Only specialists in this field have the right to carry out gas pipeline installation work. To provide gas to a private home or to repair gas communications, you need to choose professionals.

Pipe installation is carried out in accordance with SNiP 2.04.08–87 standards. This document regulates all actions, distances and dimensions of installed communications.

The gas pipeline is one of the most important parts of the house. Thanks to it, heating appears in the room; using gas appliances, you can cook food and heat water for hot water. But if used incorrectly, gas can become a serious problem leading to tragedy. To avoid this, standards were invented that were used when installing a gas pipeline. They ensure the safety and correct operation of devices.

Basic Rules:

• The intersection of the gas main and window openings, doors and ventilation is not allowed.
• Distance from pipe to electrical panel should be at least half a meter.
• Between gas system and electrical communications should be at least 25 cm.
• The gas pipeline must be located at a height of 220 mm from the floor, in rooms with sloping ceiling this distance is 200 mm.
• A flexible hose with a diameter of 10 mm can be connected to gas equipment.
• Water heaters cannot be installed in the bathroom.
• High humidity creates reverse thrust, due to which the room is filled carbon monoxide and can cause poisoning.
• The distance between the stove and the pipe must be maintained; it must exceed 80 cm.
• After the metering devices, the pipe slope should begin at 3%.
• The metering device should be located at a height of 1600 mm from the floor.
• The meter should be located at a distance of 80 cm from heating equipment or slabs.
• To install a gas pipeline in the wall, it is necessary to make a hole in the wall separate from the ventilation.
• Access to communications must be ensured. You can place them in a box, but it must be equipped with a lid for access.

Preparatory work

Before installation begins, it is necessary to prepare the site. To do this, you will have to coordinate the work with the relevant organization. Coordination of gas pipeline installation is carried out in the following order:

• Write a statement to the company that monitors the gas industry.
• The specialist will make a verdict on the possibility of carrying out certain works.
• If the work is permitted, the specialist will draw up an estimate for its implementation.

Permits for gas pipeline installation are issued in accordance with SNiP 2.04.08–87 and “Safety Rules in the Gas Industry.” Preparation, coordination and drafting of the project make up a significant part of the costs.

Installation equipment and tools used

To install the gas pipeline, craftsmen use special equipment:

• Long-fiber flax or FUM tape for making threaded connections.
• Lever wrenches with parallel jaws. They should be equipped with notches for better adhesion to the part.
• Apparatus for welding.
• Fittings are parts with fine threads for connecting several elements.

All tools and system elements must have a certificate from the factory that manufactures these parts. All certificates must comply with the requirements of Gosgortekhnadzor. If there are no certificates, then the use of such pipes is impossible.

Procedure

Installation of a gas pipeline begins with measurements of all required sizes. Based on the data obtained, specialists draw up a project for the future gas network.

After approval, it is necessary to order the production of the parts required for the project, buy Consumables and deliver it all to the assembly site.

When all parts of the structure are ready and delivered to construction site, you can start working directly. When laying pipes, it will be impossible to use gas equipment, so you have to worry in advance alternative method heating or cooking at the time of work.

Gas pipeline installation technique

Work begins with introducing the pipe into the building. For this purpose in external wall The case is placed and insertion is made through it. A riser is already installed inside, located 20 mm from the walls in a vertical position. Connections at this stage are made using a welding machine.

The cases must be located at all points where the pipe intersects with interfloor ceilings, walls and staircases.

Gas pipeline fasteners must be installed at a distance of at least 2 m from each other. These rules apply to pipes with a diameter of 25 mm. They must allow repairs and diagnostics of possible damage during operation. The end of each fastener is driven into a special wooden cork located in the wall. After this, the attachment point is filled cement mortar to give extra strength.

There are a number of rules for performing welding work:

Rules for performing welding work

• Welding can be performed on pipes with a diameter not exceeding 150 mm and with a wall thickness of up to 5 mm.
• Arc welding is used when the pipe thickness exceeds 150 mm or the wall thickness exceeds 5 mm.
• Before installation, it is necessary to prepare the pipes for welding. To do this, they are cleaned of contaminants.
• Each welded joint must be easily accessible. It is not allowed to hide seams in the wall or case.

It is important to note that free access is required for all connections, not just welds.

All connections are made by welding. Threaded connections are allowed only in places where shut-off valves, metering devices (gas meters) are installed, and where a pipe is connected to a hose leading directly to gas equipment.

Question #6: Hello. Exist standard series or included with the mount vertical gas pipeline to a ventilated façade? Thanks in advance. (Valentina Yurievna Answer: Today on construction markets you can purchase hardware and fasteners for every taste, both domestic and foreign manufacturers. One of these products is a collapsible fastening clamp (see photo). Designed specifically for fastening gas, sewerage, heating and water supply pipes to load-bearing structures on walls.

It consists of two metal brackets, one of which has an M8 nut welded to it, rubber gaskets are installed in the brackets, and two screws are used to tighten the clamp. To attach the clamp to the wall, use either a stud with a dowel or an anchor bolt.

Fastening to the wall through already installed siding is carried out as follows: directly through the siding and insulation, drill a hole in the wall for a dowel or anchor bolt, screw the pin into the dowel or bolt with the body into the prepared hole, and screw half of a collapsible clamp onto the other end of the pin or bolt. That's it, the mount is ready for use.

Such collapsible clamps today are indispensable when carrying out repairs and arrangement of heating systems, water supply and gas supply, and of course sewerage. The clamps are of high quality and meet the highest requirements; they are made from high quality steel cold stamping method, galvanized coating, wide range of sizes: 1/2", 3/4", 1", 1 1/4", 1 1/2", 2", 2 1/2", 3", 3 1/2", 4", 5", 6".

All sets of dismountable clamps are equipped with rubber gaskets that protect the metal of the clamps from corrosion upon contact with the working pipe, and also act as sound and vibration dampers.

The nut is welded to each clamp using contact welding, this ensures high reliability of the welded unit during fastening and installation of pipes. This connection can withstand a rated load of 150 kg, and the pull-off force is guaranteed to be 450 kg.

I think depending on the material load-bearing walls you choose the type of fastening yourself: either a stud with a dowel or an anchor bolt. If the walls are made of gas blocks, then you can use chemical anchors. A hole is also drilled through the siding and insulation, a special mixture is pumped into the hole and then an anchor bolt is inserted, passing through the hole. chemical reaction, polymerization of the substance occurs and the anchor bolt is firmly fixed in the wall of the house. And then according to the diagram above: we attach the collapsible clamp with rubber gasket. Good luck.

Correct fastening To building structures pipelines ensures their operational reliability. If existing installation standards are violated, the pipeline may be damaged and its durability reduced. In this case, the specifics of the materials from which the pipes are made should be taken into account. In particular, the possibility of their expansion with temperature changes environment. Exactly physical properties materials determine the list technical requirements requirements for fastening elements.

Basic and special properties of fasteners

Vertical and horizontal pipelines are attached to building structures using fastening elements - hangers and supports. The installation process involves brackets, strips, clamps, consoles and embedded parts for fastening pipelines.
Fasteners must meet the following basic requirements:

• keep high quality and reliability even during repeated intended use;
• ensure its functionality different conditions pipeline installation, including under increased loads;
• be unified and universal;
• must have high mechanical and corrosion resistance, capable of withstanding aggressive environmental influences.

In addition, the installation of support structures for securing pipelines should not cause difficulties. It is necessary to make working with pendants and supports easy and simple. Fulfilling this requirement ensures excellent ergonomics of work processes.

Special requirements are imposed on load-bearing structures when it is necessary to take into account the specifics of the material from which the pipes are made. When securing polymer pipelines, these special requirements must be taken into account.

• In straight sections, polymer structures can change their length due to the high coefficient of linear expansion of this material. In this case, the supporting structures should not interfere with the free movement of the pipeline. This means that compensators that have special design fixing clamps.
• Unlike metal, polymers are particularly sensitive to mechanical damage. Therefore, parts that come into contact with such material must be smooth, free of sharp edges and burrs. A metal clamp with a screw is more often used in relation to steel structures, and in the case of polymers, flat clamps with a smooth surface are used inner surface, rounded edges and with spacers. Plastic clamps for fastening Fusiotherm pipelines are popular.
• The strength, heat resistance and hardness of polymers, when considered in comparison with steel, is low. Therefore, pipelines made from them cannot be used as bearing structures.
  Polymer pipes not secured in clamps on fixed supports. This leads to their damage.

Elements for fastening hydraulic pipelines are produced in two design options. Without a solid base, if the ambient temperature air environment or the liquid being moved does not exceed 30°C, and with the base at more high temperatures.

Calculation of fastenings for pipelines

If the design does not require a solid base, then the gaps between the fastening elements are established by calculation. At the same time, the design of the fastenings itself must withstand not only the weight of the pipeline, but also the liquid that will be transported through it. This means that it must be strong enough and reliable.

In the absence of unified technical documentation, one should be guided by design standards that were developed by a number of organizations specializing in this area. They are presented to users in the form of albums of drawings and OSTs. Fastenings are calculated based on:

• OST 36-17-85;
• SN 527-80;
• OST 95-761-79 and others.

In these documents, the distance between hangers and supports is indicated depending on the diameter of the pipelines, pressure, temperature of the transported liquid and the external environment. SN 527-80 also takes into account the recommended distance to the surface of galleries, tunnels, channels and walls when attaching a pipeline to a wall. If the density of the transported liquid is high, it is necessary to use correction factors.

Types of fastening structures

Load-bearing fastening structures are divided into the following types:

• Fixed supports. When using this fastener, angular or linear movement of the fixed areas is not allowed.
• Guide supports. The use of this design allows displacement in only one direction. As a rule, only along the horizontal axis.
• Hard pendants. Movements are permissible, but only in horizontal plane.
• Spring suspensions and supports. Movements are possible both in the vertical and horizontal planes.

Types of fastening pipelines to the wall

Requirements for supports and suspensions

If fixation occurs between two fixed supports, the movements that may occur as a result of the change temperature conditions, installation tension or displacement of supports must be self-compensating. But such compensating ability, as calculations show, is sometimes not enough. In this case, special compensators must be installed.

The pipe clamp is equipped with a screw/bolt

They are made from pipes of the same type and diameter as the structure as a whole. Most often they are made in the form of the letters “P” or “G”.

If the structure is fixedly fixed, the fastenings must withstand the weight of the pipeline itself, the liquid that moves along it, as well as axial loads generated by thermal deformation, vibrations and hydraulic shocks. When installing polymer products, movable supports are most often used.

If the installation is carried out in fixed supports, restrictive rings or segments 10-20 mm wide, which are made from pieces of pipes of the same plastic, are welded to the pipes. These segments or rings should be located on both sides of the support.

Selection of fastening elements

Suitable fastenings are selected taking into account many factors. The choice depends on the location of the installation site and the purpose specific system and so on.

Fastening plastic pipe

Sometimes the pipe must be insulated from the source of cold or heat. If you use a simple clamp that fixes the area, then it will not provide the gap from the adjacent surface necessary to solve the problem. But, for example, a ring support, which has a threaded extension and a plate for fastening to the supporting surface, will completely eliminate the problem.

If you have to secure heavy cast iron pipes, then use special fasteners that can withstand heavy loads. For vertically located systems it is installed on the floors. Horizontally oriented systems are fixed not even one at a time, but in groups of pipes laid on a console.

A competent approach to the selection and placement of fasteners allows you to operate the pipeline for a long time and efficiently without fear of emergency situations. But we should not forget about the economic component of this problem. After all, exceeding the required and sufficient number of elements can lead to an unjustified increase in the cost of the design and complexity installation work.

Video: calculation of pipeline fastenings

Chapter 11. PIPELINE INSTALLATION TECHNOLOGY

Installation of pipelines should be carried out in accordance with the project, detail drawings (CDD), work execution plan (WPR) and safety regulations. Pipeline installation is carried out mainly with ready-made units manufactured in pipe procurement shops complete with fittings, as well as pipeline blocks assembled on site, with maximum mechanization of installation work. Installation of pipelines “in situ” from individual pipes and parts is allowed only in exceptional cases.

§ 1. PREPARATORY WORK

Before starting work on pipeline installation, the foreman of fitters studies working drawings, specifications, PPR and other technical documentation for the facility being prepared for installation. Having received an installation task, workers must familiarize themselves in detail with the technical documentation and safety regulations. At the same time, they study the pipeline laying diagram, plans and dimensions of the building, drawings of piping of apparatus and equipment, fastening of pipelines and supporting structures, specifications for products and fittings.

Before installation of pipelines begins, the following preparatory work must be completed:

Compliance with the design for the installation of support structures for pipelines, installation of embedded parts for fastening pipelines, the presence of holes for pipelines in building structures, fastening of fixed supports of free-standing support structures and overpasses were checked. Installation and sealing of embedded structures and holes for pipelines are provided for in the construction part of the project and must be carried out by the construction organization.

accepted under the act of construction organizations buildings, building structures, overpasses, trays, trenches with checking their construction readiness for installation of pipelines and compliance with the design marks to which the pipelines are attached in the installation drawings. When accepting trenches, the compliance of their dimensions and elevations with the design ones, the correctness of the slopes, compliance with the slopes, the quality of the bed and the condition of the fastenings must be checked. The bases of trenches in rocky soils must be leveled with a layer of sand or gravel at least 20 cm thick;

Compliance with the drawings of the types, sizes and locations of fittings of the equipment to which the pipelines are connected, and the accuracy of its installation in the axes and marks were checked. All deviations from the project must be recorded in the work log;

Sites for intermediate storage and consolidation of pipeline units have been organized. Intermediate storage of pipes, parts and assemblies is carried out in open areas along each line separately and they are located so that free passage and access to them is ensured for inspection, checking markings and performing loading and unloading operations. When stored in an open area or in rooms without a wooden floor, all assembly blanks, regardless of the nature of their installation, are laid on wooden pads with a height of at least 200 mm so that it is possible to strap them when submitting for installation. It is recommended to deliver finished pipeline assemblies to sites in containers, which creates convenience during storage, on-site movement and loading and unloading operations. It is recommended to place signs near the storage areas of workpieces indicating the unit number and line number for the project;

prepared workplaces, tools, installation devices; equipment for welding stations; the necessary scaffolding recommended by the PPR has been installed;

units, sections, pipes, fittings, compensators, stops, hangers and other products are accepted for installation; their completeness, compliance with the project requirements and delivery conditions were checked. Industrial installation methods predetermine that components, supporting structures, supports and hangers are delivered to the installation site from pipe procurement shops with the maximum degree of factory readiness and completeness. The completeness of the delivery is checked according to specifications, packing lists and other shipping documents, and the condition is checked by external inspection. When loading, it is not allowed to reset pipe blanks and store them in bulk.

Before the installation of pipelines for sanitary systems begins, it is necessary to check the completion of general construction work in buildings and structures, including accepting holes and grooves for installation for laying pipelines in compliance with the dimensions given in the table. 61.

When constructing external water supply, sewerage, gas pipelines and others, before digging trenches and pits, all underground communications must be opened. Communications are opened using shovels, without using percussion instruments. The autopsy areas are fenced off and these areas are illuminated at night. Existing communications that cross the pipeline being laid or are located parallel to it at a distance that is unacceptable according to the standards are shifted in accordance with the project. Before proceeding with the installation of external pipelines, the route passing

Table 61. Dimensions of holes and grooves for laying pipelines of sanitary-technical systems, mm

Heating

Riser	yuohyuo
Two risers	150ХУ0
Connections to devices	yuohyuo
Main riser	200ХУ0
Highways
Plumbing and	sewerage
One water riser	yuohyuo
Two water risers
One sewer riser
D H57 mm	150ХУ0
The same, ?>„ 108 mm
Two water risers and
one sewer riser
D K57 mm
Same, 108 mm

through a populated area, the entire length must be fenced on both sides inventory shields with the installation of warning signs. In areas of heavy traffic and pedestrian traffic, red flags should be installed on the fence.

The laying of pipelines must be preceded by a breakdown of their routes, which is carried out in accordance with the project, where the connections of the pipeline axes to the floors, walls and columns must be indicated. The axes and marks of the pipelines are transferred to the installation site and the installation locations of supports, fasteners, compensators and fittings are marked.

When laying out the route of intra-shop pipelines, the axes and marks are fixed with the help of signs applied directly to the walls of the building, metal and reinforced concrete structures with a scriber or oil paint. The breakdown of straight horizontal axes is carried out first of all; this is done using a steel string with a thickness of 0.2-0.5 mm or a nylon thread, along which the axes of the pipelines are marked on the structures, indicating vertical marks (taking into account the required slope of the pipeline). The heights of the horizontal axes of pipelines are found by measuring from the level of the finished floor with a plumb line and a steel tape measure. If it is impossible to measure from the floor or ceiling, marks from existing benchmarks (elevation marks established by construction organizations) are transferred to the pillars and columns of buildings along the route of the future pipeline every 10 m using a level. From the transferred mark, measure the distance to the pipeline axis, which is determined by subtracting the benchmark mark from the design distance to the pipe axis. A square is applied to the pipeline axis mark transferred on the column and a horizontal line is drawn with bright paint. The resulting mark is transferred to the next column. If the pipeline will be laid with a slope, then the mark is transferred to the next column, taking into account the direction and slope indicated in the project. Typically, all process pipelines are laid with a slope towards their possible complete emptying of residual liquid by gravity.

The minimum slope values ​​for process pipelines for various purposes, m, per 1 m length are as follows:

Gas pipelines and pipelines (in the direction

First, the route of the main line is broken down, and then the axes of the branches to devices, machines, fittings or to other lines. Along these axes, the installation locations of compensators, fittings, movable and fixed supports, pendants, and brackets are marked.

When laying non-insulated pipelines in channels, on high and low supports and overpasses, the distance between the walls of the pipes in the clear is taken taking into account the location of the flanges staggered, mm not less: for pipes with?>„, respectively 57...108-80; 108...377-100; more than 377-150.

The laying of pipelines inside buildings and installations is carried out on supports along walls and columns, on suspensions to floor beams and ceilings, taking into account the free movement of lifting and transport equipment. The distance from the floor to the bottom of the pipes or the surface of their thermal insulation must be at least 2.2 m.

The distance between the outermost pipeline or the surface of its thermal insulation and the wall must provide the possibility of free thermal expansion, inspection and repair of the pipeline and fittings and is taken in the light to be at least 100 mm. Pipelines laid along the walls of buildings should not cross window and door openings. When laid along the external walls of buildings, pipelines are located at least 0.5 m above or below window openings.

Upon completion of work on laying out the pipeline route, a report is drawn up, to which a list of axes and turns is attached.

§ 3. INSTALLATION OF SUPPORTS AND SUSPENSIONS

Supports and hangers are used to fasten horizontal and vertical pipeline lines to buildings, structures and technological equipment. Based on their purpose and design, supports are divided into fixed and movable.

Fixed supports rigidly hold the pipe and prevent it from moving relative to the supports and supporting structures. Such supports absorb vertical loads from the mass of pipelines with the product and horizontal loads from temperature deformation of pipelines, water hammer, vibration, etc. Depending on the method of attachment to the pipe, fixed supports are welded and clamped. In clamp supports, special stops are welded to the pipe to prevent the pipe from slipping in the support. Fixed supports are manufactured according to the standards of design organizations and manufacturing plants.

Movable supports support the pipeline, but do not prevent it from moving due to temperature deformations. They only support vertical loads from the mass of the pipeline with the product. They are divided into sliding, roller, frameless and others. Movable supports are manufactured in accordance with GOST 14911-82* and GOST 14097-77, OST 36-11-75, as well as according to the standards of design organizations and manufacturing plants.

The pendants are attached to supporting structures and building floors using rods with bolts or welded eyes. The length of the rods is set by design and adjusted with nuts or couplings. Pendants are manufactured in accordance with GOST 16127-78, OST 36-12-75.

Installation of supporting structures, supports and hangers is carried out after the pipeline route has been laid out, when the axes have been marked and the mounting locations for fittings and compensators have been determined. Support structures are most often attached to reinforced concrete elements of buildings - columns, crossbars, panels, welding them to embedded parts.

After securing the supporting structures, supports and hangers are usually installed in the design position along with the pipeline assemblies and blocks. If it is necessary to pre-fix the installed pipelines on temporary supports and hangers (in the case of installation of pipelines of a complex configuration in cramped conditions, etc.), the latter must correspond in strength to the weight of the pipeline fixed to them and be installed on durable structures. After installation of all pipeline components and welding of installation joints, permanent supports and hangers must be placed, and temporary ones must be removed.

When installing supports and support structures under pipelines in accordance with SNiP 3.05.05-84, the deviation of their position from the design plan should not exceed ±5 mm for pipelines laid indoors and ±10 mm for external pipelines, and the slope should not exceed +0.001 , unless other tolerances are specifically provided for by the project. To level the elevations and ensure the design slope of the pipelines, it is allowed to install steel spacers under the soles of the supports and weld them to the embedded parts or supporting structures.

The length of the suspension rods is changed due to the threads on them.

Welded joints of pipelines must be at a distance of no less than 50 mm from the supports, and in steam and hot water pipelines controlled by the USSR State Technical Supervision Authority - no less than 200 mm. It is recommended that flange connections of pipelines be located, whenever possible, directly at the supports.

Fixed supports are welded to the supporting structures and securely fixed to the pipe using clamps with locknuts installed on the bolts. The support pad and clamp are pressed tightly against the pipe. To prevent the pipe from moving in a fixed support, thrust plates are welded to the pipe, which should rest against the ends of the clamps. The stops are installed so that the gap between the clamp is no more than 1.5 mm. The surface of the stops and the surface of the pipe at the installation sites must be cleaned with a hand grinder before welding. Thin aluminum spacers are installed between the alloy steel pipe and the carbon steel support or clamp to protect the contact points from electrochemical corrosion.

Movable supports and their parts should be installed taking into account the thermal change in the length of each section of the pipeline, for which purpose the supports and their parts must be shifted from the axis of the supporting surface in the direction opposite to the pipeline extension. The displacement value is usually taken according to the design to be equal from the base to the full thermal elongation of a given section of the pipeline. The suspension rods of pipelines with thermal elongation must be installed with an inclination to the side. The amount of displacement and the direction of preliminary tilt of the rods are indicated in the project.

§ 4. INSTALLATION OF PIPELINES

With industrial methods of work, installation of tr^. pipelines are carried out in units, sections and blocks. Nowadays, installation with aggregated blocks has become widespread, i.e., pipeline blocks are assembled together with technological equipment and install them on a common frame.

The enlarged assembly of the blocks is carried out on stands and racks located in the operating area of ​​the assembly cranes. Here it is advisable to use stands 21338 (see Fig. 10) and centralizers (Fig. 46). Before assembling the blocks, temporary plugs are removed from the fittings and assemblies and the flanges and pipe ends are unpreserved. After control measurements of finished units and checking the location of fittings on the equipment, the assembly of blocks begins. The dimensions and weight of the blocks should ensure ease of transportation to the installation site and installation in the design position. Knots and blocks must remain strong when lifted, otherwise they may become deformed. If necessary, temporary structures must be installed to provide the required rigidity.

Rice. 46. ​​Pipe welding centralizer TsT-426:

1 - screw;2 - screw; 3 - cheek;4 - link; 5 - roller;6 - straightening

vnnty

Straight sections are laid after installation and fastening of adjacent units and blocks. It is advisable to attach supports and hangers to the units and blocks being lifted; this facilitates subsequent alignment. When installed in the design position, units and blocks, as well as sections and individual pipes must be laid on at least two supports and securely fastened. Temporary fastening of pipelines during the installation period is permitted in exceptional cases. Pipelines laid through walls, ceilings or other elements of buildings must be enclosed in sleeves in accordance with the design instructions. In the absence of instructions, it is recommended to use pipe sections with an internal diameter 10-20 mm larger than the outer diameter of the pipeline section enclosed as sleeves. The ducts should protrude 50-100 mm on both sides of the building element crossed by the pipeline. Sections of pipelines in sleeves should not have joints. The gap between the pipeline and the sleeve is filled on both sides with asbestos or other non-combustible materials that allow the pipeline to move in the sleeve.

Lifting and installation of units and blocks into the design position is carried out using cranes, rigging equipment and devices provided for by the PPR. Hoists, blocks and other rigging equipment used in the installation of pipelines are allowed to be attached to components of building structures that have the necessary safety margin. If there are no relevant instructions in the PPR, the possibility of fastening to building structures must be agreed upon with the design organization.

Pipeline fittings are usually installed complete with units or blocks. When installing fittings that are not included in units or blocks, it is first secured to supports, after which a pipeline is connected to it.

It is advisable to install external above-ground pipelines in enlarged blocks and sections. The dimensions and designs of blocks or sections are determined in the PPR and depend on the designs of overpasses, the number and location of pipelines on overpasses, their diameters, the availability of lifting mechanisms at the installation organization, as well as installation conditions. The enlarged assembly of blocks and sections is carried out on stationary or mobile lines. Sections are lifted onto supports or trestles usually using two cranes, the types of which must be specified in the PPR.

Installation of underground pipelines is carried out in the following sequence: trenches are developed; clean the bottom and walls of the trenches; dig pits in places of welding and insulation of joints; arrange the foundation for the pipeline; make the bottoms of wells and chambers; lower the pipes into the trenches, laying them on the base; closing joints are assembled and welded; install connecting parts and fittings, tamp and sprinkle the pipeline with soil (except for joints); blow the pipeline with air; preliminary test the pipeline for strength; isolate joints; filling up the pipeline. The final testing of the pipeline is carried out after completion of construction and installation work.

To center the ends of pipes assembled for welding and eliminate discrepancies between the edges along the perimeter of the pipes, centralizers are used. The pipe welding centralizer TsT-426 is a ball-and-link plate chain assembled from links mounted on freely rotating rollers with threaded holes into which retaining screws are screwed. The right extreme link is made in the form of two plate hooks that close the centralizer on the axles of a nut having a right-hand thread. To tighten the centralizer in joined pipes, use a screw located parallel to the tangent to the circumference of the pipe. The screw has right and left thrust threads. It is recommended to rotate the screw using a ratchet wrench with adjustable torque with a replaceable head with a 14 mm opening.

To center the pipes during their assembly, it is necessary to lay the centralizer so that both rows of plates are located symmetrically to the joint of the pipes, then the hooks are put on the trunnions of the right nut and by rotating the screw, the centralizer is pulled until the axes of the pipes being joined are aligned. Where it is necessary to eliminate the displacement of the edges, the retainer screws are screwed into the threaded holes of the rollers. In this case, the torque should not exceed 30 Nm.

When changing the diameter of the assembled pipes, the number of centralizer links is changed.

Technical characteristics of centralizer TsT-426

Outer diameter of joined pipes,

mm.........219-426

Maximum tightening torque, Nm:

Manufacturer......Poltava experienced

foundry-mechanical plant Minmontazh- special construction of the Ukrainian SSR

It is recommended to install pipelines laid in trenches in sections and strands up to 1000 m long. In this case, ready-made coded pipes or sections 24-36 mm long are laid out at the edge of the trench, assembled and their joints are welded in a fixed position. The lashes are assembled on plank beams or on excavated soil for the convenience of their subsequent slinging when laying in a trench. A distance of up to 35 m should be provided between the sunbeds, and the bottom of the trench should be planned taking into account the design slope. In order not to damage the insulation, the pipeline is lifted using special slinging devices - towels consisting of a steel rope and an internal protective sheath made of rubberized fabric. It is recommended to lay the string in a trench using three cranes located along the string at a distance of 15-40 m from each other, depending on the diameter of the pipelines.

Overhead gas pipelines should be laid on free-standing supports, shelves and columns made of non-combustible materials or along the walls of buildings. In this case, the following installations are permitted:

On free-standing supports, columns, trestles and shelves - gas pipelines of all pressures;

Along the walls of industrial buildings with premises related to fire danger to categories G and D – gas pipelines with pressure up to 0.6 MPa;

On the walls of public and residential buildings of at least 3 degrees of fire resistance - gas pipelines with a pressure of up to 0.3 MPa;

Along the walls public buildings and residential buildings of 4-5 degrees of fire resistance - gas pipelines low pressure With nominal diameter pipes, no more than 50 mm. The height of gas pipelines along the walls of residential and public buildings should be taken in agreement with the operating organization.

It is prohibited to lay transit gas pipelines:

Along the walls of buildings of children's institutions, hospitals, sanatoriums, cultural, entertainment, leisure and religious institutions - gas pipelines of all pressures;

Along the walls of residential buildings - gas pipelines of medium and high pressure.

The connection of underground steel gas pipeline inlets with the riser of the above-ground (basement) inlet must be welded using bent or steeply curved bends. Welded butt joints in sections of underground gas pipelines must be checked non-destructive methods control.

High-pressure gas pipelines up to 0.6 MPa are allowed to be laid along the walls, above the windows and doorways of single-story and above the windows of the upper floors of industrial buildings with premises classified as fire hazard categories G and D, as well as buildings of free-standing boiler houses.

It is not allowed to provide detachable connections and shut-off valves on gas pipelines under balconies and under window openings residential and public buildings.

In a free area outside the passage of vehicles and the passage of people, it is allowed to lay gas pipelines on low supports at a height of at least 0.5 m, provided that one or more pipes are laid on a support. Gas pipelines at exits from the ground should be enclosed in cases, aboveground part which should be at least 0.5 m. The end of the above-ground parts of the casings must be sealed with bitumen to prevent precipitation from entering the interpipe space.

Distance to buildings and structures, see table

In places where people pass, the height of the gas pipeline on supports is 2.2 m.

When laying a gas pipeline on supports closer than 2 m to the edge of the roadway, it is necessary to provide a protective fence. The minimum distance of the protective gas pipeline to buildings must be at least 2 m. Gas pipelines are secured to the supports using clamps.

Allowable spans between supports:

Pipe d- 20mm - 3 m

25mm – 3.5m

The gas pipeline is laid along the walls using brackets according to series 5.905-8 (Attaching a gas pipeline to the walls of a building). The distance between gas pipelines and walls should provide easy access for inspection and repair.

To combat corrosion, metal structures and pipes are painted twice with preliminary application of a primer.

Insulating flanges. Purpose and place of installation.

Insulating flange connection (IFS). Protection of gas pipelines with the help of IFS and inserts consists in the fact that the gas pipeline is divided into separate sections, due to which the conductivity of the pipe is reduced, and at the same time the strength of the current flowing through the gas pipeline is reduced and the solution to the issue of their protection is simplified.

The installation of EIF at the inputs makes it impossible to make electrical contact between the house and the gas pipeline. Installation of EIF on gas pipelines - entries into the house no higher than 2.2 m (usually 1.6-1.8 m from the ground surface for ease of maintenance).

When installing valves and compensators, flange connections must be bridged with permanent jumpers.

Placement of shut-off devices on the gas pipeline.

Shut-off devices on gas pipelines should be provided:

At the inputs there are residential, public, industrial buildings, in front of external gas consuming installations (mobile boiler houses, bitumen digesters, ovens for drying sand and firing building materials, etc.)

At the inlets to the hydraulic fracturing unit, at the outlets from the hydraulic fracturing unit with looped gas pipelines in systems with two or more hydraulic fracturing units;

On branches of inter-settlement gas pipelines to settlements or businesses;

On branches from gas distribution pipelines to individual microdistricts, blocks and individual groups of residential buildings;

For sectioning distribution gas pipelines of medium and high pressure to enable emergency and repair work;

When gas pipelines cross water barriers, as well as one line when the width of the water barrier at a low-water horizon is 75 m or more;

When crossing gas pipelines railways general network and highways Category 1 and 2 disconnecting devices should be placed:

In front of the territories of industrial, public utility or other enterprises.

Shut-off devices on external gas pipelines should be placed in wells, ground fireproof cabinets or fences, as well as on the walls of buildings. No-well allowed underground installation disconnecting devices connected by welding, designed for well-free installation and requiring no maintenance.

Switching devices intended for installation on the walls of buildings should be placed at distances from doorways and opening window openings not less than, m:

For low pressure gas pipelines – 0.5 m;

For medium pressure gas pipelines horizontally – 1.0 m;

For high pressure gas pipelines up to 0.6 MPa horizontally -3.0 m.

Distances from disconnecting devices on the gas pipeline located on the walls of buildings to receiving devices supply ventilation must be at least 5 m horizontally. When disconnecting devices are located at a height of more than 2.2 m

platforms made of non-combustible materials with stairs should be provided.

Purpose, device of shut-off and control valves?

Industrial pipeline fittings are:

1. shut-off

2. regulating

3. safety

4. control

Shut-off valves designed to turn on and off individual sections of pipelines during operation. This includes taps, valves, and gate valves.

Control valves are designed to change the pressure or temperature, or flow of the transported medium.

Safety fittings are designed to protect pipelines, gas equipment, containers from excess

high pressure, as well as to maintain the required pressure in the pipeline.

The shut-off valves must be sealed against external environment. Valves, taps, gate valves and butterfly valves intended for gas supply systems as shut-off valves (shut-off devices) must be designed for hydrocarbon gases. The tightness of the valves must correspond to class 1 according to GOST 9544.

Taps and butterfly valves must have rotation limiters and open-closed position indicators.

Shut-off valves are made of gray cast iron, ductile cast iron, carbon steel, and copper-based alloys.

Shut-off valves in accordance with GOST 4666 must have markings on the body and a distinctive color. The marking must contain the manufacturer's trademark, symbol or operating pressure, nominal passage and flow direction indicator, if necessary.

KPO on underground gas pipelines. Time frames for gas pipeline inspections. Paperwork.

Underground gas pipelines (made of metal and polyethylene pipes), which are in operation, must undergo technical inspection, incl. and comprehensive instrument examination. KPO, using instruments according to specially developed instructions, and, if necessary, pitting is also carried out. During technical inspection

gas pipelines, the actual location of gas pipelines, the condition of structures and equipment on them, tightness, condition protective coating and electrochemical protection.

When performing KPO, the following are checked:

location and, if necessary, depth of the gas pipeline;

gas pipeline tightness;

continuity and condition of the protective coating.

Technical inspection of underground steel gas pipelines is carried out:

with a service life of up to 25 years - at least once every 5 years. The first one a year after commissioning;

when operating for more than 25 years and before the expiration of the depreciation service life - at least 1 time in 3 years;

when included in the plan overhaul or replacement, as well as for protective coatings below the “very reinforced” type - at least once a year.

Extraordinary inspection of gas pipelines must be carried out:

If the service life exceeds for steel gas pipelines - 40 years, for semi-electrical pipelines - 50 years;

If leaks or breaks are detected in welded joints, through corrosion damage;

When the gas pipeline-ground potential decreases to values ​​below the minimum permissible, subject to a break in the operation of electrical protective installations for more than 1 month - in influence zones stray currents and over 6 months - in other cases provided for by DSTU B V.2.5-29:2006 " Engineering equipment houses and buildings. External networks and structures. Gas supply systems. Underground steel gas pipelines. General requirements to corrosion protection."

On gas pipelines that have a protective coating below the “very reinforced” type in addition to KPO, control drilling should be carried out to determine the condition of the pipes and the quality of the welded joints. Technical inspection of the condition of polyethylene gas pipelines is carried out within the time limits established for steel gas pipelines.

At KPO, a worksheet of 2 copies is compiled, one is given to the network section foreman.

Proving on a gas pipeline. Purpose of digging. The order of work. Preparation of documentation.

Inspection of underground steel gas pipelines in order to determine the condition of the protective coating, where the use of devices is hampered by industrial interference, is carried out by opening control holes on the gas pipelines with a length of at least 1.5 m every 500 m.

The locations for opening control pits and their number in industrial interference zones are determined by the gas enterprise or the enterprise operating the gas industry on its own.

For visual inspection, areas exposed to the greatest corrosion hazard, places where gas pipelines intersect with other underground utilities, and condensate collectors are selected. In this case, at least one hole must be opened for every kilometer of distribution gas pipelines and for every 200 m of a yard or intra-block gas pipeline, but at least one hole per driveway, yard or block.

Checking tightness and detecting gas leaks from underground gas pipelines during the period of soil freezing, as well as in areas located under improved road surfaces, should be done by drilling wells (or pinning) and then taking air samples from them.

On gas distribution pipelines and inlets, wells are drilled at the joints. If there are no joints, wells should be drilled every 2 m.

The depth of drilling them in winter time should be no less than the depth of soil freezing, in the warm season - correspond to the depth of pipe laying. Wells are laid at a distance of at least 0.5 m from the wall of the gas pipeline.

When using highly sensitive gas detectors, it is allowed to reduce the depth of the wells and place them along the axis of the gas pipeline, provided that the distance between the top of the pipe and the bottom of the well is at least 40 cm.

The use of open fire to determine the presence of gas in wells is not allowed.

Pit inspection of polyethylene gas pipelines is carried out only in places where steel inserts are installed.

At least 1 insert is checked per 1 km of gas distribution pipelines and at each quarterly distribution. To be able to inspect the joints of the connections of the polyethylene gas pipeline with the steel insert, the length of the pit should be 1.5-2 m. The opening of the pits is carried out using mechanisms or manually. The insulation and metal of steel inserts must be checked at least once every 5 years.

Based on the results of a technical inspection of steel and polyethylene gas pipelines, a protocol must be drawn up, which, taking into account the identified defects and assessment technical condition, an opinion should be given on the possibility of further operation of the gas pipeline, the need for timing of its repair and replacement. Information about the work performed and the results of the inspection is entered into the gas pipeline passport.