Gas supply to the settlement is carried out through a distribution network. The delivery scheme consists in the passage of fuel through gas pipelines to equipment installed in a residential area in accordance with accepted standards and requirements of special control services.
Gas goes through several stages of transportation:
- from the place of extraction to the distribution point;
- from the conversion point to the city gas network.
The gas supply network for a populated area consists of a certain number of distributed points, stations and receivers for monitoring the level and pressure indicators.
The entire network is an ordered system in which intra-yard and intra-house schemes for laying gas pipes are involved.
For the installation of any gas pipeline, special-purpose pipes are used. In apartment and private houses, steel types are used, they are characterized as high-strength. They are selected according to the type of pressure level of the city network:
- 0.05 kg s/cm 2 for low pressure;
- 0.05 to 3.0 kgf / cm 2 average pressure;
- 3 to 6 kgf / cm 2 — high pressure.
Pros and cons of steel gas pipes
Steel products have high physical properties. Despite this, the application reveals shortcomings that can affect the service life and operating conditions of gas pipes in apartment buildings.
|high level strength
|complications during the dismantling of large areas
|suitable for indoor and outdoor use
|inability to bend the product in the required place
|suitable for above ground and underground laying
|a large number of elements
|ensure uninterrupted supply due to tightness and reliability of welding seams
|light thin-walled products are prone to condensation
To facilitate installation and construction work, pipes made of polymeric materials are put into operation in some sections of gas pipelines. They have their own advantages and disadvantages. They are identified when compared with steel structures of this type:
Unlike steel pipes, polypropylene pipes are easy to install. The service life of such pipes can reach up to 80 years. They can only be applied if the gas pressure does not exceed 1.2 MPa.
The diameter of polypropylene pipes used for gas wire varies from 20 to 400 mm. Pipes are characterized by increased throughput compared to steel pipes.
The main disadvantages are:
- deformation when heated above 80 degrees;
- damage during seismic activity or low temperatures;
- destruction of the structure under the influence of ultraviolet rays.
When using gas pipes in residential premises, the following operating rules must be observed:
- laying gas pipes is not possible in air ducts, ventilation shafts in apartments;
- pipes should not block door or window openings;
- access to pipes cannot be blocked by wall panels, decor of a complex degree of dismantling;
- the distance to the floor surface from the gas pipe must be at least 200 cm;
- installation is carried out in residential premises, the height of which is not lower than 220 cm;
- finishing of ceilings and walls in places of access to gas pipes should not contain combustible materials;
- welding is used for connection, an open approach for inspection and access is provided at the connectors;
- the location of the pipes relative to the electrical wiring must meet the pre-established safety requirements in a particular residential area;
- pipe connections are provided for kitchens equipped with gas stoves that meet safety standards;
- the distance from the plates to the walls must be at least 7 cm;
- residential premises in which gas stoves, gas water heaters or boilers for heating are installed must have ventilation outlets;
- the gas pipeline system should not be located near cooling appliances;
- when fixing the gas pipe on the wall, specially provided devices are used.
According to SNiP (a standard established for construction organizations), there are requirements for the physical properties of the gas pipeline and the dimensions of the structures:
- the thickness of the wall of the wired product should be about 3 mm for laying underground, the wall thickness for laying above ground — at least 2 mm;
- the diameter of steel products for the gas pipeline can be from 15 to 100 mm;
- the throughput of such products ranges from 3 to 12 atmospheres, the indicator depends on the place of passage.
It is customary to call pipes dimensional, reaching 12 m in length. Non-dimensional pipes are those that exceed this level in length.
There are pre-established standards that calculate the service life of steel products for conducting gas. Steel structures have an approximate period of 30 years. The period may be affected by the presence of external factors. Special conditions create risks of reduced service life.
Signs by which you can determine that the pipes need to be replaced
Before proceeding to the replacement process, utilities conduct appropriate examinations and measurements. Based on the actions taken, protocols are drawn up, and gas pipeline products are prepared for replacement.
Based on the results of the check, a replacement is necessary if:
- there was a thinning of the walls above the norm;
- there has been a change in welding joints;
- there is a gas leak according to meter readings.
Repair of gas pipes
Repair of structures involves their replacement: partially or completely. Complete replacement is carried out by mobile teams, they remove the damaged sections of the main passage to the common house, then — if necessary.
Replacing a partial type in an apartment building involves cutting sections and placing a new part using a welded joint. These actions include compliance with safety rules:
- The gas supply is shut off.
- From the area that is being replaced, remove the remaining gas in accordance with the rules for the safe handling of hazardous objects.
- After trimming, a new section is welded.
- Tests are being carried out to analyze the integrity of the replaced section.
- The gas is started after the necessary purge.
Replacement of gas equipment should not be done independently. This is a complex and technically dangerous process that specialists are able to carry out. After the change, the information is entered into a special technical passport, which will indicate the work, the occurrence of nuances and dates.
In the presence of a gas supply system, consumers must follow the rules that help extend the life of structures and prevent difficult situations:
- timely inspection and inspection of gas pipes;
- the correct sequence of switching on the equipment;
- checking equipment if a gas leak is suspected.
Minimal doubts about the condition of gas equipment require the immediate call of utility service specialists. When using domestic gas, it is prohibited:
- tie up gas pipelines with ropes;
- reinstall the equipment yourself;
- check for leaks with matches or lighters;
- bend or bunch the hoses that connect the system to the stove.
Compliance with the rules is necessary to avoid dangerous situations.