To distribute the coolant flows in multi-storey buildings, vertically placed pipes are used, which have a characteristic name - a heating riser. They are laid through a through route along all floors of the building and across apartments, in each of which a branch is made for connecting radiator batteries. Taking into account the fact that the service life of such pipes rarely exceeds 25-30 years, special attention is paid to their renewal. To do this, you need to know the design features of the riser along with its constituent components. In addition, you will have to familiarize yourself with the issues of disconnecting and replacing the heating risers in the apartment.
Functional purpose
Before updating the riser structure, first deal with its functional purpose, which is as follows:
- distribution of the heat carrier (flows of heated water) among consumers;
- its delivery to the heating zones in the apartment (batteries);
- balancing the hydraulic load.
The indicators of the functionality of the common riser for the house are directly related to the peculiarities of the distribution of the coolant in individual apartments.
In the entrances of typical city houses, on average, from 4 to 8 heating verticals are provided (in multi-room apartments, their number reaches 4 pieces). In most of the schemes used, the riser serves to deliver hot coolant and to remove cooled water masses. Such organization of transportation is typical for a one-pipe system containing a "return". With two-pipe wiring, each of these functions is performed by a separate branch of the main line passing through the floor and ceiling of the apartment.
Balancing the hydraulic load is necessary to equalize the pressure across the entire height of the riser structure. The need for this is due to the complexity of the water flow distribution scheme, which has many bends and bends. It will be necessary to take this factor into account when connecting additional batteries on your own, made during a system overhaul, for example.
The choice of material for vertical heating pipes
A stand-up heating system for residential buildings is an outdated scheme that is still found in most buildings of the last century. It was developed taking into account the layout of the apartments, and its change after the end of the pipe service life is almost impossible. The only thing that is allowed to the owner in these conditions is to replace them by choosing a more modern and reliable material. Before buying pipe products, it is important to pay attention to their diameter, which is chosen equal to the same indicator at the bends.
The rest of the problems with the renewal of pipes that have worked out their life are in taking into account the conditions under which it is supposed to operate new products. They have to:
- withstand the high temperature of the coolant, as well as its sharp drops;
- do not collapse at increased pressure in the system and possible hydraulic shocks;
- allow the possibility of insulation in open areas of wiring (in multi-storey private houses, for example).
All these requirements are met by both traditional steel and modern polypropylene or metal-plastic pipes.The user needs to select the preferred option by comparing the characteristics of these products. In this case, it is important to take into account the following features of the presented options, which appear when comparing them:
- polyethylene pipes are very convenient for installation and maintenance, and also have a relatively low price;
- they are not subject to corrosion and, unlike metal counterparts, have a long service life;
- pipes made of cross-linked polyethylene (SP) and their metal-plastic analogs are stronger and more durable, but their cost is higher than that of other product samples.
Strong and stainless copper pipes have the highest heat transfer, but their significant drawback is their high cost. The disadvantages of metal-plastic products include the low reliability of the connection in the case of using fittings. With significant pressure drops in these places, leaks may occur.
The best option is polypropylene pipes with a high strength index, marked as PN25. However, they can be used at temperatures no higher than 90 degrees. If such conditions cannot be ensured, steel pipes that are not very durable should be chosen.
DIY heating riser installation
Replacing heating in apartment buildings boils down to moving pipes to a more suitable place with their complete renovation. It is best to do this not during the heating season, when the house is disconnected from the thermal substation. Before changing them to new samples, you will need to solve the following issues:
- obtain permission from the heat supply organization (UK);
- prepare pipe blanks and a new wiring diagram.
In winter, the issue of replacement is additionally coordinated with the residents of apartments connected to the riser.
Features of replacing and connecting radiators
When replacing a riser, the heating elements (batteries) connected to it should be simultaneously updated, guided by a previously drawn up switching diagram. You will also need to prepare a full set of equipment, without which the radiators will not be able to effectively heat the room. Their harness includes the following elements:
- shut-off valves used for dosing volumes of the coolant in the batteries and their overlap;
- thermostat, the main purpose of which is automatic stabilization of the heat flow temperature;
- mechanism for eliminating traffic jams (Mayevsky crane).
For a one-pipe system, a piece of pipe is required connecting the inlet and outlet of the radiator (bypass). Its diameter is taken a size smaller than that of the riser, and the length is chosen taking into account the distance between the heating pipes. With a bypass, it is possible to prevent underpressure zones in the system.
It is allowed to install pressure and temperature sensors in the battery piping as control equipment. To prevent the formation of blockages, a coarse mesh filter is mounted in it. It is placed on the supply pipe - in the area in front of the thermostat.
Disconnecting the heating riser
Before replacing a riser from old pipes, you will have to disconnect it from the heat supply, which is associated with organizational and technical difficulties. To resolve this issue, the following preparatory procedures will be required:
- filing an application with the Criminal Code responsible for supplying heat to a residential building;
- agreement with her representative on the timing of the replacement;
- discussion of the issue with neighbors at the entrance, who are directly concerned with disconnecting the riser from the heat supply.
The last point is the most difficult to implement, which once again confirms the validity of work in the summer. In this case, the coolant in the riser is partially or completely absent, and the ongoing repair does not affect the neighboring apartments in any way.
In any case, before updating the distribution system, you will have to do the following:
- receive technical specifications from the heat supply company with the parameters of the system components and the piping diagram specified in them;
- purchase all the necessary equipment, including pipe billets and batteries;
- agree on the time of disconnection of the heat supply with the cooperative or the council of residents.
The riser is renewed independently or professional workers are invited for this. The second option is more preferable when heating batteries are transferred simultaneously with the replacement. If the volume of work is not too large, it is more convenient to negotiate with a local plumber. For a reasonable fee, he will carry out all the preparatory operations, allowing you to immediately start installation work.
It is enough for the owner of the apartment to agree on the time of their holding and invite a plumber just before the start of the dismantling of the old riser. Tom will need to go down to the basement of the building and close the required valve. After disconnecting the riser from the heat supply system, it will also help to dump the water mass remaining in the pipes.
It is imperative to drain the water from the vertical pipes beforehand, since even after disconnecting from the substation, a small amount of it remains in the pipes. The height of the accumulated water column often reaches the uppermost floors of city buildings.
