Pipeline laying: methods and technologies

The development of industry and modern urban economy is absolutely impossible without the use of pipelines of different purposes. Uninterrupted operation of heating systems for water supply, sewerage, gas, oil pipelines, etc. can be ensured only if the required technologies and regulations are observed while laying them. There are many ways of assembling pipelines.

What technologies can be used

There are the following basic methods of laying pipelines:

• The open method assumes the assembly of the mains along the supports, as well as in the non-flowing and through-flow collectors.
• Closed or trenchless method. It presupposes the laying of pipelines underground without preliminary opening of the ground.
• The hidden method. In this case, the pipes stretch along the dug trenches.

For the assembly of highways depending on the characteristics of the transported environment, installation methods and external conditions, pipes made of different materials can be used: concrete, metal, plastic, ceramic, asbestos. In cities, laying of water supply pipelines can be carried out in one trench with other communications (heating mains, cable systems, etc.). This allows the use of both trench and channel technology.

Features of the open method of laying pipelines

This method can be used to lay heating, water supply, sewerage, etc. The use of non-passable channels under the trunk line in comparison with the trench method has one indisputable advantage. Pipes laid in them are not exposed to ground pressure during punching or movement, and therefore, serve longer. The disadvantage of this technique is considered to be difficult access to the mains if it is necessary to repair them.

The laying of the pipeline in the passageways is more expensive. However, in this case, specialists of service companies have the opportunity to access highways without the need for excavation.

Above the ground surface, pipes are usually laid only in undeveloped areas of settlements, as temporary highways, etc. Various kinds of concrete and metal structures, overpasses, walls of structures, etc., can support them.

Methods of laying pipelines in cities can be different. But in any case, the mains for human settlements are pulled outside the pressure zone in the ground from structures and buildings. This contributes to the preservation of foundations in the event of a breakthrough. All underground urban engineering communications are divided into three large groups: main, transit and distribution. The first variety includes all the main communication networks of the settlement. Transit pipelines pass through the city, but they are not used in any way. Distributive roads are called trunk lines that depart from the main directly to buildings.

Hidden method of laying

The construction of pipelines using this technique is performed most often. The main advantage of laying pipes in trenches is its relative cheapness. However, the assembly technology in this case must be strictly observed. After all, access to pipes in this case is difficult and it is necessary to ensure that repair of the pipeline was required as rarely as possible.

Rules of work with hidden laying

Trenches under the trunk can be used shallow or deep. In the first case, the laying of the pipeline is carried out at 50-90 cm. When using the deep method, the trenches are digested below the ground freezing. The laying of industrial pipelines can be carried out at a depth of up to 5 m. The rules for laying the lines are as follows:

1. If the soil is dense, the pipes are laid directly on it.
2. When laying at a depth of more than 4 m, or if the pipes are made of not too strong material, they arrange an artificial substrate. They also act on condition of assembling the main lines in complex hydrogeological conditions.
3. The bottom of the trenches is prepared in such a way that the pipes come into contact with it all the way. The existing voids are covered with local soils or sand.
4. In the presence of groundwater in the lowest places are arranged pits for their pumping.

Hidden method of laying: technology features

The technology of building highways is selected, including depending on the pipe of which material is used. Polymer is welded to several pieces (up to a length of 18-24 m) directly near the storage object, and then delivered to the location of the gasket. Here in the summer, they are harvested in a continuous thread, after which they are placed in a trench. Installation is carried out with the help of mobile welding installations. In winter, pipes are laid in a trench one at a time and connected by gluing or using rubber rings.

The construction of ceramic pipelines on a gradient is made from top to bottom. Before starting the installation, the pipes are inspected for chips. They are connected by the socket method with the sealing of the bituminous strand and the lock device from the cement slurry. Approximately the same way fit and concrete pipes. As a seal, a rubber ring can be used in this case.

Asbestos cement main pipelines with pressure up to 0,6 MPa are assembled using double-bit asbestos cement clutches, and with pressure up to 0,9 MPa - using cast-iron flanged ones. Non-pressure pipelines are conducted using cylindrical couplings. Steel lines are laid using welding.

Trenchless method

Pipeline laying by this method is used mainly when it is impossible to assemble by concealed technology. For example, this is how the lines are drawn under busy roads, railways, external engineering communications, etc. There are the following methods of trenchless laying of pipelines:

• Puncture;
• Forcing;
• Horizontal drilling;
• Panel excavation.

Puncture by puncture

This technology draws the main pipelines on loamy and clay soils. When using it, it is possible to lay pipelines up to 60 m in length. This procedure is as follows:

• A steel tip is put on the pipe;
• At a certain distance from the obstacle digs a foundation pit and installs a hydraulic jack on the supports;
• A pipe is lowered into the foundation pit with a pipe of a smaller diameter inserted into it - "ramrod";
• A step-by-step puncture of the soil is carried out.

When using this technique, the ground is not taken out. In the process of puncture, it simply compacts along the circumference of the tube.

The method of pushing and the technology of panel penetration

These technologies are also quite often used when assembling pipelines under obstacles. Pipeline laying by the method of pushing allows you to overcome obstacles up to a hundred meters. In this case, the pipe is pressed open into the ground by the open end. The earth plug formed inside it is removed.

The pass shield consists of a supporting, knife and tail part. The second provides the cutting of the rock and the deepening of the structure into the massif. The bearing part looks like a ring and is designed to give the structure the necessary rigidity. In the tail part there is a control panel for the shield.

Directional Horizontal Drilling

This method is considered the most costly. But he has one absolute advantage. Using this technology, it is possible to pass even the most dense soils. Drilling in this case is made by special rods, connected by hinges. It is possible to drill at a speed of 1.5-19 m / h. Unfortunately, this technology can not be used in the presence of groundwater on the site.

Thus, the choice of methods for laying pipelines depends on the characteristics of the soil, the material of the pipe manufacturing, and the production need. In any case, the technology of building highways should be observed in accuracy. A quality pipeline is a guarantee of uninterrupted operation of industrial enterprises and city utilities.