What are the current rules for the device and safe operation of steam and hot water pipelines

Pipelines are a special system of structures designed for the transportation, processing and disposal of substances in different aggregate states: gaseous, liquid and solid. All equipment is divided into different types and categories, which have individual technical characteristics and limitations.

Purpose of pipelines and their features

In steam pipelines, the working environment exceeds 100 degrees

Steam and hot water pipelines are designed for heating structures, warehouses and industrial premises. The most common material for a piping system is steel, but there are other materials as well.

The medium transported through these pipes, as a rule, has a temperature above 100 degrees. The parameter of overpressure in the pipeline communication reaches 1.6 MPa. New objects are made of steel, since the material has high resistance to mechanical stress, reliable in use and durable. To improve technical characteristics, materials are heat treated. This manipulation reduces the risk of water hammer. The applied heat treatment mode is indicated in the project documents.

However, heat treatment is not carried out in all cases. Exceptions occur for the following reasons:

  • The required technical parameters were achieved at the stage of pipes and parts production.
  • At the manufacturing stage, the pipe was subjected to heat treatment by hot shaping.

A water hammer is an emergency situation accompanied by a depressurization of the system, which entails a leak of steam and gas. Therefore, the technical characteristics must necessarily comply with the standards.

Categories of pipelines for steam and hot water, types of heating systems

Hot pipelines have 4 classifications. Technical parameters according to which the calculation of a particular communication is made:

  • Hot water pipelines (return and selling) - have the highest permissible temperature or pressure, the terrain and the type of pumping station are taken into account.
  • For a system that transports steam from boilers with operating parameters, a calculation is made of the temperature and pressure of the medium at the outlet.
  • For a water supply system transporting feed water after increased pressure dierators, the nominal pressure is taken into account, based on the technical parameters.
  • For steam lines powered by turbines, the pressure at idle, temperature and back pressure is important.
  • For the pipeline system transporting steam from the reduction-cooling and reduction units, the temperature and pressure of the medium is taken into account.

There are also exceptions where non-compliance with the rules is allowed, but they require a clear explanation for derogation from the laws.

Heating system classification

The division of heating networks is carried out according to the following factors:

  • design, availability of the scheme;
  • heat source;
  • type of gasket;
  • workspace.

Depending on the heat source:

  • decentralized (autonomous boiler rooms);
  • centralized (operate from a nuclear or thermal power plant).

Structures that transport hot media have one individual feature - a clear number of pipes in the entire pipeline system. This is due to the fact that in addition to moving the working environment, the structure must have a branch.

The steam pipeline has a complex system of work and, accordingly, a design. This is due to the fact that the working environment reaches a temperature that exceeds the permissible water temperature. As a result of strong heating, if the structure is not designed correctly, deformation of the pipes is possible. Also take into account the formation of condensate on the walls of pipes and parts.

According to the principle of laying a heating network, there are:

  • underground (hidden);
  • aboveground (open).

Open pipeline systems, as a rule, are carried out in those conditions when it is necessary to secure communications from mobile (seismically active) underground soils, as well as in densely built-up areas.

Rules for the construction and safe operation of steam and hot water pipes

The design and installation of the system is carried out in accordance with building codes and regulations. When making calculations, the following parameters are taken into account:

  • the mass of the pipeline;
  • permissible temperature regime;
  • the size of the working and permissible pressure;
  • expansion of metals under the influence of high temperatures.

Based on the data obtained, specialists calculate the operational life of the pipeline and record it in the passport. The pipeline must be designed in such a way that it is not difficult to carry out control and regular medical examinations. Pipeline elements are welded.

Flanged and threaded connections are used if the parts are equipped with flanges. It is also worth considering that the parts of the pipeline are pre-treated with a means that prevents corrosion processes. All areas where the temperature is above 55 degrees must be thermally insulated.

Concealed installation

When laying a pipeline in a semi-through trench, it must be borne in mind that its height must be at least 1.5 meters, and the minimum allowable interval between insulated pipes is approximately 60 cm.

The sections on which the shut-off valves are mounted are placed in the thickened places of the tunnel in order to regularly inspect and eliminate breakdowns.

Ground method of laying communications

If an open installation of a pipeline is carried out, through which liquid and steam of high temperatures will move, you must strictly follow the rules prescribed in SNiP. Surface installation, in contrast to hidden installation, allows for joint laying of different types of communication networks.

Most often, the onshore pipeline is carried out on the territory of industrial enterprises. They are involved only in cases where there is no opportunity to conduct communications in a hidden way.

Ground installation is carried out in the following cases:

  • geographically, the site is located in permafrost;
  • high level of stagnant groundwater;
  • seismic activity.

The open method of installation has a significant advantage in comparison with the underground one - savings in financial costs, as a rule, they are less than 40%.

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