provisions set out in Russian regulatory documents. For example, in SNiP 2.04.08-87* all the nuances of installing polyethylene pipes, preferable for private use, as well as the requirements for their laying routes are considered.

The depth of laying the gas pipeline is also regulated here - 0.8 m. The exception is for territories where traffic is not expected - 0.6 m. These data must be taken into account when choosing the size of equipment for installing a gas pipeline out of the ground, although factory products are usually adjusted to standard scale.

It is undesirable for underground water to be present near the installation site of the input unit. If they still exist, measures must be taken to prevent deformation or floating of the polyethylene pipe.

Specific information about underground gas pipelines can be found in SNiP 42-01-2002. It contains useful materials on the use of cases - special protective elements, as well as on the conditions for using polyethylene pipes.

It is interesting that two or even more gas lines can be located in one trench, but in such a way that it is possible to freely access each of them during repairs

While laying pipes, workers may encounter the gas pipeline intersecting with other utility networks. This does not cause any difficulties, since the permissible distance between the networks is only 20 cm.

All stages of construction, from project development to commissioning, must be carried out in accordance with the standards SNiP 3.02.01-87, PB 12-529-03 And SP 62.13330-2011.

Features of gas pipeline outlet equipment

You cannot independently manufacture parts for the base input equipment.

They are produced in the factory from materials that meet the requirements of GOST:

• straight-seam steel pipes (10705-80 or 3262-75);
• seamless pipes (8734-75 or 8732-78);
• polyethylene pipes (50838-95).

It should be remembered that all connections of the inlet to the gas pipeline must be permanent - both those located underground and those located outside. Steel elements are connected by welding and insulated. And although low pressure gas is supplied to the residential sector, adapter parts are often designed to supply medium or high pressure fuel.

Read more about pressure in the gas pipeline Further.

According to the installation rules, the length of the above-ground part of the main, placed in a case or simply insulated, must exceed the height of stable snow cover by 0.2 m (according to average indicators)

The length of the lower part depends on the installation conditions and depth of the gas pipeline.But you need to remember that the trench is never laid below the base of the foundation of the house. It turns out that all the details of the gas pipeline entry into the ground should be located in the segment from the bottom point of the foundation to the windows of the 1st floor.

The polyethylene-steel connection is most often located on a more protected horizontal area, which is located in the ground. In this case, one of the requirements is a temperature not lower than -20°C

The correct temperature conditions can be ensured by insulating the polyethylene pipe and permanent connection. In the southern regions, thermal insulation is not needed, but it is necessary to eliminate mechanical loads on the connecting unit.

Types of base inputs

There are three types of gas pipeline exit points from the ground, as well as their options - with or without a case. All presented designs are intended for installation in places where the gas main exits from the ground, and are suitable for gasification of residential buildings, that is, low-pressure networks.

Let's take a closer look at how they differ.

Option #1 – L-shaped

This is the most common type of design, shaped like the letter “L” and reminiscent of a poker. It is usually made from two types of pipes - steel and polyethylene. The steel part is cold bent, without welds, and protected from corrosion by extruded polyethylene or other moisture-resistant material.

Diagram of the central heating system indicating the material of manufacture and methods of connecting the structure to the pipes. The monolithic polyethylene-steel assembly is located on a horizontal, underground section of the product

The location of the permanent connection underground, on a horizontal section, protects it from freezing in frosts typical of northern regions with a harsh climate.

Products are manufactured in factories, where they are covered with a layer of insulation. Already on site, the connecting nodes are protected with adhesive polymer tapes, the layer thickness is at least 1.8 mm

In addition to conventional designs, products with transitions are produced. This is a metal part with a standard diameter of 25 or 32 mm, made by rolling and secured by welding.

Option #2 – i-shaped

The material for the production of i-shaped structures is the same as for the production of L-shaped analogues - polyethylene and steel pipes of GOST standards. They are also intended to ensure gas supply to residential buildings - dachas, cottages.

A special feature of the products is the location of the polyethylene-steel transition. It is not located on the horizontal part, like the alternative L-shaped product, but on the vertical part, but underground.

Scheme of i-shaped base input. Due to the location of the permanent connection on the vertical part, the product is suitable for installation in any type of soil

To protect the connection, thermal insulation and a metal case are used. i-shaped structures, even the most insulated and insulated, have temperature restrictions. They are installed in areas where the air temperature in winter does not drop below -15°C.

Residential gas connections are usually low pressure, but the i-inlet is suitable for medium/high pressure fuel supply.

Option #3 - straight

The main difference between the direct exit of a gas pipe from the ground is that it consists entirely of polyethylene, which ensures free bending. The second feature is its use only for the residential sector, since it cannot withstand the supply of medium and high pressure fuel.

The polyethylene-steel transition is located at the top, on the vertical part of the product. To protect against mechanical damage and exposure to atmospheric agents, it is enclosed in a durable metal case.

Direct inputs are located near residential buildings, in close proximity to the connection point of household appliances - boilers, stoves, ovens.

Example of practical implementation

For a more thorough understanding of the process of introducing gas into a house, we suggest considering an example - gasification of a dacha.

The gas line runs near a residential building, just 10 meters from the fence. When collecting documents, it turned out that the soil is ideal for laying the pipe and no additional measures are required to strengthen the pipeline

The house is located on a plot with a vegetable garden and trees, so when digging a trench we had to “loop” between pine and apple trees.

In total, the distance from the tie-in to the central highway to the basement input is 70 m. The depth of the trench is 1 m, width is 35-40 cm. This is enough to lay a pipe, and in case of repair, carry out replacement measures.

Next, the main line runs along the wall and is divided into two branches, one of which goes to the gas stove, the second to the household heating boiler.

The design of the basement inlet from the presented example is an example of a gas pipeline exiting the ground in a case, a protective metal cover.

There is an article on our website where we examined the process in detail.asification of a private house. Recommended reading.

What types of cases are used?

Gas workers themselves determine which type of base inlet is optimal for specific conditions; they also choose the protective case and method of its installation.

Depending on the configuration of the product, it is placed in one of the cases:

• flexible split made of polyethylene;
• metal.

Both types are released under basic conditions.

To make an elastic case, use a polyethylene pipe cut in half lengthwise. During installation, it is glued with sealant, wrapped along the entire length with adhesive tape and clamped with metal clamps.

To prevent debris or water from getting inside the protective cover, seal it at the ends and then install plugs.

The metal case is made of steel and mounted on the product during the installation of the input into the house. The cavity between the gas pipe and the cover is filled with either spun flax or rope, and then sealed with mastic at both ends by about 20 cm.

The outer part is coated with a primer and yellow metal enamel in two layers - according to GOST 6465.Such protection should protect the metal from corrosion and rapid wear.

Both types of cases should maximally protect the polyethylene-steel transition from external influences, as well as ensure reliability and stability of the structure.

Recommendations for pipe protection

Typically, representatives of organizations installing gas pipelines into a house act strictly according to the instructions. Any violation of installation rules is fraught with big troubles for home owners and penalties for gas workers.

You need to enter into an agreement to connect your house to the CGM with the supplier company or representatives of the organization servicing the main gas supply in your area

However, sometimes craftsmen make mistakes, so we recommend that owners of cottages and country houses closely monitor the work of specialists.

Here are some useful tips:

1. If you know for sure that your territory is characterized by heaving soils, require the installation of a basement input in a case.
2. If there is a risk of flooding by surface water through the backfill soil, then you need to build a blind area with a 3-centimeter slope. For structures without a casing, the blind area should rise above the ground by 0.15 m.
3. To protect the structure inside the case, plugs are installed. The top one is made in a mushroom shape.
4. The case plugs must have the necessary characteristics of moisture resistance and resistance to UV radiation.
5. The vertical part of the input should be located perpendicular to the horizontal, without slope.
6. After installation, the case should not sag; if necessary, use special supports.

Only non-heaving soils, sifted and dense, without large inclusions, are suitable for backfilling the inlet structure.Every 25-30 cm of backfill is carefully compacted to fill the sinuses.

For connecting gas to the house Not only ready-made factory base inputs are used. It is connected to the internal main line with pipe sections, which often need to be bent. To do this, gas workers always have special equipment and special tools with them.

The gas service vehicle is equipped with the necessary tools: a universal pipe bender for any diameter, welding equipment, a workbench with a vice, coils with polyethylene pipes and tapes for sealing

Typically, workers use their own material - high-quality and tested at other sites, but the owner has the right to request certificates for materials and check whether they correspond to what is specified in the project.

Conclusions and useful video on the topic

Overview of the base entry – from the outside and from the inside:

Injecting gas into the house from a gas tank:

Measures for introducing a gas pipeline into the house:

Installation of a basement inlet is just one of the stages of connecting a house to a main line supplying natural fuel, but it must be taken seriously and responsibly. We recommend concluding an agreement with a service company that will install, connect, test, and subsequently monitor the operation of the gas pipeline.

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