Categories of gas pipelines by pressure. Classification of gas pipelines: by type of gas and pressure

The gas supply industry includes many components, these are:

highways and distribution networks, laid separately or mixed;
gas distribution stations, regulatory installations and points;
automated systems.

Blue fuel is used everywhere, the quality of life of the population depends on it, therefore gas industry equipment must ensure trouble-free operation and uninterrupted supply to all consumers.

We recommend: What other types of gas pressure exist?

What gas is used in residential buildings

Natural gas is a conditional concept that is used for a flammable gaseous mixture extracted from the subsoil and delivered to thermal energy consumers in liquid form.

The composition is varied, but methane always predominates (from 80 to 100%). In addition, natural gas includes: ethane, propane, butane, water vapor, hydrogen, hydrogen sulfide, carbon dioxide, nitrogen, and helium. An indicator of the quality of natural gas is the amount of methane. All other components of natural gas are unpleasant additives that create polluting emissions and destroy pipes. Natural gas for residential buildings is not recognized by the senses in any way, so strong-smelling gases are added to it - odorants, which perform a signaling function.

The difference between two measured indicators is called differential pressure (pressure differentialis) - difference or difference. It is used to determine the pressure drop when using any equipment. Typically on compressed gas or air purification filters. This type has nothing to do with absolute value or excess.

All of the above types of measured quantities are used in the operation and design of gas pipelines and pipelines of industrial and private facilities, automotive gas equipment systems equipped with absolute indicator sensors (DAS). Therefore, for general development it will not hurt to know these concepts, but it makes no sense to go into detail, unless of course you want to understand the physics of the processes.

To determine the required distance from the gas pipe, after developing a residential building project, citizens of the Russian Federation apply for the appropriate permit (approval) from the local gas distribution organization. For a definite answer, you need to know the type of gas pipeline and what pressure is used when supplying it. If there is no data on the type of laying and the pressure in the pipes, it is impossible to give an unambiguous answer.

Gas distribution station

SNiP 42-01-2002 is one of the natural results of the Federal Law of the Russian Federation “On Technical Regulation” No. 184, adopted in December 2002. In November 2008, the Government of the Russian Federation adopted Resolution No. 858, according to which the current sets of rules were developed and approved. This SP was approved at the legislative level in an updated version and was named SP 62.13330.2011.

The most affordable type of fuel has become widespread and has become a publicly available energy resource. Its widespread use has led to the urgent need to develop regulatory documents in which the permitted distances can be found.

Compressor station

Since 2010, SNiP registered by Rosstandart:

are legislative documents, compliance with which is mandatory;
checked by supervisory organizations designed to ensure the safety of such structures;
may be the basis for a decision in a lawsuit;
are recognized as a significant reason for imposing an administrative penalty upon violation.

SP 62.13330.2011 regulates the distances that must be observed depending on the type of laying of the main gas pipeline or its branches and the pressure of liquid fuel in the pipes.

Near a residential building

If gas is supplied in cylinders, only the prescribed fire safety standards must be observed. More economical and volumetric transportation in pipes provides for differentiated requirements for different types of supplies and pressure levels during their implementation.

The gas pipeline security zone is one of the territories with a special land use regime. At the same time, there is a sanitary protection zone for these objects, the rules for the arrangement of which are established by SanPiN 2.2.1/2.1.1.1200-03.

According to Appendix 1 to these rules, the sanitary zone of a high-pressure gas pipeline depends on the pressure in the pipe, its diameter, as well as the type of buildings and structures in relation to which the distance is calculated.

The smallest sanitary zone from rivers and other bodies of water, as well as water intakes and irrigation structures, is 25 m for main gas pipelines of any diameter and type.

The largest protective zone of a high-pressure gas pipeline is necessary if we are talking about a class 1 gas pipeline with a diameter of 1200 mm in cities, holiday villages and other crowded places. In this case, the length of the sanitary zone reaches 250 m.

More detailed data on sanitary protection zones of natural and liquefied gas main gas pipelines can be found in the corresponding tables of this document. For highways transporting liquefied gas, sanitary zones have been significantly increased.

The gas pipeline is an important element of the gas supply system, since 70.80% of all capital investments are spent on its construction. At the same time, of the total length of gas distribution networks, 80% are low-pressure gas pipelines and 20% are medium- and high-pressure gas pipelines.

Security zones of other networks

It must be taken into account that water supply, sewerage and other communications also have their own sanitary protection zones. They are also called security guards. Yes, the gas pipeline security area already takes this into account.

Underground heating network

However, before carrying out any work, it is important to take into account such parameters for each network so that nothing is left unattended. And so that in the end it does not turn out that some network does not fit in relation to others

It is important to take into account that the sanitary zone near certain communications must be installed in each direction from the axis. For each such system with a security zone there is its own SNiP (SP) table with standards for distances to certain objects

You should always be guided by building codes and regulations regarding how many meters you should retreat in each direction.

Nuances of security zones

It is also important to consider that a main gas pipeline is a completely different story than a gas distribution station or hub. And the security zone in high-pressure routes reaches 50 meters

Size of the main pipe protection zone

As a rule, these are pipes of large diameter. With such a width, in the event of an accident, the leak will be much larger and more intense. This is due to the volume of the substance inside and the speed of its transportation.

The rules for the location of security zones apply everywhere, both in Moscow and in the Nizhny Novgorod region. After all, according to experts, this pipeline has the status of a hazardous production facility (hazardous production facility).

Overhead gas pipeline

And it’s not just about the serious legal consequences for anyone who violates the protection zone. Judging by the practice of decades, if gas communications are laid incorrectly, there is a possibility of encountering risks that will pose a threat to the lives of others.

Types of gas pipelines

Hydrocarbon gases are recognized in the world community as a more promising type of raw material than oil, and much more productive than coal. Transportation of LPG - liquefied hydrocarbon gases - requires special conditions, as well as storage. Sometimes they are called, depending on their origin, LPG (petroleum) or LNG (natural). Today, all three abbreviations are understood to mean the same thing as LPG, but these mixtures sometimes have significant differences in their constituents, suggesting the need to develop separate standards for LNG.

Gas pipeline valve

Due to the potential for explosion hazards, special rules apply to the installation of networks. Exist:

special SP 62.13330.2011 “Gas distribution systems” (revised and expanded edition of SNiP 42-01-2002);
auxiliary table (B.1*), which indicates the minimum distances resulting from the set of rules;
FNiP “Safety Rules for Facilities Using Liquefied Hydrocarbon Gases” (PBs were approved by Order No. 558 dated November 21, 2013);
recently adopted GOST 9.602-2016 “Unified system of protection against corrosion and aging. Underground structures”, related to the protection of gas distribution systems.

Near the city

The distance from residential and public buildings to the gas pipeline can be found in the “Rules for the protection of gas distribution networks”, approved by Decree of the Government of the Russian Federation of November 20, 2000 No. 878. The basic requirements for any pipelines are reliability and safety in operation.

Much depends on the ability of the entire complex to ensure industrial safety rules at any stage, as well as the ability to shut down individual sections for repair and safety work.

Installed to move raw materials over long distances. They are considered dangerous structures because gas flows through them under high pressure. The first category assumes up to 10 MPa, the second – up to 2.5 MPa. To maintain high pressure along the transportation route, gas compressor stations are needed. Gas distribution stations reduce the pressure to supply it to the hydraulic fracturing unit, from where the fuel is delivered directly to the consumer.

Gas distribution pipelines are laid from gas distribution stations to the consumer in compliance with the necessary safety rules. This means that they support low, high or medium gas pressure. The permissible distance from the gas pipeline to the foundation of the building (structure) is regulated taking into account the requirements of the set of rules.

The need to maintain a certain distance is dictated by the number of outlets, single-stage or multi-stage, gas pressure at the outlet (low, medium - from 5 kPa to 0.3 MPa, high - from 0.3 to 1.2 MPa).

The influence of hell vibrations on the human body

Since balance is achieved through the fluids of our body - blood, lymph, tissue fluid - atmospheric pressure directly affects blood pressure. Changes in one lead to imbalance in the other.

Low barometer reading

A decrease in pressure, which is observed when rising to a height, can lead to the following consequences:

labored breathing;
low heart rate;
fatigue, drowsiness;
apathy;
low blood pressure;
headache;
attacks of dizziness;
nausea or vomiting;
digestive system disorders;
problems with concentration.

When air pressure decreases, people with respiratory pathologies and usually low blood pressure are at risk. Usually their condition gets worse under such conditions. If a person does not feel changes, such fluctuations can be considered normal for him.

High barometer reading

Fluctuations upward in the mercury column are observed when descending into mines, caves or other lowlands.

Discomfort will differ from low blood pressure:

ringing in the ears, stuffy ears;
pulsation in the temples and neck;
increased blood pressure;
increased heart rate;
rush of blood to human skin, redness;
spots before the eyes;
headache:
dizziness;
nausea or vomiting.

Note!

With elevated atmospheric pressure, heart attacks and strokes often occur. People prone to weather dependence should monitor weather conditions and on days of high blood pressure not overload their body with stress or physical activity.

At-risk groups

If the mercury moves even one division in 2-3 hours, weather-dependent people will feel it. Fatigue, drowsiness, nausea and other unpleasant or even painful symptoms will immediately manifest themselves. Who are classified as people dependent on changes in atmospheric pressure?

Various injuries, diseases or congenital pathologies are the cause of such unpleasant symptoms. So the people who suffer from weather dependence first of all are:

with high or low blood pressure;
with respiratory pathologies - asthma, bronchitis, pleurisy, chest injuries, sinusitis, sinusitis;
with musculoskeletal disorders - arthrosis, osteochondrosis, old injuries;
with ear diseases;
after traumatic brain injury or with increased intracranial pressure.

What to do to relieve symptoms

It is very important for middle-aged and older people to take care of their health. Cyclones and anticyclones can cause serious consequences

To prevent stroke and heart attack, as well as alleviate unpleasant symptoms, you should listen to some tips:

Consultation with your doctor. He, based on the patient’s characteristics, will be able to select the right drug or, for example, treatment in an oxygen pressure chamber.
Regularly checking weather conditions. It is necessary to free such days from stress at work and at home.
Correct sleep schedule. Sleep duration should be at least 7 hours. When the weather changes, it is better to go to bed earlier.
Proper nutrition. The menu should be balanced and complete. Eliminate fatty foods, but consume foods containing omega 3-6-9 acids.
Walks in the fresh air (preferably in the evening).
Moderate physical activity.
Reduced stress levels.

Rules and regulations

Gas distribution station

Compressor station

Since 2010, SNiP registered by Rosstandart:

are legislative documents, compliance with which is mandatory;
checked by supervisory organizations designed to ensure the safety of such structures;
may be the basis for a decision in a lawsuit;
are recognized as a significant reason for imposing an administrative penalty upon violation.

SP 62.13330.2011 regulates the distances that must be observed depending on the type of laying of the main gas pipeline or its branches and the pressure of liquid fuel in the pipes.

Near a residential building

Connection diagram

How does the fuel supply turn off?

Any system requires periodic maintenance, which includes replacing certain parts and monitoring the condition of components and assemblies. To make repairs easy and safe, the gas supply must be turned off during work. To ensure a quick shutdown of fuel flow, industrial and household networks are equipped with special valves, otherwise called plug valves.

Disconnection devices are usually installed outside the building; a protective cabinet may be used for this purpose. If you need to disconnect the building from the gas supply, simply turn the valve. Valves are usually installed:

At gas distribution points at the points of entry and exit of pipes;
When dividing highways into local city networks;
At the beginning of an object blocking the path - for example, in front of a railway, highway or pond.

On external gas pipelines, shut-off devices are mounted in special wells. Lens compensators are installed next to the devices. These devices are used to monitor gas levels, as well as to simplify work with shut-off valves. Installation of wells is permitted at a distance of at least 2 meters from the nearest object.

On residential buildings and other structures, valves are located on the external wall, and a distance of at least 1 meter from the openings is maintained. The number of shut-off devices does not depend on the pressure in the system, the length of the pipes or the degree of branching of the network. The presence of each device must be economically justified; you should try to get by with the minimum number for the facility.

Use of gas pipelines

A gas overpass is a unified gas supply and distribution system that can be implemented in high, medium, and low pressure networks (table for classification of gas pipelines by gas pressure). The construction of gas pipelines accounts for up to 80% of capital investments in the arrangement of the gasification system.

At the same time, various types and types of low-pressure gas pipelines account for 80 out of 100 m of laying (80% of the length of the gas supply network). The remaining 20% are medium and high pressure pipelines.

Medium pressure gas pipelines are gas pipelines with a working gas pressure of over 0.005 MPa to 0.3 MPa.
High pressure gas pipelines are gas pipelines with a working gas pressure of over 0.3 MPa.

Sewage pipelines

Sewage pipelines are used for the removal and discharge of wastewater outside industrial facilities and populated areas.

In pressure sewer pipelines, the medium moves under excess pressure, in non-pressure pipelines - by gravity.

Sewage systems according to SNiP 2.04.01-85 are classified:

Household - used to move wastewater from sanitary installations (toilets, bathtubs, washbasins, swimming pools, etc.);
Industrial - used for the disposal of various types of industrial wastewater;
Combined - used to move domestic and industrial wastewater “together”. If possible and permitted, their joint transportation and subsequent cleaning;
Internal drains - used to remove rain and melt water from the roof of a building.

Source

Pressure classification

In all cases, pressure remains one of the defining characteristics of the overpass. The rules of its operation, as well as the reliability, safety and power of the entire system depend on what type of gas pipelines the network belongs to.

As for the purpose of networks in the table for classifying gas pipelines by pressure, then:

High-pressure gas pipelines serve industrial enterprises and gas control points of medium-pressure pipelines.
The medium-pressure gas pipeline supplies gas to utilities and small production facilities (as well as low-pressure systems).
Low pressure overpasses serve the residential segment and utilities.

According to accepted standards for the design of gas supply facilities for natural gas and LPG, gas pipelines are divided into several categories depending on the pressure of the transported gas. All technical decisions made at the stages of design, reconstruction, technical re-equipment, construction and repair of gas supply facilities (gas distribution and gas consumption networks) depend on the correct classification of the gas pipeline and the correct choice of gas pipeline category.

The classification of gas pipelines given in these documents is basically the same, with the exception that the “Technical Regulations on the Safety of Gas Distribution and Gas Consumption Networks” contains a high-pressure gas pipeline of category 1a with pressure over 1.2 MPa.

In this case, clause 4.3. from the joint venture is advisory in nature, and the “Technical Regulations on the Safety of Gas Distribution and Gas Consumption Networks” are mandatory in full.

Therefore, it is customary to use the classification from TR “Technical Regulations on the Safety of Gas Distribution and Gas Consumption Networks” for natural gas pipelines:

High-pressure gas pipelines of category 1a - gas pressure in the gas pipeline is over 1.2 MPa (12 kgf/cm²). Gas pipelines with this pressure are designed to supply gas to combined cycle and turbine plants on the territory of thermal power plants. Most often, such enterprises receive gas through high-pressure gas pipelines of category 1. On the territory of the enterprises themselves, booster compressor stations are provided to increase gas pressure;
High-pressure gas pipelines of category 1 - gas pressure in the gas pipeline is over 0.6 MPa (6 kgf/cm²), but not more than 1.2 MPa (12 kgf/cm²), inclusive. A gas pipeline with such pressure is used as an inter-settlement pipeline, as well as for gas supply to industrial enterprises where high-pressure gas is needed for technological needs (for example, see high-pressure gas pipeline of category 1a). The working documentation uses the symbol for high-pressure gas pipelines of category 1 (GOST 21.609-2014) - G4;
High-pressure gas pipelines of category 2 - gas pressure in the gas pipeline is over 0.3 MPa (3 kgf/cm²), but not more than 0.6 MPa (6 kgf/cm²), inclusive. Gas pipelines with such pressure are designed to supply gas within a populated area to various industrial consumers (on-site gas pipelines of industrial enterprises), as well as to gas reduction points, from which gas supply is provided to consumers in administrative, public and residential buildings. It is allowed to lay gas pipelines with this pressure inside production premises. The working documentation uses the symbol for high-pressure gas pipelines of category 2 (GOST 21.609-2014) - G3;
Medium pressure gas pipelines - gas pressure in the gas pipeline is over 0.005 MPa (0.05 kgf/cm²), but not more than 0.3 MPa (3 kgf/cm²), inclusive. Gas pipelines with such pressure are designed to supply gas within a populated area to various industrial consumers, as well as to gas reduction points, from which gas supply is provided to consumers in administrative, public and residential buildings. In some cases, it is allowed to supply a gas pipeline with such pressure to cabinet reduction points located on the walls of administrative, public and residential buildings. It is allowed to lay gas pipelines with this pressure inside production premises. The working documentation uses the symbol for medium pressure gas pipelines (GOST 21.609-2014) - G2;
Low pressure gas pipelines - gas pressure in the gas pipeline up to 0.005 MPa (0.05 kgf/cm²) inclusive. With the help of such gas pipelines, gas is supplied directly to the population for household appliances or enterprises in the household sector. The working documentation uses the symbol for low pressure gas pipelines (GOST 21.609-2014) - G1.

The following technical solutions depend on the selected category of gas pipeline and gas pressure in gas pipelines:

selection of gas pipeline pipe material (steel, polyethylene, copper, etc. pipes);
method of laying gas pipelines (external or internal; above-ground, underground or above-ground; on separate supports/overpasses or on the walls of buildings);
standard distances from gas pipelines to buildings and structures (for above-ground/ground gas pipelines and for underground gas pipelines);
by calculating the diameter of the gas pipeline (more details);
requirements for testing gas pipelines after installation;
and many other solutions.

Help: The website has an online pipe assortment. The program allows you to view the data of the pipes from which pipelines are laid, including gas pipelines.

Due to the fact that many sources on the Internet confuse the concept of the security zone of gas pipelines (gas distribution and gas consumption networks) and the standard distance from gas pipelines to buildings and structures, I would like to separately note that the security zones of gas pipelines do not depend on the gas pressure in the gas pipeline (security zones high, medium and low pressure gas pipelines coincide) and are determined by the Rules for the protection of gas distribution networks. More details in the video in the Videos section.

The website implements online hydraulic calculation of gas pipelines “HYDRAULIC CALCULATION OF PIPELINES (GAS PIPELINES)”. During the calculation process, the category of the gas pipeline is automatically determined depending on the pressure. You can use it to determine which category your gas pipeline belongs to.

Classification of gas pipelines by pressure	Gas pressure, MPa	Hazard class of hazardous facilities (see note)
high category 1a	above 1.2 (for LPG above 1.6)	Hazard class 2
high category 1	from 0.6 to 1.2 incl.	Hazard class 3
high category 2	from 0.3 to 0.6 incl.	Hazard class 3
medium pressure	from 0.005 to 0.3 incl.	Hazard class 3
low pressure	below 0.005	see below

The gas consumption and gas distribution network falls under the criteria of a hazardous production facility if there is equipment operating under a pressure of natural or liquefied petroleum gas above 0.005 MPa, even if the hazardous production facility contains equipment operating under a pressure of natural or liquefied petroleum gas of 0.005 MPa or lower.

Hazardous production facilities do not include gas supply systems of enterprises that do not have areas and equipment with gas pressure above 0.005 MPa.

Note:

If the gas distribution and gas consumption network includes networks of different pressures, the hazard class of the hazardous facility is determined by the maximum pressure in the network.
For gas distribution and gas consumption networks located on lands of specially protected natural areas, the continental shelf of the Russian Federation, in internal sea waters, in the territorial sea or the adjacent zone of the Russian Federation, on an artificial land plot created on a water body located in federal ownership, more than high hazard class;
Read more about identifying a hazardous production facility (HPF).

In the original version of “SP 62.13330.2011 * Gas distribution systems” in 2011-2012, there was an attempt to introduce a different classification of gas pipelines, namely, medium pressure gas pipelines belonged to category 3 and low pressure gas pipelines belonged to category 4 gas pipelines.

Later, changes No. 1 to this set of rules were an attempt to radically change the classification in terms of medium and low pressure gas pipelines:

“SP 62.13330.2011* Gas Distribution Systems” again made changes (Changes No. 2 of 2016) to the classification of gas pipelines and eliminated contradictions with the “Technical Regulations on the Safety of Gas Distribution and Gas Consumption Networks”!

Compressor stations

Compressor stations are needed to maintain pressure levels and transport the required volume of gas through the pipeline. There the gas undergoes purification from foreign substances, drying, increasing pressure and cooling. After undergoing processing, the gas under a certain pressure enters the gas pipeline.

Compressor stations, along with gas distribution stations and points, are part of the complex of above-ground structures of the main gas pipeline.

Compressor units are transported to the construction site in the form of blocks completely ready for assembly. They are being built at a distance of approximately 125 kilometers from each other.

The compressor complex includes:

the station itself;
repair and maintenance and service and maintenance units;
the area where dust collectors are located;
cooling tower;
water container;
oil farming;
gas-cooled devices, etc.

A residential village is usually built next to the compression plant.

Such stations are considered a separate type of technogenic influence on the natural environment. Studies have shown that in the area of compressor installations, the concentration of nitrogen oxide in the air exceeds the maximum permissible level.

They are also a powerful source of noise. Scientists have found that prolonged exposure to noise from a compressor station causes disturbances in the human body, and, as a result, causes various diseases and can lead to disability. In addition, noise forces animals and birds to move to new habitats, which leads to their overcrowding and a decrease in the productivity of hunting grounds.

Classification of gas pipelines by installation method

Here you can see 2 types - underground and aboveground gas pipelines.

Underground gas pipelines are external; they are laid below ground level or along its surface in an embankment. The pressure in such a gas pipeline can be any. The construction of such gas pipelines is regulated by the provisions of SNiP; distances from other underground communications must be strictly observed. Pipe material: steel or polyethylene. Steel pipes must be coated with a layer of insulation to protect against corrosion. Repair and maintenance of underground gas pipelines are carried out by operational services.

Laying an underground gas pipeline

Advantages and disadvantages

An underground gas pipeline is constructed underground. Its installation is more expensive due to the complexity of the work. It is also necessary to carry out engineering-geological and geodetic surveys. The steel pipe must have electrochemical protection against stray currents. A polyethylene pipe does not need this. But the big plus of underground installation is that the pipe underground is better protected from external influences, thereby increasing its durability. Also, an underground gas pipeline is much safer than an above-ground one.

Such gas pipelines are installed only from metal pipes that comply with GOST standards

What does the gas transportation complex consist of?

The gas supply system includes an extensive network of highways and gas pipelines, distribution stations, auxiliary buildings and structures, as well as technical instruments for monitoring and adjusting the properties and quality of fuel. Industrial enterprises, farms, public utilities, private and apartment buildings - each facility needs a certain amount of gas, and it must have specific specified characteristics. To effectively supply fuel to all these points, it is necessary to check its properties and set the required pressure.

A standard gas supply network consists of the following elements:

Gas pipelines with different pressure indicators;
Regulating and distribution stations and installations;
Control and monitoring equipment;
Dispatch and operational service.

On the classification of gas pipelines

The need to classify gas pipelines came into our lives with the widespread spread of technologies for using gas for the needs of the population. Heating of residential, administrative, and industrial buildings, the use of gas both in cooking and in production has long become an everyday thing for us.

Main gas pipeline

The classification of gas pipelines is the necessary measures and rules for systematizing the laying of gas pipelines. Gas communications can differ both in their purpose and in a number of indicators, such as: pressure, the material from which it is made, location, volumes of transported gas and others.

The path of natural gas from the field to consumers

The use of gas equipment for cooking and heating has long become the norm of life both in large cities and in remote villages. The widespread use of blue fuel has solved many consumer problems and made life much easier than it was just a few decades ago. There was no need to use firewood, coal and other materials for heating, and cooking on gas stoves made it possible to free up a lot of time for housewives. The industry also experienced a revolution due to the introduction of gas. Many enterprises have their own gas stations and boiler equipment, which allows them to increase production speed and reduce production costs.

Gas field Source gazprom.ru

We are all accustomed to lighting gas on the stove every day, turning on hot water heated by a boiler, and warming ourselves in winter from the warm pipes at the boiler. But few people really think about how exactly blue fuel gets into our homes. After all, gas fields are located in remote areas, sometimes at a distance of several thousand kilometers from the final point of consumption. In order to organize uninterrupted delivery of fuel to cities and villages, there is a wide network of branched channels, which are gas mains.

GDS station Source saratov-tr.gazprom.ru

Before entering the main network, gas travels a long way and is subjected to a multi-stage system of influences. Immediately after fuel is extracted from the field, it is thoroughly cleaned and prepared for transportation. At compressor stations, gas is injected so that it moves along the pipeline at high speed and also with high pressure. This is necessary so that the fuel quickly travels distances and after some time ends up at the gas distribution station, where it will be further processed.

Gas equipment company Source ngosar.ru

At the gas distribution station there is special equipment that lowers the gas pressure in the pipes and saturates it with special substances - odorants. This is done to prevent gas leakage, because in its pure form it is colorless and odorless. The fuel is then further purified before being sent to gas distribution pipelines in populated areas.

Gas control point Source gazstn.ru

Gas equipment is configured to consume gas at certain pressure levels that cannot be changed. Typically these are low or average values typical for internal home networks. To achieve such values, special installations are used at stations that reduce fuel pressure.

Shut-off gas valves Source pgo.by

Before entering internal gas pipelines, within populated areas, fuel is transported through external pipes and passes to gas distribution points in cities and villages. There the gas is once again purified, its composition, quality and pressure are regulated, its pressure is again reduced and sent further in the direction of each individual house, building, and enterprise.

Gas stove burners Source vestnikao.ru

Having gone through this entire difficult path, the gas finally gets inside our homes, where it is distributed to each type of equipment. Gas stoves, boiler systems, water heaters and other devices - they all work thanks to this type of fuel. All types of devices have special burners in which air is added to make the mixture flammable. Without access to oxygen, the gas will not burn, so this condition is necessary for the operation of the devices.

Multi-stage gas supply system

The need to create several stages in the local natural gas supply system, incl. caused by the presence of consumers requiring supplies of gaseous fuel at various pressures.

Gradation of gas pipelines by stages

Two-stage. Formed by networks under low and medium pressure, or low and high pressure;
Three-stage. Consist of communications with high, medium and low pressures;
Stepped. They are formed by gas pipelines with pressures of all levels.

Alternating high- and medium-pressure lines is required due to the significant length of network pipelines, as well as several transportation directions. In areas with significant population density, the installation of gas pipelines carrying gaseous fuel under high pressure is not recommended.

Another common reason is that in older areas, city streets are not wide enough to accommodate high-pressure gas supply lines. After all, the higher the pressure of the gas moving through the pipeline, the greater the distance required between communications and neighboring buildings.

The need for a stepped gas supply scheme is also caused by technological requirements for the connection and installation of gas control units installed on buildings.

Types of urban networks according to purpose

Urban areas are equipped with the most extensive network of gas supply communications.

The urban complex supplying natural gas includes the following types of gas pipelines:

distribution, conducting gas under different (actually necessary) pressure. Provide transportation throughout the serviced territory;
subscriber branches supplying gas from distribution mains to specific subscribers;
intra-house and intra-shop.

The gas distribution communications scheme designed for the city, supplying gas under medium and high pressure, forms a common network. Our proposed article will introduce you to the specifics of developing a project for gasification of a private home.

Those. Natural gas is supplied to utility consumers, boiler houses and industrial facilities via a common gas distribution network. The construction of separate backbone networks for municipal or industrial consumers is unprofitable from an economic point of view.

When choosing planning solutions for urban gas supply, the layout and size of the city, population and building density, and the needs of power plants and industrial facilities are taken into account. The prospects for the future development of the city and the presence of major obstacles (artificial, natural) to gas pipeline communications are taken into account.

Reasons for the fall

When residential properties are put into operation, the gas supply system is adjusted to optimal parameters, which should fully satisfy domestic needs. However, situations often arise when the pressure in the gas pipeline drops.

A drop in pressure, in addition to discomfort, significantly reduces the safety of using gas appliances. In particular, the burners of a kitchen stove may spontaneously go out, which is fraught with the subsequent leakage of an explosive substance.

What is the increase in consumption at low temperatures?

In winter, a drop in gas pressure is observed most often. This is due, first of all, to a sharp increase in its consumption due to the inclusion of various gas appliances (boilers, boilers, heating appliances, fireplaces, etc.) at full power.

Many residents warm up the room by turning on the burner on the stove. In addition, the throughput of the supply pipeline is also reduced. Condensation forms in the pipes, which freezes at sub-zero temperatures, which significantly reduces the internal diameter of the line.

Poor technical condition of the gas pipeline

The second most common reason is the unsatisfactory condition of the distribution station equipment and the pipes themselves. If preventive maintenance and repairs are not carried out periodically, this will certainly affect the pressure in the gas pipeline.

Often the culprit is pipe metal corrosion , especially if the pipeline was manufactured in violation of standards and low-quality, cheap materials were used.

Leakage: how does it happen?

A gas leak not only reduces its pressure, but is also a fire hazard. This phenomenon is most often observed at the junction of pipes, installation of shut-off equipment, bends, and connections of gas appliances. It can occur both indoors and outdoors (in basements, entrances, on highways).

The presence of a leak is indicated by a characteristic, pungent odor of gas. If it is detected, you must immediately notify the gas service.

Connecting new consumers

When designing gas networks, they are designed for a certain consumption with an established reserve for unforeseen cases. In practice, it is not uncommon for additional consumers to be connected that can significantly change the entire gas distribution picture.

Residents often make uncoordinated connections to various gas appliances of decent power. Most often, a 2-burner stove is replaced with a 4-burner unit, and even with a powerful oven. One apartment will have little effect on the system, but several such changes can reduce the pressure in the common gas pipeline.

The strongest impact is exerted by business activity on the ground floor of an apartment building. Catering establishments and other gas consumers must have an individual gas network that is not connected to the gas pipeline at home. However, there are cases of their insertion into an existing pipeline, which significantly affects the gas pressure.

Payment for housing and communal services is the responsibility of the homeowner. This rule also applies to gas supply. It is not uncommon for certain circumstances to result in arrears in payment. You can find out how to get information about the amount of debt, pay for gas supply using the Internet, and also learn about the procedure for turning off gas from our separate materials.

Standards for construction and installation work when creating a home gas network

The presence of a project for individual housing construction is not required, as it is stated in the Town Planning Code, and in PP No. 1314 it is stated that the GRO can only “check the gas consumption network installed by the applicant during the activities carried out by the contractor for connection before the actual start-up of gas.” That is, it is recommended to have a project, as in any construction, but not necessary; and even more so, its absence cannot be a reason for refusal of acceptance. As for the installation work itself, there is an updated version of SNiP 42-01-2002 - SP 62.13330.2011 with changes No. 1 and No. 2, “Gas distribution systems”.

In order not to copy a huge amount of information, there are a number of basic rules that must be strictly observed:

When laying pipes through ceilings or enclosing structures, a sleeve sealed with elastic material is used.
Pipe connections are not allowed at wiring points.
For the intra-house network, only welded pipe connections are used; threaded fixation and flange connections are permissible only for connecting shut-off valves, specialized devices and flexible metallized hoses (diameter 10 mm) for the transition to gas-consuming equipment.
All installed fittings must be accessible for maintenance.
Inside the house, gas pipelines are mounted along the walls without slope, the risers are strictly vertical.
The height from the floor to the gas pipes ranges from 220 mm for a flat ceiling and 200 mm for a sloped ceiling.
The distance from the pipe to the wall is not less than half its diameter, but not more than 100 mm.
Gas pipes should not cross any window or door openings or ventilation.
The minimum distance from the main line to the electrical panel is 0.3 meters.
There must be a minimum of 250 mm between the gas pipe and parallel electrical wiring if the cable is laid open, and at least 50 mm (from the edge of the pipe) if the wiring is hidden.
When the main line and cable intersect, the distance between them must be at least 100 mm; laying without a gap is acceptable if the cable is covered with a wide rubber or ebonite sheath.
If a gas pipeline crosses water, sewer or other pipes, the clear distance between them is at least 20 mm.
For internal installation, the distance from the gas meter to the boiler or stove is at least 80 cm.
Gas water heating equipment cannot be installed directly in the bathroom.
The pipeline is attached either to detachable clamps (if the pipe diameter is up to 40 mm), or tightly to brackets or hangers (if the pipe diameter is more than 40 mm).

The fewer seams and connections there are, the more reliable the system; it is advisable to immediately select pipes of sufficient length. Even without a project, it is not so difficult to sketch out a wiring diagram in a program or graphically and calculate the required segments.

Requirements for pipe selection

Pipelines made of HDPE, steel, copper and polypropylene are used to transport gas. The technical conditions for their production are specified in the relevant GOSTs. The most used materials for domestic gas pipelines are water and gas pipes. Designed for internal and external networks with compression up to 1.6 MPa, nominal bore 8 mm. It is possible to use metal-plastic products made of polyethylene brand PE-RT.

Underground gas pipelines may be made of polyethylene materials with a frame made of metal mesh and synthetic fibers, metal-plastic products.

For high and medium pressure pipelines, seamless or electric-welded steel pipes of large diameters are used.

The material of pipes and connecting parts is selected taking into account gas pressure, outside air temperature at the installation sites, the presence of groundwater and vibrations.

Modification of the slab for bottled gas

Not every stove can initially run on liquefied gas. The main obstacle is the higher operating pressure, due to which there is a lack of oxygen in the burners, which is expressed in the yellow color of combustion and the appearance of soot.

The situation can be corrected by replacing the methane nozzles with nozzles for LPG. They have exactly the same form factor, but the hole diameter is slightly smaller. If you plan to connect a new stove, it will most likely come with a set of liquefied gas nozzles. If there are no replacement jets, they can be purchased at a reasonable price.

The diameter of the holes in the liquefied gas nozzles depends on the pressure in the outgoing chamber of the reducer and the power of the burner. Thus, the standard values for liquefied gas stoves are considered to be diameters of 0.43–0.6 mm for a pressure of 50 mBar and 0.5–0.75 for a pressure of 30 mBar. Individual cooker manufacturers may set their own diameters, and the use of nozzles with different hole diameters may void the warranty.

Replacing jets can be done in two ways, depending on the design of the plate. In the simplest version, it is enough to remove the burner body and look inside the seat sleeve. If a nozzle is visible at the bottom - a hexagonal head with a hole in the center - unscrew it with a 7 or 8 mm socket wrench and screw in the nozzle to replace it. If a cone with a hole is visible inside, you will have to remove the top panel by unscrewing several bolts on the sides from different sides. The nozzle itself in this design option cannot be unscrewed; it is pressed onto the stuffing box seals. You need to unclench the whiskers of the crimp coupling, move the nozzle down along with the supply tube, and then pull the nozzle out of the fitting and install a new one.

Types of pressure gauges

Flow meters are also distinguished by other characteristics. Meters are needed in different areas, where very different quantities are determined. The measurement accuracy will also vary.

By accuracy class

This is understood as the permissible deviation of the measurement error from the measurement on the instrument scale. The indicator is indicated on the dial. When purchasing a device, you need to pay attention to this.

Pressure gauges with accuracy classes are supplied to the Russian market: 4, 2.5, 1.5, 1, 0.6, 0.4, 0.25, 0.15. Foreign countries also have a variant with a class of 1.6.

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The indicator allows you to quickly determine whether the device is faulty or does not comply with the measurement class. If a pressure gauge with a maximum value of 10 kgf/cm² is used, with an accuracy class of 1.5, this means that the permissible error is 1.5 from the scale, otherwise - 0.15 kgf/cm². If, when using the device, it turns out that the error is greater, the device needs to be changed.

By purpose

The classification is as follows.

General technical – pressure gauges for determining excess and vacuum pressure in any gaseous medium that is non-aggressive to the material of the device. They are used to estimate gas consumption in a network with low-compressibility gas and to determine the consumption of liquefied propane in a cylinder.
Special - designed for measurement in a specific part of the aggressive gas environment.
Reference - designed for testing and calibrating other pressure gauges.

General technical

Special

Reference

Pressure gauges for gas cylinders used in private homes must be checked at least once a year. This procedure is performed using a reference pressure gauge.

Introduction

This standard was developed to ensure the provisions of the Technical Regulations [1] for the design, reconstruction, construction and operation (including conservation and liquidation) of gas distribution and gas consumption networks of category 1a.

This standard has been adopted for the purposes of:

— establishing standards for the design, reconstruction, construction and provision of conditions for the safe operation of gas distribution and gas consumption networks of category 1a;

— protection of life and/or health of citizens, property of individuals and legal entities, state and municipal property;

— protection of the environment, life and/or health of animals and plants;

— ensuring energy efficiency.