Installation of carpets on gas pipelines. Control and maintenance of gas pipelines

The cast-iron plumbing carpet is an anti-vandal special hatch (Carpet) - it is a reliable and convenient protective device on any modern water supply system, as well as a gas pipeline underground laying.

Cast iron carpets for modern valves are necessary for more reliable protection certain parts of the mounted stems from possible contamination or accidental damage.

Consider the main advantages of the used carpets, they are as follows:

• high-quality special technological casting made of durable cast iron;
• resistance to many possible damage;

The product is used for septic tanks and some treatment facilities... A tap carpet of this type provides a convenient and easy access to the mandatory control, also measuring, some shut-off valves, including control valves, which are on the pipeline, at the same time reliably protects pipes / fittings from unplanned penetration and damage.

• The color of the carpet we offer is black;
• It is made of durable cast iron carpet;
• The plumbing carpet consists of a special body, a cover, and an axis.

What is a carpet on a modern sewer?

The tap carpet is a cylindrical protective dome-rim with a special cover, made of high-quality reliable cast iron. This product is manufactured in the most different options required standard sizes, which makes it possible to successfully use it on modern pipelines of different diameters.

By the way, gas pipelines also use carpets specially cast from gray cast iron SCH-20; there are also modern products made of durable and light polymer-sand mixture.

The cast-iron carpet has a significant mass, and it is quite easy to install, moreover, it is frost-resistant, very durable. Usually the installation of carpets is carried out on a special concrete base(pillow).

We offer our customers to buy quality products from the most worthy manufacturer. The cover and the body of the product itself are made of durable ductile iron, and the material of this clamp and rivet is high-strength steel. By ordering carpets from us, you will be sure of their high quality, durability and reliability!

A product providing access to underground shut-off valves. It is made in the form of a cylindrical dome with a cover made of steel, cast iron, sand-polymer mixture or polymer materials.

By the way, plumbing carpets are not very different from gas ones, their design is almost the same.

Gas types of carpets:

• functional;
• protective.

Functional purpose of carpets

Carpets are classified as special pipeline equipment that are designed to equip a gas pipeline. They provide access to measurement, control and regulation equipment, which are located underground, as well as to stop valves, which must be installed on gas and pipelines.

Carpets are also referred to as protective devices that ensure the safety of gas and pipelines. This is a kind of casing that protects control equipment and other elements from contamination, precipitation and possible mechanical damage. It also prevents unauthorized entry. This is due to the fact that the cover of the carpet is securely bolted, and it can only be opened with the appropriate key.

On modern pipelines, carpets made of cast iron and a sand-polymer mixture are mainly used. Compared to cast iron carpet, mix carpets are much lighter, but also durable, frost-resistant and are in no way inferior to cast iron in terms of characteristics.
Carpets are installed on a concrete base called a “cushion”. "Pillows" are also made to fit. Installation is very simple, and it can be in operation without replacement for more than 25-30 years.

At the Severozapad Steel Structures Plant, gas carpets are made of various materials with a corresponding size "pillow", which is included in the set.

Devices and elements of gas networks include:

Shut-off valves;

Pipelines;

Condensate traps;

Compensators;

Control conductors;

Control tubes;

Cases;

Directional signs.

Shut-off valves

As shut-off valves on gas pipelines, taps and valves are used, on gas pipelines low pressure water locks can be used. On underground gas pipelines, shut-off valves are installed in wells.

They are used for the possibility of disconnecting individual sections of gas pipelines or buildings.

On low-pressure gas pipelines, parts are installed with hydraulic locks, which are small vertical cylindrical vessels with two obliquely welded branches for connection to the gas pipeline and a pipe welded to the upper bottom and brought out to the ground surface. The gas is turned off when the hydraulic seal is filled with water through the pipe to a height exceeding the pressure in the gas pipeline.

Advantages of the hydraulic seal - simplicity of design and reliability of shutdown; disadvantages - the possibility of water ejection when the pressure in the gas network rises and its self-shutdown in case of untimely removal of the accumulated water.

The disadvantage of hydraulic locks is the duration of operations for filling and pumping out water with a pump.

1 - case; 2 - drainage tube; 3 - carpet pillow; 4 - carpet; 5 - contact plate; 6 - cork; 7 - grounding electrode; 8 - nozzle with a plug for purging; 9 - casing

Rice. 2.1 a) water seal for gas pipelines from 50 to 150 mm

b) water seal for gas pipelines from 150 to 300 mm

Pipelines

A pipeline is an artificial structure designed to transport gaseous and liquid substances, as well as solid fuel and other solids in the form of a solution under the influence of pressure differences in the cross-sections of the pipe.

Gas pipeline - intended for transportation of associated petroleum and natural gas. Strategic gas pipelines are designed to transmit large volumes of gas over long distances - for export and for gas synthesis enterprises.

Rice. 2.2 Gas pipeline

The classification of gas pipelines was discussed in the previous chapter.

Condensate traps

At the lowest points of the longitudinal profile of the gas pipeline, condensate collectors are installed, the capacity of which depends on the diameter of the gas pipeline and the amount of water accumulating in them. This water enters through leaks that form during operation. Condensate traps vary in size and design features depending on the gas pressure in the network and the volume of condensate.

Rice. 2.3 Condensate traps

Compensators

Compensators are movable elements of pipelines designed to compensate for movements arising from vibrations and thermal elongations. They serve to protect gas pipelines and their equipment from temperature stresses, as well as the possibility of installing and repairing fittings - lens (Fig. 2.3), rubber-fabric, axial wavy and bent (U-shaped), bellows.

Lens expansion joints are made of thin sheet steel in the form of separate semi-lenses welded together, the space between which is filled with bitumen. Lens expansion joints are installed in a somewhat compressed state, taking into account their maximum compensating ability and axial forces.

Rubber-fabric expansion joints are used in heaving soils and earthquake-prone areas. They are made of rubber with layers of nylon fiber in the form of a screw-like hose, reinforced from the outside with a nylon rope.

The use of stuffing box expansion joints on gas pipelines is strictly prohibited, because the design of this type of expansion joint does not guarantee its tightness for a long time.

Rice. 2.4 Lens compensator

Control conductors

The control conductor is a steel rod with a diameter of 8 - 12 mm, welded to a steel pipeline. The length of the rod is taken depending on the depth of the pipeline, so that the free end of the rod in the carpet is below the cover by 100 - 120 mm. The welding point of the test lead is carefully insulated by pouring a layer of bitumen.

Control conductors allow measuring its electrical potential without opening the gas pipeline. This is necessary for timely detection of DC leakage from tram, subway and other sources to underground gas pipelines. Leakage currents cause electrochemical corrosion of gas pipelines.

Control conductors are installed on sections of gas pipelines located near the track of a tram or electric train at a distance of 200 m from each other, as well as against the suction points of the rail network and in places where the gas pipeline intersects electric rail tracks, on both sides.

Control tubes

In some places, control tubes are installed above the welded joints of gas pipelines. They are designed to quickly detect gas leaks from an underground gas pipeline. This device consists of a metal casing 350 mm long, semi-cylindrical, with a diameter of large diameter pipes 200 mm. From the casing, laid on a layer of crushed stone or gravel, a pipe with a diameter of 60 mm is diverted to the surface of the pipe, in which gas accumulates during leaks in a controlled place.

Rice. 2.6 Installation options for test tubes:

a) above the surface of the earth;

b) under the carpet.

Carpets

At present, a special protective device, a gas carpet, is used to ensure safety on underground gas pipelines. Its main purpose is access to control, measuring, shut-off and control valves installed on the pipeline, and its protection from unauthorized entry and damage.

A gas carpet is a cylindrical protective dome-rim with a cover made of steel, cast iron, polymer-sand mixture or polymer materials. The product is manufactured in various standard sizes, which allows it to be used on pipelines of different diameters. Gas pipelines also use carpets cast from gray cast iron SCH-20 and modern products made of polymer-sand mixture by hot pressing.

The polymer-sand carpet on the gas pipeline almost completely repeats the cast-iron product in terms of characteristics, but it is much easier and easier to install, frost-resistant, durable. Installation of carpets is carried out on a concrete base (pillow). Many manufacturers offer rugs complete with a concrete pad and a repair kit consisting of a replacement cover and rim.

Rice. 2.7 Cast iron carpet Rice 2.8 Polymer-sand carpet

Cases

At intersections with by rail, by road, by driveways and other engineering structures, underground pipelines are laid in cases, the inner diameter of which is usually 100-200 mm larger than the outer diameter of the pipeline laid in it (taking into account the thickness of the thermal insulation structure). The ends of the case must extend beyond the intersection by at least 0.5 m in each direction, but not less than 5 m from the head of the outer rail. After laying the pipeline, the ends of the case are sealed with tarred tow and poured with bitumen. The case is equipped with a control tube led out under the carpet.

The case perceives ground pressure and moving loads from transport.

1 - gas pipeline, 2 - case, 3 - bitumen enamel, 4 - tarred hemp or jute, 5 - concrete

Rice. 2.9 Case for pipeline passage through foundations and walls

Support

For a gas pipeline laid inside the case, it is possible to provide supports (for steel gas pipelines - dielectric), which should ensure the safety of the gas pipeline and its insulation when pulling the whip in the case. The step of the supports should be determined by calculation in accordance with the section "Calculation of gas pipelines for strength and stability" (SP 42-102, SP 42-103).

Supports can be sliding, roller (roller).

Rice. 2.10 Supports for gas pipelines

Directional signs

To determine the location of the gas pipeline, it is necessary to provide for the installation of indicator plates above or near the gas pipeline, which are placed on the walls of permanent buildings and structures, fences, power transmission line supports, on special reference posts. Gas pipeline route outside settlements indicated by reference pillars on the right side no closer than 1 m from the axis of the gas pipeline on straight sections within the visibility range of no more than 500 m.

Fig 2.11 Information plate

A carpet is a product that provides access to underground shut-off valves. In addition, it protects pipeline elements from contamination, precipitation and unauthorized access. The carpet is installed directly into the ground, while no more than 20 cm of all equipment remains visible above the ground.

PE carpet device

The main part of the device is made of polyethylene, the lid is made of cast iron. The handle of the gas extension rod is brought under the carpet. ball valve... Thus, it represents the head of a small well. Its lid is securely locked with a bolt, which can only be opened with an appropriate key.

PE carpets are indispensable in the construction of a modern gas or water supply system. They are easy to install and durable, do not require replacement for at least 30 years. For more information about the range of goods and other fittings for HDPE pipes, check with our consultants by phone, you can also find out the hundred presented on the website or send a request by e-mail.

A gas carpet is a piece of equipment that is necessary when laying and operating a gas pipeline. This element is necessary not only for underground laying, but also for laying communications on the surface. Outwardly, this element looks like a hatch with a rim. These hatches may have different diameters. The carpet presented on the gasaquatek.ru website is made of heavy-duty and reliable materials that are able to withstand even the strongest outside influences. After all, this device performs the function of protecting the entire system. Usually the carpet is located near the place where the valves or latches are located. They are also installed in those places where in large quantities condensation accumulates. The gas carpet must ensure safe and reliable transmission of gas through pipes directly to the consumer.

Gas carpets differ in price, as they are made from different materials. Also, the price depends on the diameter of the device. When choosing a carpet, you should be guided by the goals for which it will be intended, as well as your preferences. The main thing is that the installation of the element is done according to all the rules. Its reliable and stable installation is very important, as its use will depend on it. Before installing the carpet, you need to prepare a concrete pad. Its diameter must match the dimensions of the selected element. The base is allowed to be made of polymer. But this is allowed only if you have chosen a carpet made of sand-polymer raw materials.

Appointment of the device

No matter what it is made of gas carpet, and what diameter it has, this element is designed to perform specific functions.

1. He must create an obstacle to any illegal access to the gas pipeline.
2. Protects the entire communications system from corrosion.
3. It is also installed for the purpose of free access of workers to the system, so that they can carry out maintenance of system elements, as well as their repair in case of any malfunctions.
4. Cover provides the ability to install communications underground.

The gas walls of the carpet are very strong and reliable. It is equipped with a locking cover that reliably protects not only the fittings, but the entire system as a whole from intruders. In addition, the carpet protects the system from breakage. If it were not for it, not only pollution could easily get inside, but also foreign objects that could lead to damage and breakage of pipes and other components of the system. Another very important function of the carpet is to provide anti-corrosion protection to the system. It protects it from moisture, atmospheric precipitation and other factors that can provoke oxidation processes, which will subsequently lead to equipment breakdown. The presence of a carpet can completely protect the entire system from factors that can cause corrosion.

Maintenance and repair

From time to time, situations arise when workers need convenient access to equipment. This can be the maintenance of its elements or repair in the event of a breakdown. In order to be able to carry out the work, specialists need to get to the valves and shut-off elements. Thanks to the carpet renovation work pass more efficiently. It is easier for specialists to work with system elements. This means that the repair will be faster and better. Usually, when laying gas pipes underground, there is a place that is often used for laying communications. Workers must also have access to these communications. The carpet provides them. Communication with its help can be carried out without preliminary work.