What is this unusual device for? Bypass for heating: what is it, installation of the device. Bypass assignment for heating

A professional approach to creating a heating scheme is distinguished not only by accurate calculations, but also by the use of all means to improve the system. To do this, the individual characteristics of the building, the climatic characteristics of the region and, of course, the level of service comfort are taken into account. An important function in the overall scheme is performed by the bypass in the heating system: the purpose, calculation, diameter of this element is mandatory not only when creating a new main, but also when modernizing an old one.

Purpose of bypass in a heating system

Why is a bypass needed in a heating system, and what functions should it perform? Its general purpose is to form a parallel flow bypassing heating components (radiators, shut-off valves, circulation pumps). It is a highway connecting the conditional input and output pipes of a specific system element.

It can perform several functions. For example, a bypass in the heating system of a multi-story building is necessary for repair or maintenance work. This especially applies to replacing radiators during the heating season. With its help, you can redirect the coolant flow bypassing the battery.

In addition, the parallel transport highway performs the following functions:

• Adjusting the coolant flow into the radiator. By installing the appropriate component (thermal head), you can automatically reduce (increase) the volume of hot water in the battery;
• Scheme modernization- another purpose of the bypass in the heating system. First of all, this applies to single-pipe circuits, in which without this element it is impossible to change the level of water flow in the radiator;
• Creation of universal heating. When the electricity is turned off, the blades of the circulation pump will make the gravitational movement of liquid in the pipes almost impossible. But why do you need a bypass in the heating system in this case? With its help, a bypass channel is created in which hydraulic resistance will not interfere with the natural circulation of water.

At first glance, installing an additional channel requires only a pipe of the correct shape. But without the right components, it will not function properly. To do this, it is necessary to correctly calculate the diameter of the bypass in the heating system and install shut-off valves. With its help, you can redirect the flow of liquid bypassing a certain component of the system or eliminate the movement of water through the bypass.

When installing a plastic pipe as a bypass into a steel main, you need to take into account the degree of its thermal expansion.

Bypass installation

Knowing how the bypass works in a heating system and why it is needed, you can move on to specific examples. Most often it can be found in single-pipe schemes of multi-storey buildings. But besides this, it is widely used in autonomous systems of private houses. For proper installation, it is necessary to calculate the heating bypass and select components for it.

Bypass in the radiator trim

The organization of a bypass channel in the radiator piping is done not only in one-pipe, but also in two-pipe schemes. With its help, you can regulate the flow of coolant and perform repair and maintenance work without stopping the boiler or disconnecting from the central heating.

How to make a bypass to the heating system yourself? First, you should make preliminary calculations and select the right components. It is recommended to use pipes made of the same material as for the entire line. The difference will only be in the cross section. Without fail, the diameter of the bypass in the heating system must be 1 size smaller than the cross-section of the main pipe.

Before installing it yourself, please read the following recommendations:

• Ball valves must be installed as shut-off (shut-off) valves. With their help, you can quickly redirect the coolant to the bypass;
• Installation of a mixing valve is not rational. It effectively mixes cold and hot water in collector systems, where the coolant flow rate is initially normalized. For pipelines, and even more so for central heating, this is impossible to achieve;
• The installation of a bypass in a one-pipe heating system is mandatory. It is important to pre-coordinate the installation with the management company.

To install a parallel pipeline, consumables are purchased. Let's consider, using the example of a metal-plastic highway, the optimal set of components. Why is a bypass needed in the heating system in this case? It will act as a bypass circuit to repair or replace the radiator, as well as to regulate the flow of water into the battery section. First, the distance between the forward and return radiator pipes is measured. Before making a bypass into the heating system, the pipe is cut to the dimensions obtained. The most common pipe size in autonomous heating is ½. Based on this, components will be selected, the characteristics and costs of which are presented in the table.

Before the bypass in the heating system starts working, you should check the reliability of all connections. To do this, pressure testing of this section of the pipeline is performed, preferably hydraulically. Only after this can the pipes be filled with coolant.

To install a bypass in the heating system of a multi-storey building, you must first shut off the riser to which the radiator is connected. Only representatives of the management company can do this.

Bypass for installing a circulation pump

Unlike radiator piping, the purpose of a bypass in a forced-type heating system is to minimize hydraulic losses. To do this, the pump is not installed on the return pipe, but directly on the bypass.

What is a bypass in the heating system in this case? It performs the same functions as when piping the radiator. A distinctive feature is the installation of a check valve on the pipe. It is necessary to prevent a change in the direction of coolant flow when the pump is turned off.

In addition, during installation you need to take into account the following features:

• A bypass is required in an autonomous heating system with forced circulation. Without it, when there is a power outage, the speed of movement of the coolant will sharply decrease;
• The optimal diameter of the bypass in the heating system for piping the pump is 2 sizes smaller than the cross-section of the main pipe;
• A strainer is installed in front of the pump to prevent debris from entering its mechanism.

It is advisable to use ball valves as shut-off valves. This circuit node does not require smooth adjustment of the coolant volume. Most often, it is necessary to quickly shut off its flow to replace or repair equipment.

The pump in the heating bypass is calculated not according to the cross-section of the bypass pipe, but according to the diameter of the main line.

Bypass in the central heating system

The purpose of a bypass in a single-pipe heating system of a multi-storey building is the ability to carry out repair work on the radiator without disconnecting the central riser. To do this, the valves are closed and the battery is actually disconnected from the general system without stopping the coolant in the main.

The principle of installing a bypass in a single-pipe heating circuit is almost completely identical to that for the described autonomous one. The difference lies in the operating features of centralized systems, namely:

• If there is no bypass highway, it can only be installed with the permission of the management company;
• When choosing materials and components, you need to take into account possible water hammer, typical for central heating;
• Installing a thermostat will reduce the heat transfer of the battery in case of increased room temperature. Alas, the reverse process is impossible - operating a bypass in the heating system can only reduce the flow of coolant, but not increase it.

If there is a possibility of a low level of coolant in the batteries, you need to install a shut-off valve on the bypass. Thus, the entire flow of hot water can be redirected along the circuit with the radiator.

If you make a bypass in a central heating system without a ball valve and thermostat, the volume of coolant flow into the battery will decrease by 20-30%.

To reduce the labor intensity of the work, it is recommended to purchase ready-made bypass units. But before that, you need to make all the calculations for installing a bypass in the heating system - the optimal diameter, set of components, etc. If there are no ready-made structures with the necessary parameters, you can make it yourself. The best option is to make a bypass into the heating system from metal-plastic.

The video material clearly shows the functional features of the bypass in the heating system:

Bypass- this is a piece of pipe identical to a section of the main line, installed in its key places. It is installed only in single-pipe circuits that provide flow through only one pipeline, which originates from the boiler and ends near it. At the same time, the water first leaves the heat generator in the direction of all the radiators of the house, and then, having given up its heat to them, returns to it.

The main difference between two-pipe systems and their single-circuit counterparts is the ability to separate the coolant supplied and returned to the boiler into separate flows. Therefore, for a two-pipe system there is no need to install a bypass. And in the case of one circuit, when both the supply and return are inseparable and flow in one stream, it is simply necessary.

This bypass structure is mounted on contours from one pipe, which can run in 2 planes: vertical and horizontal. This means that the bypass can be installed in different ways. Vertical contours are found in buildings with a height of 2 or more floors, horizontal contours are found in private one-story buildings and apartments.

Depending on the functions assigned to such a bypass structure, the location of its installation is selected: on a pump that drives the coolant through a pipe or on separate radiators.

Regardless of the installation location, the bypass element ensures continuity of fluid flow in the pipeline regardless of the serviceability of the main units. In a heating circuit, the bypass is a spare channel through which the liquid continues to circulate in the circuit, which means that pressure drops and surges will not occur in it.

Bypass diameter

Depending on the installation location of the device - on the battery or pump, the required circuit diameter may vary.

A bypass of smaller or identical diameter to the main pipe is mounted on the pump. There is no fundamental difference between these options, since its main task is simply to maintain coolant circulation in emergency situations, at least by gravity, for example, when a pump operating from the network does not receive power due to temporary power outages.

In this case, it is impossible to narrow the circuit itself, and the diameter of the pipes leaving the pipeline does not play a major role. When the pump stops operating, the flow of coolant through it will completely stop, and therefore, with identical sections of its pipe to the main, the bypass element will not change the direction of water flow. And if it is necessary to flow water through the pump, it is enough to simply block the movement of the coolant using a ball valve on the main pipeline.

But when installing a bypass directly on batteries, its diameter plays a major role, since it must be optimally combined with other equipment. Firstly, compared to the pipes connecting the radiators to the main line, the bypass should be 1 size smaller in diameter. Secondly, the bends to the heating radiators themselves require an order of magnitude smaller caliber than the main pipe.

Thus, work is ensured according to the following scheme:

1. Coolant flows along the circuit to the place where radiators are installed on it.
2. Meeting along the way branching between the direct flow into the radiator and the bypass route through the bypass, the water will flow along the route that currently has the least resistance.
3. Some water will flow, overcoming resistance without changing its original vector of movement.

If the diameters of the outlet pipes coincide with the diameter of the bypass, a sufficient amount of water will not enter the radiators and their thermal efficiency will decrease. And if the diameter of the bypass exceeds that of the pipes, the coolant flow will stop completely.

Diagram of pipe sizes in a system with a bypass on the radiator:

Reducing the diameter of the pipes relative to the main pipe provides additional acceleration of the coolant flow, which causes it to move more intensely in the radiator itself, releasing thermal energy more evenly and efficiently.

For example, in a polypropylene heating system, the diameter of the main pipeline is 32 mm, which means that pipes are needed that distribute water to radiators with a diameter of 25 mm. A 20 mm diameter loop is suitable for such a system. It will be able to ensure water flow along the optimal route with the least loss of thermal energy.

Application

If there is a pump in the heating circuit, it is installed directly on the bypass part. This is a common practice when an electric pump is installed in a gravity circuit - a single pipeline in which the coolant circulates by gravity.

It accelerates the speed of water flow through the pipes and thereby increases the efficiency of the entire heating system. This is due to the fact that due to the high flow rate of the coolant, it manages to pass through the entire circuit without losing most of the thermal energy.

In practice, this is expressed in the fact that the last radiator of the circuit receives not cold or barely warm water, but rather hot water, which still has a sufficient amount of thermal energy to ensure heating of the room in which it is installed.

Installation

bypass in a one-pipe system

bypass on the mains pump line

There are 2 options for installing a bypass together with a pump that circulates water in a single pipeline: on a new or old circuit. There is no difference between them either during installation or during heating operation.

When installing a bypass together with a pump, the following rules must be observed:

1. Firstly, on the main circuit in the middle of the bypass pipes, it is imperative to install elements blocking the pipe. This will allow the coolant to flow through the bypass with the pump, without the effect of reverse flow.
2. Secondly, it is extremely important to correctly place the pump on the bypass structure: the impeller axis must be located in a horizontal position, and the cover with the marks must be directed upward. If there are inconsistencies, the cover can be twisted by unscrewing the four fasteners on the pump body. This positioning of the marks solves 2 problems: it makes it easier to access them for connection and, in the event of a leak, it reduces the likelihood of liquid getting on them.
3. Third, only a ball valve should be installed as a lock, and not a check valve.

Because with the valve the circuit will begin to function like this:

1. Working pump accelerates the flow of water in the circuit.
2. Coolant through the bypass flows into the main pipeline in opposite directions.
3. By effective vector it goes without restrictions, but in the opposite direction it is delayed.
4. It automatically overlaps and does not allow water to circulate normally through the two pipes.

Thus, increased coolant pressure is created on the valve plate precisely after the pump, because the flow rate behind it is always faster. In theory, when the pump is turned off, the coolant no longer acts on the valve, which in this case does not close.

This allows the liquid to move by gravity through the main pipeline without getting into the bypass. But in reality, the bypass with the valve does not function as it should.

The problem is that the valve disc generates excessive resistance comparable to a whole meter of pipe. Under the conditions of the gravitational circuit, water will not be able to overcome it, and its circulation will stop completely.

Before installing a bypass in combination with a check valve, you need to know that there is actually no advantage to mounting the pump on it.

If the valve is replaced with a standard ball valve, it becomes possible to direct the vector of water flow in the circuit.

bypass with pump

In order to install a bypass with a pump in the heating circuit, you will need the following set of parts:

• welded-in line pipes with threads;
• ball valves mounted on both sides;
• corners;
• pre-filter installed in front of the pump;
• a couple of American women to dismantle the pump for maintenance and repair.
• Installation in front of the radiator. What does it matter? Installation rules: how to install.

A bypass element is installed in front of the radiator in case water stops circulating inside it for some reason, then its circulation along the bypass throughout the rest of the circuit will continue, despite the malfunction of one of the elements.

It performs the following functions:

1. Provides continuous movement of coolant along the main heating line.
2. Allows p regulate the water temperature in the radiators.

In heating systems with one main circuit, water circulates in it, sequentially transferring heat to 1, 2 and subsequent radiators. Thus, as it passes through each subsequent radiator, the thermal energy of the water decreases, which means that the first heating element will heat up much better than the last.

Installing a bypass in heating allows you to mix the hot coolant that comes directly from the main line with less energy loss with the one that enters the radiators and loses it, which allows you to partially compensate for these losses right on the go, without waiting for it to return directly to the heat generator.

Bypass device:

Installation rules:

1. Vertical installation provides for connecting the radiator to the riser using a pair of pipes. The bypass closes them together and is mounted in front of the battery.
2. Between the main pipeline and the bypass element there is no need to install any constipations; this eliminates both human error and the possibility of stopping circulation in the event of a malfunction.
3. In a horizontal one-pipe system the circuit is fixed in a horizontal plane directly in front of the battery. And to ensure circulation, it is necessary to select its optimal diameter in relation to the main line and pipes.

1. Bypass installation desirable in conditions of insufficient natural circulation of fluid in the heating circuit.
2. Constructing a bypass yourself, it is not necessary to select each of its elements separately; it is better to purchase a ready-made assembly at a specialized store, which will save time and guarantee against inconsistencies between elements during the assembly process.
3. For automatic regulation temperature in the home, can be used with a built-in ball valve.
4. Horizontal installation of the device preferable due to the lower likelihood of air accumulation in it.
5. When installing the device it is necessary to provide in advance additional support points and clamps that will not allow it to move under the influence of gravity or other factors.
6. In case of poor water quality with a large number of impurities and suspensions, to increase service life, you should choose special pumps with filters, which are recommended to be periodically removed and cleaned.

Any water heating system, regardless of its type, must be designed and installed in strict accordance with existing rules, taking into account all the features of the building and the placement of heat exchange devices (radiators) in it. When assembled and debugged, it should work like a balanced overall mechanism. There are no trifles in this matter - each element of the system performs one or another function, and ignoring the installation of any parts or components may result in inoperability or extreme inefficiency of the functioning of the entire heating system as a whole.

This publication will discuss the bypass in the heating system, what it is, in what cases it is used, what role it plays and other related issues. Even if the owners do not intend to install their system themselves, the information will still be useful to them. Firstly, it helps to understand the requirements for the proper operation of heating devices - there are certain nuances here. In addition, this will give them the opportunity to “speak the same language” with invited specialists. If the plumber who comes does not know anything about the bypass, then this is an obvious “impostor”. The other extreme is that, taking advantage of the inexperience of the owners, the specialist begins to charge an unrealistic price for installing a “complex bypass unit.” So it’s better to have an idea of ​​the subject of the conversation in advance.

What is any bypass in principle?

An inexperienced user may get the first impression that behind the name “bypass” lies some kind of device that is complex in its structure, installation and principle of operation, which is simply impossible to get into trouble without the appropriate training. In fact, everything is much simpler. Surely everyone has seen this same bypass with their own eyes, they just didn’t realize that it was called that.

The clue is already in the name itself. Try to enter the word “bypass” into any of the online translators, and you will immediately get a bunch of options united by one meaning - “bypass”, “detour”, “detour”, “circumvent”, “go around” and so on.

In plumbing practice, a bypass is usually called a jumper pipe embedded in bypassing a particular device. It creates the possibility of an alternative direction of fluid flow (ordinary water in plumbing systems or coolant in heating systems). The bypass can operate in an uncontrolled mode, that is, be constantly open, have valves or other devices that automatically switch the flow of liquid as needed, or be controlled manually using taps or valves installed on it.

In heating systems, bypasses can be installed in various areas. Most often this is piping heating radiators. In autonomous systems of private houses, it finds traditional application in the circulation pump assembly. In complex-structured collector-type heating systems, the bypass becomes an integral part of the mixing unit. And finally, it is also used when piping solid fuel boilers. Let's look at each of these cases in more detail.

Prices for bypasses for heating systems

bypass for heating radiators

Bypass in the heating radiator piping

The need for a bypass on the radiator, its principle of operation

To imagine the importance of the bypass, let's remember how the heating system is usually organized in apartment buildings.

In old high-rise buildings, in order to simplify the design and reduce the cost of installation, a single-pipe heating system was and remains to this day widely used. In the heating station (at the elevator unit) of the building there are two collectors - supply and return. A riser pipe goes up from the supply manifold, and from it, starting from the top floor, heating radiators are successively “strung” (option A. – with top feed) Another similar scheme (option b. – with bottom feed), when on the way to the top point the riser also captures radiators located in series.

Try to imagine what will happen if at least one of the radiators, no matter in which riser and on which floor, suddenly has an accident. To replace the battery you will have to remove it. And this automatically entails the need to break this very consistent “chain”. The entire riser (or even two, as in the example on the right) becomes completely inoperable.

And now - the same circuit, but supplemented with bypasses on each of the heat exchange devices.

Obviously, if an accident occurs on any of the batteries, or during the heating season it becomes necessary to shut off any radiator, for example, to replace it with a new model, this will not affect the overall performance of the system. It is enough to shut off the heat exchange device using shut-off valves (and their installation is highly recommended), as shown in the callout on the right, and it is quite possible to carry out repair work or complete dismantling. The bypass will ensure the necessary circulation of coolant through all other radiators in the riser.

This is not the only advantage of a bypass in the radiator piping of a single-pipe heating system. Many people are probably familiar with the situation when warming suddenly comes in winter, but the centralized heating system is not so flexible as to instantly respond to such changes. As a result, the rooms become unbearably hot, which can be even worse than a slight lack of heat. Wide open windows in winter are drafts that do not bring anything good. This means that it is desirable to be able to adjust the heating level of the radiators.

A single-pipe system with bypass provides this opportunity. It is enough to install a direct thermostatic valve at the entrance to the battery instead of a shut-off valve (or even in series with it), and carry out quantitative adjustment of the heating level as necessary. It consists in changing the volume of coolant passing through the radiator per unit of time. The coolant that is not required to achieve the set heating level is simply “discharged” further into the general circulation system through the bypass.

It would seem, what prevents you from installing a similar thermostatic tap or valve without a bypass? Yes, indeed, there will be thermoregulation, but since the operation of such a faucet is based on narrowing the passage and, accordingly, reducing the total volume of coolant flowing through the radiator, this will affect absolutely all batteries connected to this riser. And the neighbors are unlikely to like it.

In a word, in a single-pipe heating system of an apartment building, the bypass becomes a mandatory element of the radiator piping.

In autonomous systems of private houses, owners are, of course, free to “experiment” as they like. And yet, installing a bypass gives them a lot of advantages - a more uniform distribution of heat throughout the rooms, and the already mentioned maintainability of any part of the system. If desired or necessary, it is always possible to even completely turn off a particular room - this will not affect the overall performance of the heating.

In a private house with two or more floors, exactly the same riser system can be used, or horizontal wiring for each level, as in a one-story building. The essence does not change - a jumper is still mounted between the inlet and outlet of each radiator and with horizontal wiring of a single-pipe system.

One of the “classic” systems, combining simplicity and cost-effectiveness of installation and sufficient flexibility in adjustments, is “Leningradka”. Already in its very design are the principles of a “bypass unit” on each heating radiator. Moreover, very often the role of such a jumper between the inlet and outlet of the radiator is performed directly by the horizontal pipe of the heating circuit itself.

Due to its simplicity and a number of undeniable advantages, the Leningradka system remains one of the most popular among private developers.

How to properly organize the Leningradka heating system?

The principle diagram of such a system is the same, but various options are also possible in its implementation. Especially for those who want to organize in their home, our portal contains a very detailed publication dedicated to this particular issue.

Video: the key role of bypasses in piping radiators of a single-pipe heating system

Installation of a bypass in a heating radiator piping

Those owners who have already dealt with the installation of plumbing pipes and related fittings should also cope with installing a bypass on a heating radiator. If you have the skill of assembling threaded connections, fitting units, welding (soldering) of polymer pipes, then no special difficulties are foreseen.

• There should be no shut-off elements between the main circuit pipe and the bypass. This eliminates the possibility of even accidentally blocking the normal coolant circulation throughout the entire circuit.

• If the bypass is mounted on a vertical riser, then it should be placed, if possible, at the maximum distance from the riser and at the same time as close to the heating radiator as possible. Of course, in this case, the free space for installing shut-off (and control, if planned) valves at the inlet and outlet of the battery must be thought out in advance.
• The diameter of the pipes from which the radiator bypass assembly is assembled is always important. The “classical” scheme is the following: on the branching tee, the pipe going to the heating radiator has a diameter one size smaller than the diameter of the riser, and the bypass itself is two sizes smaller.

An example is shown in the figure: the circuit (riser) is made of a 1-inch pipe, therefore the radiator connection pipes should be ¾ inches, and the pipe from which the bypass is made should be ½ inches. With such proportions, the correct operation of the radiator will be ensured without any additional intervention - according to the laws of hydraulics, the coolant flow will be divided into the main one, flowing through the radiator and causing it to heat up, and the direct one, going through the bypass. This, by the way, ensures the most optimal consumption of thermal energy. Heat is practically not wasted on the direct section of the bypass, thereby somewhat compensating for the reverse mixing of flows those losses that went into heating the given room.

When the contour is horizontal, the ratios are usually somewhat different. The role of the bypass here is played by the main tube itself. However, it is recommended to narrow the section between the radiator branch tees by one size. Accordingly, the connection pipes for the heating battery with taps must be two sizes smaller than the main pipe.

• Is it permissible to install a valve on the bypass? It would seem that it suggests itself - with its help you can also regulate the amount of coolant passing through the radiator. For example, if there is insufficient heat, such a measure can have a certain effect - by closing the tap, the owners redirect the entire flow through the battery.

The question is ambiguous. If we are talking about the riser of a single-pipe heating system in an apartment building, then installing a tap will be a serious violation. Shutting off the bypasses in one or more apartments leads to an imbalance in the overall heat distribution scheme, that is, the effect of increasing heating in one place is achieved exclusively at the expense of other residents of the house. If complaints are received about the quality of public services, and an inspection reveals unauthorized installation of taps on bypasses, regardless of their closed or open position at the time of the inspection, then there is no doubt that these owners will be held responsible for everything. It is clear that it will be very difficult to make excuses to your neighbors, and this way you can make a lot of enemies. This does not even include possible administrative measures.

But in the autonomous system of a private house, such control valves are installed quite often. In this case, there is no need to strictly observe the proportions of the diameters of the bypass pipes - everything can be balanced manually, narrowing or widening the passage for the coolant using a tap. In Leningrad, for example, this is quite a common occurrence, increasing the overall flexibility of the entire system.

An example is shown in the illustration. In the demonstrated case, radiators are connected to the circuit through conventional ball valves (item 1), which perform only the function of a shut-off valve - for possible complete disconnection of the battery. And precise balancing is already carried out by a needle tap, which is installed on the section of the main pipe between the tees, which acts as a bypass for such a connection. However, this does not prevent us from additionally installing a thermostatic tap or valve directly at the entrance to the battery. In a word, everything is in the hands of the owners.

You might be interested in information on how it is calculated

Installing the bypass does not require many parts. As a rule, if any complex configuration is not needed, everything is limited to two bends, two tees with snowy diameter outlets, two ball valves, several sections of pipes, couplings or bends for final assembly.

Such a unit can be made either from metal pipes or using polypropylene or metal-plastic ones. Below are a few drawings - they are easy to understand for those who know what we are talking about. Well, for those who do not have the skills for such assembly and are afraid to take on independent work, let it serve as a guide for checking the correctness of the work performed by an invited specialist. Among them, unfortunately, there are many obvious inexperienced laymen who want only quick and easy money.

The diagram shows:

Pos. 1 – riser pipe on the coolant supply side. Accordingly, pos. 2 – the same riser, but from the return side.

The transition from the threaded part of the metal pipe to polypropylene is carried out using fittings (item 3).

Pos. 4.1 – two sections of polypropylene pipe (here and in all other areas it is necessary to use reinforced pipe for hot water), with an outer diameter of 32 mm.

Pos. 4.2 – two pieces with an outer diameter of 25 mm.

These sections are welded into two tees (item 5), which may require adapters to the required diameter.

Pos. 6 – the bypass itself, made from a piece of reinforced pipe with an outer diameter of 20 mm.

Pos. 7 – fittings for transition to the metal threaded part of the taps.

Pos. 8 – a thermostatic straight tap (or valve) is placed at the inlet of the radiator. A regular ball valve can also be used if there is no need to regulate the heating level.

Pos. 9 – ball shut-off valve – on the radiator outlet side.

The optimal solution for connecting to a radiator, which allows you to quickly and easily install or dismantle it, is to use a coupling connection with a union nut - “American” (item 10). Very often they are already included in the set of locking and adjustment devices.

Pos. 11 – heating radiator.

The diameters of the pipes may be different - it depends on the parameters of the heating riser. But it is recommended to observe the ratio mentioned in the text above.

The assembly diagram of a piping unit with a bypass using metal-plastic pipes differs only in the use of special press fittings instead of welded ones. Otherwise, the list of parts is very similar. The diagram shows that, if desired, either a shut-off valve or a thermostatic control device can be installed at the radiator inlet.

If the assembly of the unit will be carried out from VGP steel pipes, then everything depends on the skill and preferences of the master. This can be a welded structure, but with a detachable connection on the radiators themselves (slivers or, more conveniently, “American” nuts). It is quite possible to assemble this unit entirely on threaded connections, as, for example, shown in the illustration below:

By the way, in this case you can also purchase a finished part - the bypass itself with already welded upper and lower horizontal pipes. Such assemblies, designed for standard radiator center distances, are sold in specialized stores.

You might be interested in information on how to choose

Another question on the topic of piping radiators - is a bypass needed on a two-pipe heating system?

No, he no longer plays any role there. Each radiator is completely independent, since it “relies” on both the supply and return pipes. Such a parallel connection makes it possible to disconnect or even completely dismantle the blocked battery at any time - this will not affect the overall operation of the entire system.

The two-pipe system is more expensive and difficult to install, but it has many more advantages. It is increasingly being used in multi-storey buildings, and if your apartment has just such a system, then you won’t have to think about a bypass.

True, you need to be absolutely sure that the system is a two-pipe one. The fact is that the presence of a second pipe can be misleading, which only serves as a riser providing an upper supply of coolant, but the system still remains a single-pipe. The radiator is connected in series to one pipe, and in this case a bypass is required.

In a two-pipe system, the radiator is necessarily connected to two different risers - supply and return. The bypass will not play any role in such a situation.

You may be interested in information about what they are

Bypass in the circulation pump assembly

There is probably no need to prove that an autonomous heating system for a private house, operating on the principle of forced circulation of coolant, is more efficient and controllable. Installing a pump quickly pays off both in terms of optimal heat distribution throughout the premises and in economical operation, and this even despite the fact that the pump itself is a consumer of energy. Even those owners whose systems were once assembled were designed for natural, gravitational circulation, now do not refuse the additional installation of a pumping unit.

But here’s the problem: in a number of areas, power outages are not an unusual occurrence. Well, the heating system, tied to a circulation pump, willy-nilly becomes energy-dependent. It’s good if the issue of some alternative power supply for this case is thought out - from an uninterruptible power supply or your own generator. , although this will only help for a short period. This means that it is necessary to plan the heating system so that in such extreme situations it can switch to operation on the principle of natural circulation. And the bypass installed on the pump unit helps with this.

Such a unit can operate in manual mode - in the absence of power, the owners only need to switch the taps, redirecting the coolant flow not through the bypass with the pump, but directly through the main pipe. In other assemblies, valve devices are used - there the flow will be redirected automatically. Another option is an injection circuit, without a tap or valve, but, to be honest, it is not particularly praised, and it is still advised to turn to the “classics”.

In this publication we will not dwell on the pumping unit with a bypass. Not at all because this issue is not important. Rather, on the contrary, a separate publication is devoted to the problems of choosing and correctly installing a circulation pump, from carrying out the necessary calculations to step-by-step instructions for self-installation.

Heating system circulation pump.

The advantages of forced circulation of coolant through the heating circuit are obvious. The pump itself is not so expensive, and its installation is also not difficult. Therefore, do not hesitate - read the special publication on our portal, which will tell you both how to choose the right one and how to do it yourself.

Prices for different types of circulation pumps

circulation pump

Other uses of bypasses in a heating system

Bypass in the collector unit of the water heated floor system

In autonomous heating systems that are complex in their structure, a collector circuit is usually used. This is especially important in cases where it is necessary to maintain different temperatures and pressures of the coolant in different dedicated circuits.

As a rule, this occurs in systems that include water-heated floors. High temperatures are unacceptable in them, and the exact pressure indicators in each individual circuit (and there may even be several of them in one room) depend on its length and the diameter of the pipes used for laying.

To achieve precise balancing of each circuit, special collector-mixing units are used. They are usually equipped with their own circulation pump, special thermostatic devices that ensure mixing of coolant flows from the supply and return pipes in order to reach the required temperature level. In addition, they help balance the pressure in branched circuits.

The circulation pump of this module cannot smoothly change the pressure it creates - at best, there are two or three stages of adjustment. Precise adjustment of pressure and performance for each circuit is carried out by individual balancing valves. And in the design of some similar mixing units, the developers also include a bypass, with its own balancing valve.

Judging by the reviews of experienced installers of “warm floors”, some of them consider the bypass in this scheme to be practically an extra detail. Indeed, you can find many examples of commercially available mixing and collector units without this element. However, it also performs a certain role, in particular, it protects the circulation pump of the module from overload. Excess coolant pressure, unclaimed in the “warm floor” circuits, is simply discharged through a well-balanced bypass into the “return”, thus preventing unnecessary pressure surges.

You might be interested in information about what it is

Bypass creating a “small circuit” of a solid fuel boiler

If you look closely at the correctly executed piping of a solid fuel boiler of a heating system, you will often notice that in the immediate vicinity of it the main supply and return lines are connected by a bypass jumper. What is it for?

The fact is that the operation of such a boiler is the most difficult to regulate, and the temperatures when burning solid fuels always reach, in contrast to gas equipment, very high values. In addition, the process of burning wood in any form or coal is necessarily accompanied by a large amount of smoke containing a mass of solid suspensions that settle in the form of soot.

When starting such a boiler, at the initial stage, when cold coolant enters it, due to the very large temperature difference on the outer walls of the heat exchanger, massive condensation begins. And this is a direct path to rapid overgrowing of both the internal gas channels of the heat exchanger and the chimney pipe with soot, since it sticks well to a damp surface. In addition, cast iron boiler heat exchangers really do not like such “thermal shocks”. And for steel heat exchangers, such differences often become a “trigger” of corrosion.

There is only one way out - to minimize the time of this warm-up cycle, when the temperature of the coolant at the inlet to the boiler (in the “return”) and in the supply pipe are strikingly different. But how to do this if you have to warm up a considerable volume of the entire heating system?

This is why a small circulation circle is created through the bypass mentioned above. In such a short area, heating will occur very quickly, and the process of condensation will stop. And at the lower point of the bypass, on the return line, there is a thermostatic valve or three-way valve, preset to a certain temperature.

Three-way thermostatic valve, stopped on the small boiler circuit, at the intersection of the bypass and the return line

As soon as the temperature of the coolant circulating only through the small circuit reaches the set value (usually about 55 - 60 ºС), the valve will begin to open slightly and gradually “put into circulation” cold water from the return line. Mixing with hot water entering through the bypass will ensure stability of the temperature of the liquid entering the boiler heat exchanger. Such a smooth transition of the boiler to its design power helps to avoid a lot of unpleasant consequences, and in general, significantly extends the service life of the equipment and the entire heating system.

It is not planned to consider the installation of bypasses in the mixing units of heated floors and in the small circuit of a solid fuel boiler in this article. Firstly, such work must still be carried out by appropriate specialists - amateur activities are not welcome here. And secondly, these topics deserve a separate detailed consideration, which will certainly be carried out and published on the pages of our portal. Stay tuned for upcoming articles.

In modern construction, when installing heating systems, a bypass is necessarily used. This element significantly simplifies the maintenance and repair of any elements of the heating system, and also has a positive effect on the efficiency and economy of heating. This article will discuss how to properly install a bypass in a heating system.

Bypass device

A bypass is a bypass part of the pipeline that ensures the coolant moves along a path that bypasses a certain section of the pipeline. One edge of the circuit is connected to the supply pipe, and the second to the return pipe. Various elements of the heating system, such as pumps, are usually installed on the bypass.

At the connection point between the bypass and the inlet pipe of the device that needs to be bypassed, a shut-off valve is installed. Its presence makes it possible to direct the flow of liquid parallel to the device itself and regulate the intensity of the coolant supply. A valve is also installed on the return pipe, which allows you to exclude a section of the pipeline from the system without the need to stop it.

Types of bypasses for heating

When installing a bypass, shut-off valves are installed not only on the pipes of the connected device, but also on the bypass itself. The type of fittings used allows us to classify several types of bypasses, each of which is suitable for certain operating conditions.

The following types of bypasses exist:

• Unregulated;
• With manual control;
• Automatic.

The characteristics of devices with different types of shut-off valves have significant differences, so before installing a bypass in the heating system, you need to carefully consider each type.

Unregulated bypass

The device of unregulated bypasses is a simple pipe that does not have any equipment. The pipe is constantly in an open state, and the liquid moves through it arbitrarily, that is, there is no opportunity to influence the intensity of the water flow. Unregulated bypass pipes are most often used to connect heating appliances.

When designing a heating system, it is necessary to take into account the fact that water always moves primarily through those areas where the hydraulic resistance is minimal. In the case of a bypass, this means that the internal diameter of its vertical section must be smaller than the internal cross-section of the main pipeline. If this requirement is not met, the coolant will simply gravitate toward the bypass.

When designing horizontal heating distribution, other rules apply that must be taken into account before making a bypass into the heating system. The heated coolant has a reduced specific gravity and always tries to move upward. In order for the system to operate normally taking into account this rule, the diameter of the lower part of the bypass must match the diameter of the main line, and the cross-section of the pipe leading to the radiator must be smaller.

Bypasses with manual adjustment

Bypasses that are adjusted manually (manual bypasses) are equipped with ball valves. The use of ball valves is determined by the fact that they do not change the pipeline capacity at all when switching, since the hydraulic resistance in the system does not change. This quality makes the ball valve an optimal option for bypass.

Shut-off valves of this type allow you to regulate the volume of liquid that passes through the bypass section. When the tap is closed, the coolant moves in full along the main line. The operation of ball valves has one important nuance - they need to be turned regularly, even if there is no need to adjust the system. This is due to the fact that if left stagnant for a long time, the taps may become tightly stuck and will have to be replaced. Sometimes a heating system feed valve is also installed, which plays a significant role.

Manual bypasses in heating systems can be used in several ways. Most often they are used to connect batteries to a single-pipe main, as well as for piping circulation pumps.

Automatic bypasses

Bypasses with automatic adjustment are usually installed in the piping of a pump installed in a system with natural coolant circulation. Such heating systems can operate independently, but thanks to the pump, the speed of fluid movement along the circuit increases, which reduces heat losses and increases heating efficiency.

The presence of an automatic bypass in the pump piping allows the system to independently regulate its operation, i.e. no human intervention required. When the pump is running, the coolant passes through it, and the bypass is closed at this time. When the pump stops, the bypass opens and the liquid moves in it, while the stationary pump impeller cuts off the coolant flow.

Automatic bypasses are divided into two types:

• Valve;
• Injection.

The design of the first type of device contains a check ball valve. The hydraulic resistance of the valve is minimal, so the liquid easily moves on its own. When the pump is turned on, the coolant begins to move faster, is transported into the main line and diverges in two directions.

Further movement of the liquid occurs without any obstacles, and the reverse flow is blocked by the valve. The operating principle of the valve itself is extremely simple - the hydraulic pressure on the outlet side exceeds the inlet pressure, so the ball is pressed closely against the seat of the structure and does not allow the fluid to move.

Valve bypasses are quite convenient and simple, but they are very demanding on the quality of the water with which the heating system is filled. If the water contains various impurities, such as rust or scale, the valve very quickly becomes dirty and becomes unusable, as a result of which it has to be replaced.

Injection bypasses are devices similar in principle to a hydraulic elevator. A pumping unit is installed in the main line, which is connected to the main circuit using pipes of smaller diameter. With this scheme, both pipes are inserted into the main pipeline.

When the pump starts, part of the liquid enters the nozzle and is passed through the apparatus, accelerating many times in the process. The outlet pipe, which is slightly narrowed and visually resembles a nozzle, which ensures efficient pumping of liquid, also works to increase speed.

A vacuum is created behind the outlet pipe, due to which the coolant begins to be sucked out of the bypass. The flow, moving under pressure, pulls all the liquid with it, and it continues to move along the main highway with noticeable acceleration. This effect allows you to completely prevent the possibility of reverse flow of liquid.

The technology described above only works when the pump is turned on. If the pumping equipment is turned off, then the coolant in full passes through the bypass under the influence of gravitational forces.

Bypass purpose

The main function of any bypass is the ability to keep the heating system in working order even if one of its elements breaks down or there is a power outage. Devices connected via bypass can be disconnected from the system without any problems - to do this, you just need to turn off both taps, and the coolant will flow around the circuit.

Thanks to the bypass, heating can continue to operate in any case, and damaged elements can be repaired, spending any amount of time. The reliability and ease of maintenance of the heating system with a bypass increases many times over.

In autonomous heating circuits, the bypass is used to solve the following problems:

• Connecting heating devices to single-pipe wiring;
• Pumping equipment piping;
• Connecting the water heated floor distribution manifold;
• Formation of a small circulation circuit when using solid fuel heating equipment.

The bypass installation method may vary depending on its purpose in a particular heating system.

Bypass for radiator

In single-pipe heating systems, batteries are best connected using a bypass. For two-pipe circuits and manifold distributions, bypasses are not needed, since all heating devices are connected in parallel, and each of them receives coolant at the same temperature. If one of the batteries fails, it can always be removed without turning off the heating system (of course, if there are shut-off valves).

In systems with single-pipe wiring, the batteries are connected in series, so the coolant in each subsequent device cools down. The result is obvious - distant devices receive much less heat, and there can be no talk of any uniform distribution of thermal energy.

Bypasses can solve the problem. The supply and return circuits are connected by a jumper, which ensures independent flow movement. The hot coolant enters directly into the radiator, while the other part of it passes further and at the outlet is mixed with cooled water from one radiator. This scheme allows you to deliver much more heat to subsequent heating devices.

Connecting the pump via bypass

It is advisable to connect the circulation pump via bypass only in those systems that were originally designed for natural circulation, i.e. they must have an accelerating manifold, pipe slopes must be observed and their diameters must be correctly selected. The pump in such systems is not intended to ensure their operation, but to increase efficiency.

For systems that were designed for forced circulation at the design stage, a bypass is simply irrelevant. Such systems operate only due to the pump, so when it is turned off, the circulation of the coolant simply stops. Bypass in this case will not solve the problem.

When connecting the pump via a bypass line, it becomes possible for counterflow in the bypass. In addition, a closed circulation loop is formed between the pump and the bypass itself. In order for such a circuit to function normally, the bypass device must be equipped with a ball valve or check valve.

When the pump is running, the device blocks the flow of liquid through the bypass pipe. The valve does this work automatically, but the tap has to be adjusted manually. When the pump stops, the bypass opens, which allows coolants from different circuits to mix. A similar scheme is not applicable in the case of injection bypasses - they completely eliminate the possibility of reverse coolant flow.

For heated floors

When installing a heated floor, it is imperative to install a mixing unit, in which a bypass pipeline is always built in. The bypass in this case will be used to ensure the normal operation of the heated floor, and without this element the heating will not be able to function.

It's all about the operating temperature, which must be maintained in heated floors. The coolant in the supply circuit can heat up to 80 degrees, but in a heated floor its temperature should not exceed 45 degrees. The liquid is brought to the required temperature in a mixing unit, which passes only the required volume of hot water. The entire remaining flow is directed to the bypass, where it is connected to the coolant from the return circuit, and returns to the boiler.

For systems with solid fuel boiler

When used in combination with solid fuel heating equipment, the bypass allows the formation of a small circulation circuit. To do this, the bypass pipe is installed in the supply, where there is a coolant heated to the limit, and is connected to a three-way valve located on the opposite side of the structure.

Thanks to the valve, hot water from the bypass and cold water coming from the return circuit are mixed. As a result, a coolant whose temperature exceeds 50 degrees is returned to the boiler for the subsequent heating cycle.

The need to return warm liquid to the boiler is determined by the fact that otherwise condensation will appear on the metal walls of the combustion chamber, which will provoke corrosion and cause damage to the unit. If you supplement the system with a bypass, then these problems can be easily avoided.

Bypass installation

Including a bypass in different types of systems has its own nuances, so before making a bypass for heating, you need to understand these points.

For example, when connecting radiators via bypass, the following rules must be observed:

• The internal cross-section of the bypass should be one step smaller than the diameter of the main pipe;
• The bypass must be installed at a minimum distance from the radiator;
• When used in apartment buildings, the bypass cannot be equipped with a tap.

Installation of a heating system bypass can be carried out both when installing a new system, and when repairing an existing structure. In the latter case, before work you need to prepare a set of pipes of suitable diameter, two tees and shut-off valves.

The inlet pipe of the structure is equipped with one of the following devices:

• Ball valve, which has minimal hydraulic resistance and completely allows coolant flow;
• A valve that allows you to manually adjust the intensity of liquid flow;
• A combination of a ball valve and an automatic thermostat - this combination can adjust the operation of the system automatically.

The outlet pipe is always equipped with a ball or shut-off valve. To connect individual elements, welding or threading can be used. Regardless of the type of connection, it must be airtight. Before putting the system into operation, you need to check it for leaks.

A bypass with a pump in the heating system is installed taking into account the following points:

1. The bypass on which the pump is planned to be installed is usually part of the main line. The internal diameter of the bypass must be large enough to ensure normal natural circulation in the system. The pump is mounted on a separate pipe, the internal cross-section of which may be smaller than the diameter of the main pipeline.
2. To simplify your work, it is best to buy a pre-assembled pump unit with the necessary parameters. It is very simple to install such a structure, since all the elements are already correctly assembled and the connections are quite reliable.
3. When installing it yourself, the pump must be positioned so that the impeller axis is horizontal. The surface with the terminals to which power is supplied should be directed upward - firstly, this will simplify access to the contacts, and secondly, it will eliminate the possibility of liquid getting on the contacts if the system’s seal is broken.
4. The area with a bypass must be equipped with a check valve or ball valve, which prevents the flow of coolant in the opposite direction - this optimizes the operation of the system. Of course, before installing the bypass, you need to purchase all the components.

Before installing a bypass with a check valve for the circulation pump, you need to think carefully about the design of the future system and take into account all possible nuances.

Conclusion

The bypass is a simple design that allows you to solve a wide range of problems. The presence of this element in the heating system allows you to make all its elements independent of each other, which is very useful during setup and maintenance. Knowing how to properly make a heating bypass will allow you to create a reliable and efficient design.

Bypass for heating

We have previously talked about. Today we will dedicate an article to single-pipe circuits, or more precisely, the importance of a bypass for heating. Let's figure out what it is and why it is needed. We will consider several options for installing a bypass in a single-pipe heating system separately, since each of them has different requirements. At the same time, its functions remain unchanged, which cannot be said about its location in space and relative to other equipment, as well as its diameter.

Why do you need a bypass?

A bypass is a bypass, an ordinary section of the main line, which must be installed at the required key points of the circuit. It’s worth noting right away that bypass for heating is used only in single-pipe circuits. The difference between a one-pipe heating circuit and a two-pipe one is that in the first, the coolant circulates through one line. It starts from the boiler room and ends there, while the water passes through a chain of radiators, in each of which it gives off part of its heat.

The key point that distinguishes the two-pipe scheme is the fact that the supply and return flows are separated. Therefore, a bypass in a two-pipe heating system is simply not needed. While in a single-pipe circuit, the supply and return are inseparable and are a single flow. The bypass is installed in single-pipe circuits, which can be located in different planes:

• vertical;
• horizontal.

Based on this, the installation of a bypass in the heating system is also different. Vertical contours are installed in buildings whose height is more than one floor. Horizontal - in one-story houses and apartments. To understand the principle of operation of the bypass, let’s consider its action at different points of the installation. Where can a bypass route be installed:

• on a pump that pumps the coolant flow;
• on radiators.

In both cases, the bypass path serves to ensure that circulation in the heating circuit does not stop even if the above equipment breaks down. Why is a bypass needed in a heating system? This is a backup channel through which the coolant continues its circulation along the circuit and thereby prevents . Let's look at the principle of operation of the bypass for each of the above installation options separately.

Installation on the pump

Bypass for circulation pump with ball valve

Why is a bypass needed in the heating system in the area where the electric pump is installed? It would be more accurate to say that the pump is installed directly on it. This is practiced when an electric supercharger is installed in a gravitational circuit, one in which circulation is carried out by gravity. It increases the flow rate and thus the efficiency of the circuit becomes higher. This is due to the fact that at a higher speed the coolant reaches the outermost radiator with less heat loss.

There are two options for installing a bypass for the circulation pump:

• to a new circuit;
• onto an existing circuit.

There is no difference in installation. What you need to pay attention to is the presence of shut-off valves on the central line between the bypass pipes. This is necessary to ensure that the coolant passes through the bypass for the circulation pump, and also to prevent the creation of reverse flow.

It is imperative to install a ball valve, and not a check valve, as some plumbers do.

To understand why, let's look at how it works step by step:

• when the pump operates, it accelerates the coolant;
• water from the bypass enters the main line and begins to move in both directions;
• in one direction (the desired direction) it goes unhindered, and in the second side it encounters a check valve;
• the valve closes and thereby prevents circulation in both directions.

That is, the water after the pump puts more pressure on the valve plate than before it, since the speed of the coolant behind the pump will be higher. As planned, when the pump is turned off, the coolant stops putting pressure on the check valve and does not close it. This allows water to circulate by gravity along the main line without entering the bypass. In practice, a heating bypass with a check valve does not work as expected.

The fact is that the check valve plate creates a strong hydraulic resistance equal to one meter. In a gravity circuit, the coolant simply cannot withstand such valve resistance and circulation will stop.

Therefore, before installing a bypass in a heating system with a check valve, you need to understand that in fact, installing a pump on the bypass will not make any sense. With such success, it could be installed directly on the main line, while deliberately abandoning the possibility of using the heating circuit autonomously. Is a bypass needed in the heating system in this case? It turns out that no.

If, instead of a check valve, you install an ordinary ball valve, then you yourself will be able to control the vector of water circulation along the circuit. Let's look at how to make a bypass into the heating system on which the pump will be installed. In this scheme, it consists of separate elements:

• threaded pipes that are welded into the main line;
• ball valves - installed on both sides;
• corners;
• coarse filter - placed in front of the pump;
• two American ones, thanks to which the pump can be removed for inspection or repair.

If you make a bypass in the heating system with your own hands, it is important to ensure the correct location of the pump on it. The impeller axis should be horizontal, and the terminal box cover should look up. If the terminal box cover faces down when installed correctly, its position can be changed by unscrewing the four bolts on the housing. This arrangement is necessary so that there is free access to the terminals responsible for power connections, as well as to prevent coolant from entering them in the event of a leak.

Installation on a radiator

Bypass on the heating radiator

In the area where the battery is located, a bypass is installed in a single-pipe heating system so that if circulation in the radiator stops, water can flow freely further along the circuit. In a vertical scheme, the radiator is connected to the riser by two pipes. The bypass on the heating radiator connects these pipes to each other and is installed in front of the battery. There should be no shut-off valves between the central line and the bypass in order to eliminate the human factor or the possibility of blocking the circulation in the event of a valve breakdown.

Functions of the bypass installed in front of the radiator:

• ensuring continuous circulation along the main circuit ring;
• coolant temperature regulation.

In single-pipe circuits, the coolant passes through the radiators, giving off some of the heat, and is drawn into the further flow. Accordingly, the coolant reaches each subsequent radiator a little colder.

Installing a bypass for heating makes it possible to mix the coolant from the central line with that which has passed through the battery, thereby increasing its temperature.

It turns out that if our water was 80 degrees before the first battery, then after it it will cool down to about 70 degrees. The coolant that passes through the bypass does not suffer such heat loss, therefore, when mixing liquids, the temperature of the total flow rises to approximately 75 degrees.

The horizontal single-pipe heating circuit works on the same principle, only the circuit in it is in a horizontal position in the area under the battery. At the same time, for proper circulation it is necessary to select the required bypass diameter in the heating system.

Bypass diameter

Diagram of pipe sizes in a system with a bypass on the radiator

So, we already know why a bypass is needed in a heating system and where it is installed. It remains to figure out what diameter it should be. We must consider options for installing the heating system bypass on the battery and pump separately, since its diameter will be different in each case, which is determined by different requirements for it.

The bypass on the pump will have a smaller or the same diameter as the main line. How to properly make a heating bypass, there is no fundamental difference in this case. After all, it is installed only so that if the pump is turned off, circulation can continue by gravity.

Accordingly, it is impossible to narrow the line itself, and the diameter of the pipes that extend from the circuit is not of key importance. When the pump stops, circulation through it will be impossible, therefore, even if the diameter is equal to the common line, the bypass will not change the vector of movement of the coolant. And when we need water to flow through the pump, we simply block the path of the coolant with a ball valve installed on the line.

But when installing a bypass in the heating system of a private house on radiators, its diameter is of great importance. It should be one size smaller than the pipes connecting the radiators to the central line. In this case, the leads to the batteries should also be one size smaller than the main circuit. How it works:

• water flows along the circuit and reaches the area where the batteries are installed;
• encountering a branch, the coolant changes the vector of movement in the direction where the resistance is less;
• part of the coolant continues to move along the same vector.

If the diameter of the pipes is the same as the bypass, then a small amount of water will enter the batteries, and accordingly, the temperature of the radiators will drop. If the diameter of the pipes is smaller than the diameter of the bypass, the circulation in the battery will stop altogether.

Reducing the diameter of the pipes in relation to the main line increases the speed of the coolant, which allows it to move more intensively through the radiator. In this case, water circulates throughout the battery, as a result of which it warms up evenly.

For example, consider a bypass device in. If the diameter of the main line is 32 mm, then the cross-section of the pipes through which water enters the batteries should be 25 mm. The diameter of the bypass in such a scheme, accordingly, should be 20 mm. In this case, the coolant will flow to the outermost battery along the path we need with minimal heat loss. This will make it easier to balance the system.