For the delivery of energy heat resources from generation sources to remote consumers, it is necessary to use special transport networks - heating mains. These are trunk lines through which, in particular, hot water is transferred to ensure the operation of the communal heating system. Despite the massive transition of private homeowners to autonomous hot water systems, heating pipelines are also used in this area. Installation is carried out according to various schemes - both underground and above it. But the most important thing is to comply with the rules for laying and operating such lines.
Requirements for used pipes
The pipeline material should correspond to temperature loads and pressure in the line. At a minimum, it should maintain performance at 95 ° C. As for pressure, a level of 1.5 atmospheres is considered normative for autonomous heating. In the installation of heating mains for heating with such requirements, the following pipes are usually used:
- Steel galvanized. There are practically no temperature restrictions, and the limiting pressure indicators are about 12 atmospheres. The mechanical strength and resistance to deforming loads can also be emphasized. However, steel can cause a lot of problems due to threaded connections, not to mention the fact that metal is, in principle, quite a laborious material from the point of view of physical handling during installation.
- Polypropylene pipes. There are temperature restrictions (up to 95 ° C), and the maximum pressure is 9 atmospheres. However, the combination of mechanical strength, tightness at the joints and modest mass compensates for these shortcomings.
- Plastic pipes. The optimal solution, which is characterized by durability, flexibility in installation and practicality. Such pipes for heating mains are used both in industry and in private households.
Insulation for heating main
Even correctly selected pipes do not guarantee the conservation of heat during transport. This property depends on the coverage of the circuit - heat insulator. Today, for such purposes, the following materials are used:
- Glass wool. It goes well with metal-plastic, has a low density and is cheap. But effective heat saving of glass wool can provide only in combination with roofing material or fiberglass. Accordingly, both costs and time for installation work increase.
- Basalt insulator. It has a cylindrical shape, characterized by ease of installation and high thermal insulation performance. The only negative - in itself is expensive.
- Polyurethane foam (PPU). A kind of plastic that demonstrates resistance to temperature extremes. But the main advantage of this material is different. There are practically no restrictions for the installation of heating pipelines in terms of pipeline complexity. The insulator can be used even in liquid form, which allows them to precisely process hard-to-reach local areas.
- Crosslinked polyethylene. A polymer-based structural insulator, among which the main advantages are strength, resistance to thermophysical loads, chemical and mechanical stresses.
Technology of installation of heating main
The organization of the main heat supply system is carried out in several stages:
- Design. Based on the results of a comprehensive survey of the direction of laying the line, taking into account the requirements for transporting the coolant, a list of materials, their operational characteristics, and also the installation configuration are determined.
- Preparation for laying. Technical conditions are being created for future pipe installation. The laying area is cleared and, if necessary, trays (channels) are installed for rear protection of the circuit.
- Installation of pipes. Direct installation of the heating pipeline is carried out, in which the substrate and insulation material are attached to the prepared trays. Clamps, anodized protective equipment and fixing hardware may be used for this.
- Testing and commissioning are being carried out.
Heating Routing Configurations
Several pipelines can be laid in one line. In this regard, distinguish one-and two-pipe, as well as radiation method of laying. In the first case, only one circuit is used, in the second, two channels, respectively. During radial installation of the heating main, several circuits are connected to the collector, from which flows are sent to individual consumption points. This system is advantageous in that it allows you to regulate the flow, alternately loading and distributing them depending on current needs.
Features of channelless laying
The main difference between this method of organizing heating systems is the rejection of bearing gaskets. That is, the installation of trays for a heating main of this type is not necessary - the installation is carried out directly on the ground. The lack of additional protection and support for the pipeline is compensated by the use of special fittings in polyurethane foam insulation with a polyethylene sheath. Also, for such networks, an online remote monitoring system is provided, which constantly monitors the state of isolation.
Repair of a heating main
Maintenance with diagnostics and repair procedures can be carried out both in the planned order according to the schedule, and according to the signal from the monitoring equipment. Repair and restoration operations are performed in the following order:
- Localization of damage using special equipment.
- Dismantling of tray floors.
- Dismantling the faulty area.
- Replacement, repair or addition of the problem area with the necessary element. Often, electric welding installation of a heating main is carried out at a point with pipe damage in a gas environment.
- Cleaning the contour of dirt and foreign objects.
- Pressure testing aimed at checking for leaks after repair.
- Assembly of the structure.
Conclusion
Heating pipelines differ from ordinary pipelines in their large diameter and obligatory ability to serve hot environments. This also explains the increased requirements for the materials used and the conditions for laying. In the domestic sphere, homeowners are faced with the installation of heating pipelines during the organization of hot water supply. But even in this case, pipes and components of a smaller format are used - with an eyeliner from secondary distribution lines. In terms of technological support, regulatory tools can correspond to industrial networks - at least in terms of functionality. Thermostats, shutoff valves of manifolds, pressure and temperature sensors are also used to control and control flows.