Purpose and arrangement of the carpet. Gas carpet AVK

A gas carpet is equipment that is necessary during the installation and operation of a gas pipeline. This element is necessary not only for underground installation, but also for laying communications on the surface. Externally, this element looks like a hatch with a rim. The diameter of such hatches may vary. The carpet presented on the website gasaquatek.ru is made from ultra-strong and reliable materials that can withstand even the strongest external influences. After all, this device performs the function of protecting the entire system. Usually the carpet is located near the area where the valves or valves are located. They are also installed in places where large quantities Condensation accumulates. The gas carpet must ensure safe and reliable transmission of gas through pipes directly to the consumer.

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

Purpose of the device

Regardless of what a gas carpet is made of or what diameter it has, this element is designed to perform specific functions.

1. It must create an obstacle to any illegal access to the gas main.
2. Protects the entire communication system from corrosion.
3. It is also installed for the purpose of free access for workers to the system, so that they can carry out maintenance of system elements, as well as their repair in case of any problems.
4. The cover provides the possibility of installing communications underground.

The walls of a gas 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 damage. If it were not there, not only pollution, but also foreign objects, which could lead to damage and breakdown 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 humidity, precipitation and other factors that can provoke oxidation processes, which will subsequently lead to equipment failure. 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 easy access to equipment. This may be maintenance of its elements or repair in case of breakdown. 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 repairs will be completed faster and with better quality. 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 it for them. Communications can be carried out with its help without preliminary work.

A gas carpet is a part necessary when laying both above-ground and underground gas main networks. This small hatch with a rim performs a protective function against external contamination and, at the same time, provides access for repairs and control measurements during operation of the gas pipeline.

How to properly use a gas carpet?

In Moscow, as in other Russian cities, the main method of laying a gas pipeline is underground. Gas carpets are used at the exit points of the most important components and cover various valves, valves and condensate collectors. A gas carpet provides not only protection from damage pipeline fittings, the entry of various contaminants and condensate, but also prevents unauthorized entry into the system, as well as gas leakage. The above means that it ensures the safety of gas delivery to the end consumer.

Carpets can be made from various materials. The choice of part of the required size will depend on where this device will be used and on what diameter pipe it will be installed. Today there are polymer-sand, steel and cast iron gas carpets. All of them will differ in their quality characteristics and have their own advantages and disadvantages.

Cast iron gas carpet: technical characteristics

Gas carpet: advantages

The polymer-sand gas carpet is lightweight, corrosion-resistant, durable, frost-resistant and durable. It is made from a special mixture of sand and polyethylene, taken in approximately equal proportions. Steel and cast iron carpets are also very durable, but cannot boast of high resistance to moisture, negative temperatures and other atmospheric influences. Over time, the material of such a carpet may undergo corrosive changes, which may threaten the safety of using the gas pipeline. This is why gas carpets need regular inspection, periodic painting and replacement when necessary.

Polymer-sand caps require less maintenance and effort. In addition, products made of steel and cast iron are much heavier than their polymer counterparts. Gradually components from modern materials are replacing the more familiar cast iron and steel analogues. Although, to protect gas valves and fittings, cast iron carpets are most often used. Gas carpets also differ in their dimensions - height and diameter, and can be used on pipes of various diameters.

Gas carpet installation

The gas carpet is installed on a concrete pad or on a base made of a more modern polymer material, in the case of a polymer-sand carpet. First, a discharge pipe is installed, after which the base itself is mounted on the compacted soil. Experts recommend installing the outlet tube in the center of the carpet so that it stands perpendicular to its base. The entire space around it is covered with sandy soil. Remember that the distance between the outlet device and the carpet cover must be at least 10 cm. After installation, the location of the gas carpet is marked using a wall indicator, which is fixed at a height of at least 2 meters.

In addition to gas carpets of various sizes, you can purchase any components for gas equipment, as well as accessories for household gas appliances and spare parts included in internal organization gas boiler, gas stove etc.

Gas network devices and elements include:

Shut-off valves;

Pipelines;

Condensate collectors;

Compensators;

Control conductors;

Control tubes;

Cases;

Directional signs.

Shut-off valves

Taps and valves are used as shut-off valves on gas pipelines; low pressure water seals can be used. On underground gas pipelines, shut-off valves are installed in wells.

They are used to be able to disconnect individual sections of gas pipelines or buildings.

On low-pressure gas pipelines, parts are installed with hydraulic seals, 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 to the surface of the earth. The gas is turned off when the water seal is filled with water through the pipe to a height exceeding the pressure in the gas pipeline.

The advantages of the water seal are simplicity of design and reliable shutdown; disadvantages - the possibility of water release when the pressure in the gas network increases and its self-shutdown if the accumulated water is not removed in a timely manner.

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

1 - body; 2 - drainage pipe; 3 - carpet cushion; 4 - carpet; 5 - contact plate; 6 - plug; 7 - grounding electrode; 8 - fitting with a plug for purge; 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 oil and natural gas. Strategic gas pipelines are intended to transport large volumes of gas over long distances - for export and to enterprises engaged in gas synthesis.

Rice. 2.2 Gas pipeline

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

Condensate collectors

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 collectors vary in size and design features depending on the gas pressure in the network and the volume of condensate.

Rice. 2.3 Condensate collectors

Compensators

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

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

Rubber-fabric compensators are used in heaving soils and earthquake-prone areas. They are made of rubber with layers of nylon fiber in the form of a helical hose, reinforced on the outside with nylon rope.

The use of stuffing box compensators on gas pipelines is strictly prohibited, because The design of this type of compensator 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 100 - 120 mm below the cover. The welding site of the control terminal is carefully isolated by filling it with a layer of bitumen.

Control conductors allow you to measure its electrical potential without opening the gas pipeline. This is necessary for timely leak detection direct current from tram, metro 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 rail tracks 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 crosses 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 in shape, with a diameter 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 led to the surface of the pipe, in which gas accumulates in case of leaks in a controlled area.

Rice. 2.6 Options for installing control tubes:

a) above the surface of the earth;

b) under the carpet.

Carpets

Currently, to ensure safety on gas pipelines underground laying A special protective device is used - a gas carpet. 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.

The gas carpet is a cylindrical protective dome-rim with a lid, made of steel, cast iron, polymer-sand mixture or polymer materials. The product is produced in various options 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 from a polymer-sand mixture by hot pressing.

The polymer-sand carpet on a gas pipeline almost completely replicates the characteristics of a cast iron product, but is much lighter and easier to install, is frost-resistant, and durable. Carpets are installed on concrete base(pillow). Many manufacturers offer carpets complete with a concrete pad and a repair kit consisting of a spare cover and rim.

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

Cases

At intersections with by rail, highways, driveways and other engineering structures, underground pipelines are laid in cases, the internal 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 heat-insulating 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 outermost rail. After laying the pipeline, the ends of the casing are sealed with tarred tow and filled with bitumen. The case is equipped with a control tube that goes under the carpet.

The case absorbs ground pressure and moving loads from transport.

1 – gas pipeline, 2 – casing, 3 – bitumen enamel, 4 – tarred hemp or jute, 5 – concrete

Rice. 2.9 Case for passing the gas pipeline through foundations and walls

Supports

For a gas pipeline laid inside a casing, supports can be provided (for steel gas pipelines - dielectric), which should ensure the safety of the gas pipeline and its insulation when the lash is pulled through the casing. The support spacing must be determined by calculation in accordance with the section “Calculation of gas pipelines for strength and stability” (SP 42-102, SP 42-103).

The supports can be sliding, roller (roller).

Rice. 2.10 Supports for gas pipelines

Information signs

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

Fig 2.11 Indication plate

Gas carpet is used in the gas industry, when laying gas pipelines, to provide access to service and control components of underground shut-off valves. The product does not require special maintenance, care or repair, and can withstand loads from 5 to 25 tons.
Our catalog presents models made of high-quality steel, grade 20 and polymer-sand material, which comply with all GOST standards. The D325 carpet with a cast rim can withstand heavy loads and can be built into highways and roads. If a non-standard height is required, we can make it to order.

Purpose of the equipment

Each gas and pipeline has control units, shut-off valves, and tubes for condensate drainage. To protect the equipment from illegal access, possible damage, and sediment contamination, a gas carpet is used. It serves as a kind of casing with a lid that can be locked with a special key, which ensures the safety of the gas pipeline.

Made from the following materials:

• Cast iron
• Steel
• Polymer

Cast iron has been used since the beginning of carpet production. It is heavy, has inert properties, but is quite fragile and not resistant to shock loads. A gas steel carpet, unlike cast iron, is ductile, impact-resistant, and lighter in weight. Inexpensive cost and excellent characteristics make it one of the most popular on the market.
This is the type of equipment that gas service repairmen recommend installing. Polymer has been produced relatively recently, but has already shown its excellent performance characteristics. Plastic is much lighter than cast iron and steel - its weight is from 8 kg. It does not rust, is shock-resistant, does not require painting to protect it from moisture, and can withstand high and low temperatures.

On the ILART website the equipment is presented in assortment:

• Large gas carpet, reinforced steel, with cast rim and cover.

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

Carpets for modern cast iron valves are necessary for more reliable protection certain parts of the mounted rods from possible contamination or accidental damage.

Let's consider the main advantages of the carpets used, they are as follows:

• high-quality special technological casting from durable cast iron;
• resistance to many possible damages;

The product is used for septic tanks and some treatment facilities. A plumbing carpet of this type provides convenient and easy access to the mandatory control, also measuring, some shut-off, including control valves, which are available on the pipeline, while at the same time reliably protects the 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 plumbing carpet is a cylindrical protective dome-rim with a special cover, made of high-quality reliable cast iron. This product is produced in a wide variety of required standard sizes, which allows it to be successfully used on modern pipelines of different diameters.

By the way, gas pipelines also use carpets specially cast from gray cast iron SCh-20, and there are also modern products made from a durable and lightweight polymer-sand mixture.

The cast iron carpet has a significant mass, and is quite easy to install; it is also frost-resistant and very durable. Typically, carpets are installed on a special concrete base (pad).

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