Heating in high-rise building - a complex engineering system which correct operation is feasible only if the set parameters Regulatory Compliance. These parameters include the pressure in the high-rise building heating system, which achieves both security and efficiency, and durability.
The essence of the phenomenon
So, it was pressure apartment building heating system It determines how effective it will be. Created water pressure ensures that the heat transfer fluid will reach the most remote radiators and pipes, the temperature even throughout.
The optimum value for this parameter also reduces heat losses, water is in the radiator at the same temperature, which was achieved in the boiler.
kind
The water pressure in a private home or other building is divided into several groups:
- Static. This parameter determines how hard the water "presses" on the radiators and pipes at different heights.
- Dynamic. Formed in the course of circulation of the coolant circuit, that it contributes to the wear elements.
- Max. The critical value, the achievement of which, it is likely provoke an accident.
Most Russian homes the figure stands at 7 atmospheres, it is enough for correct functioning. However, certain phenomena change value (critical low level - 5 atmospheres), because of which undesired effects occur.
What does it depend on?
The pressure in the hot water heating system of a private house varies depending on several factors:
- The degree of wear of the heating devices. Aging equipment invariably leads to a drop in the level of efficiency. Only one way out - the purchase of new appliances (mainly this concerns pumps).
- The degree of encrustation devices salts rigidity and sludge. Yield - coolant quality control, periodic flushing of the heating system.
- Power units, feed coolant. For high-rise buildings of these units are heating units, for cottages - circulation pumps. The farther the building is located on the substation, the worse things are.
- Location of the apartment. Of course, in ideal conditions, the pressure in each tube, and each radiator the same, but to achieve this is not always possible. Minimum pressure is fixed in the corners of rooms - the most distant from the main risers.
- The diameters of the pipes. If in the process of repairing the residents replaced the pipe in an apartment on the product with a larger diameter than that of the inlet conduit, the value does not change, but only slightly decreases the rate of water movement. Interestingly, the plastic tube during operation may gradually become larger initial diameter, which does not affect the pressure in the system. However, it happens that the inner layer of the multilayer pipe temperature exfoliate and clogs the passage. Then circulating pressure drops sharply, sometimes to zero (it happens very rarely, if the building is located near the boiler: temperature is higher than the normative for metal and plastic).
See also: causes a pressure drop in boilers.
Common causes pressure drop
If you heat your home there are problems, it is likely that the case is connected with the pressure. In most cases, there is airing system, circulating pressure drops, sometimes to zero. Solved due to bypass the coolant in the opposite direction to "reset", ie close the supply line after the valve opens the drain valve or plug. Reverse pressure easily released into the air atmosphere. The second reason for the prevalence of: feeding the sludge clogged valves on the risers (designed for riser pressure control valves are installed, rather than ball valves) and depressurization system heating. The most vulnerable places in this regard are compounds, and joints. Of course, sometimes bursting pipes themselves, if they have already worked out the service life have become dilapidated, rusty, thinned. Leakage leads to a static pressure drop, if this option is correct, the problem lies elsewhere. To simplify the search process, the main segments are checked one by one, he is cut off, recovered, is sealed when the defective portion.
If on its own can not find a leak, it is necessary to involve experts. They adhere to different approach: suspicious portion is drained and filled with air, whose output is able to determine even microcrack.
Even if such a method shows the serviceability of the pipeline, the problem probably lies in the boiler:
- The heat exchange circuit scum covered. This problem is particularly relevant for systems in which the heat transfer fluid does not differ high quality (hard water). Sheer scale on the heat exchanger does not affect the circulating pressure (influence on boiler efficiency), but the scale particles exfoliated from the walls heat exchanger, are dangerous: they clog filters, automatic valves, saddle valve, causing a pressure drop, sometimes a complete misalignment heating systems;
- Damage to the surge tank (or airing leads to a sharp increase as a consequence - the impulse and drain respectively);
- Destruction of heat exchanger due to the water hammer (mainly due to the installation of ball valves, instead of the recommended recharge valves for heating system);
- Microcracks in the exchange tank circuit, whose appearance is initially triggered by the production of poor quality or long period of operation.
It is necessary to eliminate leaks, blockages, and only then raise the pressure to operating. Service heating operation is carried out only after reset to a static pressure or optionally emptied completely. Such works include:
- Cleaning the filter;
- Replacement of faulty devices;
- Draining the water system in connection with the termination of the gas supply in the winter (emergency operation to gas pipeline) to prevent freezing;
- Flushing the heating system of deposits and limescale.
Testing
In order to verify compliance with the values of the standards, some conscious communal services carried out hydraulic tests of heating system:
- Testing "the cold". Is filled all the main elements of cold water (temperature below 5 degrees Celsius), made fixed parameter. Paragraph 4.6 (INTERNAL SANITARY SYSTEMS snip-3-05-01-85): Test water heating and heating must be performed at the disconnected boilers and expansion vessels by hydrostatic pressure equal to 1.5 the working pressure but not less than 0.2 MPa (2 kgf / cm) at the lowest point system. The system recognizes passed the test if, within 5 min under the location of its test pressure drop in pressure not exceed 0.02 MPa (0.2 kgf / cm) and there are no leaks in the welds, pipes, threaded connections, fittings, heating devices and equipment. If you are unable to meet these standards, launching permitted. If the air temperature is below 5, the test is carried out with compressed air.
- Testing "on hot". As a rule, it is carried out before the official start of the heating season. Hot coolant is pumped at a pressure close to critical for a particular system. No problems says that during the heating season, there will be no incidents.
preventive measures
It was not necessary urgently to raise or lower the pressure should be checked regularly Mechanical cleaning of filters for the formation of blockages. Also do not forget about the expansion tank, if necessary - the air is pumped up to the value indicated in the passport of the boiler or the expansion vessel. It is mandatory to heating system must be equipped with safety group (automatic air + automatic pressure ejector) through which air is vented easily, descend excess coolant. Example prefabrication security group on the first photo in this article.
