Smart wire to protect the pipeline from freezing. How to protect pipes from freezing

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Relatively warm winters previous years and the constant chatter of Greenpeace about global warming somewhat relaxed summer residents-builders when installing communications in terms of protection from the cold. And the current rather severe winter has shown many who is who and how to do them. In particular, this year the topic on various forums was “Help! The water supply system froze much more than in other years.

As you know, it is much easier and cheaper to prevent a disease and a problem than to treat it later. Therefore, those whose water supply system periodically freezes in winter and those who are just planning to lay a water supply system for year-round use should take care in advance of installing an insulated water supply system. Especially if the well or borehole is located quite far from the house.

The basic principle when installing a water supply system designed for year-round use is to lay the water supply pipe below the maximum possible freezing depth. As you know, the temperature in the depths of the soil is always approximately the same and ranges from +4 to +6 degrees. However, this can be very difficult, since the freezing depth can reach one and a half to two meters. The construction of such a deep trench of great length requires very large amounts of labor. earthworks and is not even always physically possible. Let's look at a few alternative options devices for non-freezing water supply without laying pipes at great depths.

Option with constantly circulating water.

Many summer residents who do not have a permanent winter water supply, or who installed it incorrectly, solve the problem with freezing in the following way. Open the faucet in a sink so that water constantly flows but in a thin stream. The method is simple, but not always applicable. Especially if the sewage system is not central, but the drain goes into a sealed septic tank. No matter how thin the stream of water is, the daily discharge reaches several hundred liters. And this clean water, as a rule, already cleaned with some filters. Pointless water purification and pointless discharge into a septic tank, which also needs to be removed. Pointless operation of the pumping station or pumps. In addition, quite often people simply automatically turn off the tap or forget to open it when leaving. And when returning to the house they find a frozen water supply.

But you can organize the circulation of water without draining it into the sewer. To do this, when installing a water supply system, it is necessary to lay not one, but two pipes. (generally speaking, this is a good thing to do anyway). Then the second pipe is used as a return pipe, and the pump, pumping water out of the well, drains the same water into it. In order not to constantly run the pump, it can be turned on using a timer. For example, for 1-2 minutes every 20-30 minutes. During this time, the water in the pipes will not have time to freeze.

Generally speaking, when 1 liter of water freezes, about 330 kJ of heat is released (or about 90 W*hours). Average heat loss per 1 linear meter pipes in the ground are considered to be about 10-15 watts. Knowing the diameter of the pipe (and therefore the volume of water in it), it is not difficult to calculate the required frequency of switching on and the duration of operation of the pump for a complete change of water in the water supply system, that is, for replacing cooled water with new water at the temperature of the groundwater.

Option for removing water from the water supply.

What is not there cannot freeze. Therefore, to prevent water from freezing in the pipe, water is simply removed from it. This method is well known to those who use submersible pumps located directly in the well. They just need to make a small hole in the hose (2-3 mm) not far from the pump, and immediately after turning it off, all the water from the water supply flows back into the well. A check valve is placed at the other end of the pipe, which allows air to fill the pipe as water drains. And when the pump is turned on, the valve closes and water enters the water supply system.

However, this method is very labor-intensive for those who have suction pumps, i.e. located directly in the basement or house. For their normal operation a constant presence of water in the suction pipe is necessary. For this purpose, they even have a check valve at the inlet end of the pipe that prevents water from flowing into the well. This means they will have to constantly fill it from some container. In principle, this is not a difficult procedure for those who visit their home on short visits. The process of bringing the system into working condition will take only a few minutes. But you will need to remember to drain the water from the water supply when leaving. It will be more convenient for them

Option with creation high pressure in the water supply.

As you know, water under pressure does not freeze. You see water pumps on the streets of villages and villages. They don't freeze in cold weather. The pipes are laid quite deep. But the speakers themselves are “outdoors”. And the water flows from them regularly in any frost and does not freeze. And all because in the pipe it is under pressure of several atmospheres.

If you install a small receiver into the water supply and pump pressure into it to 3-5 atmospheres before leaving, the water in the pipe will not freeze. To bring the system into working condition, this pressure must be released and it is ready for operation. Of course, this is also an “intermediate” method, the water supply is not always ready, and requires pipes that can withstand such pressure, but as an option... The easiest way to implement it is again with submersible pumps. They develop the required pressure of 5-7 atmospheres. And it is enough to install a check valve immediately after the pump, close the tap in front of the receiver, and turn on the pump, and the entire pipeline from the well to the receiver will be under pressure. Of course, the pipeline must be designed for it.

Option with pipe heating by cable.

This option in Lately is becoming increasingly widespread. The idea here is quite simple. Winter, no matter how harsh it may be, is not forever, but only a few months a year. Therefore, the likelihood of water supply freezing exists only during this period. Therefore, there is no point in digging 2 meters deep, but 50 cm is enough, insulate the water pipe and wind a heating cable on it. Or rather, first wind it and then insulate it.

The idea is very sound and workable. A branded heating cable will cost approximately 400-500 rubles per linear meter. Its distributed power should be within 10-20 W per linear meter. However, it is also possible to use a homemade heating cable made from ordinary wire. One of the readers of this site conducted very successful experiments with its use (see the article Homemade heating cable for water supply). I would like to note that such a heating cable is low-voltage (unlike branded ones), which means it is safe and can be used not only outside, but also inside the pipe. Those. arrange heating of existing water pipelines without excavation. The most frozen place in the water supply is usually the place where it enters the house. Therefore, a few meters of cable inserted into the water pipe can possibly solve this problem.

Option with pipe heating by air.

Here I would like to digress a little towards the construction of water pipelines in general. Let me remind you that in winter the ground begins to freeze from top to bottom... That is. There is constant heat from below (+5 degrees), and cold from above. Heat spreads in winter from bottom to top. When installing a water supply system, they usually try to insulate the pipe. Moreover, from all sides, putting pipe-shaped thermal insulation on it. Thereby insulating it not only from the cold from above, but also from the heat from below. But due to this heat “from below” it could be heated. That's why correct device The plumbing should obviously look like this:

In this case, we kind of create an umbrella from the cold from above. At the same time, heat from below passes to the pipe unhindered and heats it.

To others important point is not just laying a water pipe, but laying a pipe within a pipe. Polypropylene sewer pipes of 110 m are inexpensive, and stretching a water pipe through them opens up very tempting prospects.

Firstly, we get the opportunity to quickly pull an emergency hose through this collector in case of any unforeseen circumstances. To do this, it is enough to lay a wire or cable in the pipe. Or replacing a water pipe without excavation.

Secondly, it becomes possible to guarantee pipe heating under any circumstances. After all, cables can also sometimes deteriorate, burn out or short out. All you have to do right away is start pumping warm air into the collector pipe and you can thaw the frozen water supply.

Thirdly, it becomes possible to arrange heating of the water supply using the heat of the earth. If you have a basement or cellar with running water, then the temperature there is probably always positive. If you install an exhaust pipe at the other end of the pipeline and equip it with a suction deflector (for example, the Volpert-Grigorovich type), then warm air will slowly but constantly be drawn from the basement into the pipeline collector and heat it. This way we will get both free and very reliable heating of the water supply and ventilation of the basement. The costs of installing such a collector are not significant.

In winter, pipes need protection from freezing. The problem is most relevant for owners of country and private houses. They need to establish timely supply of hot and cold water to the house, taking into account seasonal conditions. The right system heating pipes will preserve the integrity of water tanks and pipelines for many years.

It is a mistake to think that good thermal insulation- this is sufficient protection for pipes. Already at a temperature of -10 ° C, a pipeline with a diameter of 3/4 inch, wrapped thermal insulation material 25 mm thick, will freeze within 13 hours.
If the pipe freezes completely, it will burst. In this case, the water supply will stop, and flooding will occur at the rupture site. In addition to the disrupted water supply, the owner of the flooded area will also suffer large material losses.

These troubles can be prevented by using a ready-made kit for heating pipes or using a self-regulating heating cable.
The set is a piece of self-regulating cable of a certain length, equipped at the factory with a so-called cold lead cable with electrical plug. The cable is designed to protect domestic water supply systems using pipes with a diameter of up to 32 mm from freezing; it is completely ready for use immediately after fixing it to the pipe and installing thermal insulation on top of it.
We also offer (Denmark) and (Germany)

Most often used for heating pipesself-regulating heating cable.
A self-regulating cable produces an amount of heat depending on the temperature of the pipeline: the lower the temperature in the pipeline, the more the cable heats up. Conversely, if the pipe heats up more, the cable reduces the level of heat generation. Self-regulating heating cables, unlike constant power cables, do not burn out or overheat.
They are much more reliable in operation than resistive ones and are designed for a long wear life. In addition, the use of self-regulating cables will significantly reduce energy costs.

Well or well country house, as a rule, is located a few meters from the house. Sometimes, a well is made in the underground or basement of a house, but even then measures against freezing of the pipeline will not be superfluous. As a rule, water in a pipe freezes not in the underground section of the pipeline, but at the “ground-air” boundary, then crystallization occurs along the air section of the pipe. Another “weak” section of the pipeline is located at the “underground-house” border due to the inevitable draft along the pipe contour in this place, which is quite difficult to get rid of.

I would conditionally divide all measures to combat pipe freezing into passive And active. It is advisable to provide for both of them in advance, at the design stage. So:

Passive measures.

The material of the supply pipe itself must be heat-insulating. It could be polyethylene, polypropylene, metal-plastic. Metal pipes are undesirable.
It is advisable to choose a larger diameter of the supply pipe. The larger the diameter of the pipe, the greater the volume of water contained in it, the thicker the pipe wall (additional thermal insulation), the longer it will take for the water to cool to freezing temperature. Optimal diameters are from 3/4 (20mm) for polypropylene and metal-plastic (preferably 26mm) to 1½ (40mm) for polyethylene (more is possible, but it is expensive).
The depth of the trench for the pipe should be comparable to the average freezing depth of your area, from 0.7m to 1.5m.
The pipe must have a slope towards the well or borehole.
The pipe must be insulated.

I conventionally call the following measures

Active:

It is necessary to provide easily detachable pipe connections at the exit from the well (well) and at the entrance to the house or basement, for possible inspection of the mouth of the underground section of the pipe and
The best active protection is to run the heating cable through the supply pipe. It is not necessary to buy an expensive self-regulating two-wire one. In the worst case, you will only use it a few times during the winter. A cheap single-core cable for heated floors is quite enough domestic production. The only limitation in its use is that its activation time should not exceed 15 minutes. If this was not enough, simply repeat the procedure after 10-15 minutes so that the cable cools down a little. It makes no sense to turn on the cable for constant heating (this requires another cable), this unnecessary waste energy, and the cable may overheat. The cable is attached to the pipe using plastic clamps or tape.
When using submersible pumps, you can make a small hole in the pipe (1-3mm) 3-5cm from the pump for direct current water. Flowing water will never freeze. Unfortunately, when using pumping stations it is impossible to do this.
In severe frosts, if you are at home, spill, i.e. turn on the water at least once every two hours. Then you will only need to warm the pipe and turn on the heating cable once a day - in the morning.

As practice shows, compliance only with passive measures against freezing of pipelines guarantees their trouble-free operation down to 20-25 degrees below zero. Subject to all measures - in any frost.

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Reviews (32) on “To prevent the pipe from freezing.”

Hello! there is a question:
To supply water to the house there is a submersible water pump and a hydraulic accumulator in a closed shaft on the street. I would like to make a pipe from the shaft to the street for use in the yard. How to make sure that the pipe from the HA to the outdoor faucet does not freeze in winter?

Hello, Ivan.
Alas, there is no way to do this. But there is a standard way out for such a situation.
On the “street” pipe you need to install two (!) taps and drainage (a drain with a tap). The scheme is as follows...
The first (main) tap is placed in the shaft, where the water is guaranteed not to freeze. Immediately after it, a tee with a drain valve and a discharge pipe (drainage) is installed. And another crane (working) is placed in the yard, in a convenient place for use. Important condition: the “street” pipe must have a constant slope from the worker to the main valve for normal and complete drainage of water from it.
How to use?
Summer mode. The main valve is open, the service valve and drain are closed. Water cannot freeze, so we only use a working tap when necessary.
Winter mode. The main valve is closed, the service valve and drain must be open (it is very important!!!).
If you need water in the yard, then close the working tap and drainage, open the main one, then open the working tap and use the water. After use, close the main drain, open the drain and the working valve, draining the water from the pipe. We leave the working tap and drainage open. .
Thus, there will simply be nothing in the pipe to freeze; in cold weather it will remain “dry”. But it is very important to leave the working tap open. This is even more important than open drainage. Failure to comply with this condition will lead to breakdown (rupture) of the working valve.

With the arrival of winter, the operation of the pipeline becomes significantly more difficult due to ice jams that appear under the influence of frost. Frozen water narrows the passage opening and can cause pipe damage. Therefore, in winter it is necessary to protect pipes from freezing as reliably as possible.

Organization of water circulation

Water is less likely to freeze if it is constantly circulating through the pipes. This can be achieved using the “open tap” method. But this is irrational in the absence of a central sewerage system, if water is supplied using a pump. In this case, it is better to organize closed system pipeline by installing a second pipe and a three-way valve. The liquid will circulate and drain back into the well. Set a timer to turn on the pump to reduce electricity consumption.

If water is supplied from a centralized water supply, it is better to drain in small portions. Use a storage tank to store water.

Cable heating

You can protect your water supply from freezing using an electrical cable. He has waterproofing coating, so it can be installed both on top of the pipe and inside. To determine the required cable power, you need to take into account the type and diameter of the pipe, its location, length, and the presence of thermal insulation. The longer the pipe and the thinner the layer of thermal insulation protection, the more powerful the cable should be.

The wire for installation inside has a special coating, which allows use in pipelines with drinking water. It is connected via a standard tee. If the cable is installed outside, it is attached to the pipe using aluminum tape, and insulation is put on top to avoid heat loss. It is better to use a thermostat complete with a cable to save electricity.

Video: heating cable for pipes

Thermal insulation materials

Additionally, you can protect pipes from freezing using materials that have low thermal conductivity and high resistance to external factors:

Glass wool. This is a variety mineral wool with a fibrous structure, for the production of which the same raw materials are used as for the production of glass. Due to its low density, the material crumbles, so it must be additionally insulated with fiberglass or roofing felt.
Styrofoam. The material is obtained by foaming polystyrene granules. Produced in the form of a cover of 2 halves in a longitudinal section. It is characterized by low strength, so it needs additional protection.
Basalt insulation. Made from basalt fiber in the shape of cylinders. Requires a protective layer, which can be foil insulation or roofing felt.
Foamed rubber. Elastic, waterproof material can provide heat savings of up to 70%. Available in the form of tubes or sheets.

Application of warm air

In winter, the ground freezes from top to bottom. Thus, heat spreads from below. In most cases, pipes are insulated along the entire perimeter. Thermal insulation occurs not only from cold air from above, but also from heat from below. Therefore, it is better to protect the pipe from the cold with a layer of heat-insulating material only on top. It will be provided by heat coming from the ground.

Can water pipe lay inside polypropylene pipe larger diameter. Warm air will be pumped into the collector from a heated room or basement.

To avoid freezing of pipes, it is better to take this possibility into account even at the stage of organizing water supply and ensure reliable thermal insulation.

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