The bypass line serves to. What is a bypass and why should it be installed in a heating system. Manual device

Even the most minor failures in the work of engineering communications can potentially develop into acute problems and, as a result, cause serious discomfort for all households. That is why prudent owners try their best to prevent such inconveniences by installing various kinds of auxiliary devices in their homes. One of them is a bypass, which is actively used in systems and. We will talk about it further: let's figure out what kind of device it is, what are the principles of its operation, what are its advantages and why it is needed. And finally, we will tell and show a video on how to install a bypass valve with your own hands.

Design and principle of operation

Structurally, the bypass is a jumper pipe with shut-off and control valves. Its main task is to create a parallel flow of the working fluid bypassing a certain device of the engineering system. In other words, the bypass creates a bypass line.

The principle of operation of the device is extremely simple: during the normal operation of the heating or water supply system, the jumper freely passes the flow of liquid through itself, but as soon as this flow needs to be limited, the bypass shut-off element closes and the liquid begins to bypass a certain section of the system. Such blocking is possible due to the difference in the diameters of the bypass itself and the supply pipe - the first is always less than the second.

There are many benefits to using a bypass. Firstly, maintenance of heating and water supply systems is greatly simplified. Secondly, with a large number of heating batteries, the overall efficiency of the system increases and energy costs decrease. Thirdly, the problem of airing pipes and batteries due to their depressurization disappears. Fourthly, it becomes possible to use the equipment even in emergency and emergency situations. How do all these benefits become a reality? Let's find out by getting acquainted with the features of the use of jumpers in various engineering systems. But before that, let's find out what modern bypasses are.

Varieties of bypasses

Bypasses are classified according to two criteria:

• type of valves;
• appointment.

By the first sign, two types of bypasses are distinguished:

Important! An automatic bypass with a valve can only be installed in those heating and water supply systems that use exclusively clean media - scale, scale, rust and other impurities, if they get on the valve, can cause its deformation, due to which the locking mechanism will no longer close completely.

Based on the purpose, bypasses are divided into:

• radiator - installed on the approaches to and used to turn them off if necessary;
• pumping - mounted together with pumps and used either to change their operating mode, or to completely turn off;

Application features

Most often bypasses are used for such purposes:

• Maintenance of individual devices without stopping the entire system. If for some reason you need to remove equipment in the heating system or on the water supply line, for example, to repair or replace it, you just need to turn off the inlet and outlet valves of the working medium and then the liquid will go through the bypass, and you can dismantle the necessary device without consequences .

• Improving the operation of a single-pipe heating scheme. The main disadvantage of a single-pipe system is the uneven distribution of the coolant: since the batteries are connected in series here, the working fluid cools down as it moves and the last devices get an almost cold carrier. To avoid this, a bypass is installed in front of each radiator - thanks to it, a certain part of the carrier moves around the batteries and, as a result, comes hot even to a distant device.

Advice. Similarly, you can regulate the heat transfer of radiators in a two-pipe system - just turn off the tap in the selected place, and the hot carrier will move to those areas that really need heating.

• Maintaining the operation of the heating system without power supply. If the system uses an electric pump, then it is logical that when the power is turned off, it will stop working and stop the heating process. But the bypass will also save in this situation: by shutting off the pump supply valve and letting the carrier move through the jumper, you can activate the natural circulation of the liquid and restore the system to working capacity.

Bypass installation

To perform a competent installation of the bypass, it is necessary to take into account the following rules and nuances:

• the diameter of the jumper must be narrower than the diameter of the pipe to which it is connected, otherwise the carrier simply will not enter the supply device;
• the bypass should be as far away from the riser as possible - it should be located as close as possible to the device that it will serve;
• the jumper must be located horizontally to avoid the effect of airing;
• all media must be drained from the system before mounting.

Direct installation can be done in two ways.

The first is by welding. First, remove the device that will block the bypass - most often it is a battery, so we will consider the process using its example. Then, in the most convenient place of the supply pipe, make holes according to the diameter of the jumper, insert it tightly and weld it. Next, on the thread where the radiator used to be, install the shutoff valves. At the end, put the battery in a new place, connect it to the system and fix it with brackets on the wall.

The second is with clutches. Here also remove the device first. Then screw the bypass onto the inlet pipe using factory couplings, and install shutoff valves on opposite edges. Next, transfer the fasteners of the removed device, put it in a new place, connect and fix it with brackets.

As you can see, at first glance, the simplest pipe section, which acts as a bypass jumper, can help in many situations. The bypass successfully covers a wide variety of needs in water supply and heating systems - from maintaining operation at critical moments to protecting equipment, so that without its installation, the full functioning of utilities will be very difficult.

What is bypass: video

Anyone who has even a little experience with engineering networks is probably familiar with the term "bypass". In simple words, this is a bypass line along which water can flow due to various circumstances. In the article we will consider these circumstances and figure out what role the bypass plays in the heating and water supply system. We will also show you how to properly mount it with your own hands if necessary.

Bypass functions in the heating system

Let us clarify that a bypass is a pipeline designed to flow water around a certain section of the main line where any equipment is installed. In heating schemes, it can be found in two places:

• in single-pipe systems as a jumper on radiators;
• on the distribution manifold of water heated floors.

As you know, in a single-pipe heating system, the heat transfer of the first battery affects the operation of the next one, and so on. This applies to both vertical and horizontal layouts. If the bypass setting in the heating system is not done, then the radiators will be connected in series. As a result, the first of them will take away the maximum amount of heat, the second - all that is left, and the share of the third will fall only to the cooled coolant.

To prevent this from happening, the supply and return near each battery is connected by a jumper, whose task is to direct part of the coolant around the radiator. In this case, the principle of operation of the bypass is to transfer the same part of the heat to the near and far heaters and reduce their dependence on each other. How this is implemented can be seen in the figure:

Important. In the shown vertical system, the bypass device is provided so that the diameter of the pipe is smaller than the main line and slightly offset from its axis to the side. The goal is to prevent the coolant from passing under the influence of gravity in a straight line, past the radiator. In a horizontal system, the main pipe itself is a bypass, while it does not move anywhere and everywhere remains the same flow area.

In the heating system, a bypass is needed to evenly distribute heat across the batteries, as well as to carry out their repair or maintenance. If for some reason it is necessary to disconnect and remove the heater, then it is enough to simply close the 2 taps installed at the inlet and outlet of the coolant. Then the water will go along the bypass through the jumper.

But the bypass for heating on the collector of a water-heated floor plays a different role. Here the bypass line is part of the mixing unit with a three-way valve. The task of the node is to prepare the coolant of the required temperature for supply to the heating circuits of underfloor heating. Indeed, in these circuits, the water temperature does not exceed 45 ºС, while in the supply line it can be 80 ºС.

In normal mode, the three-way valve passes hot water from the system to the warm floor in a limited amount. The rest of the coolant passes through this automatic bypass, mixes with cold water from the collector and returns back to the boiler. Since the temperature difference between the main and the collector is significant, the bypass line is used constantly. It turns out that without it, the normal functioning of underfloor heating is impossible.

Bypass in the boiler room

In boiler piping schemes, a bypass line is also necessary in 2 cases:

• as a bypass for a circulation pump;
• for organizing a small circulation circuit for a solid fuel boiler.

A pump installed on a bypass pipeline is found in heating systems quite often, sometimes even without special need. The fact is that a one-pipe or two-pipe heating system, originally conceived with forced circulation, can never function when the pump is turned off. She does not have large slopes and increased pipe diameters for this. But the bypass for the pump is exactly what is needed so that the water can flow in a straight line, while the pumping device is not working.

Hence the conclusion: when connecting a system designed for forced circulation to the boiler, it is not necessary to put the pump on the bypass. Turning off and removing the unit in any case will stop the movement of the coolant, so the pump is installed in a straight line.

Another thing is a system adapted to the natural movement of water. It often happens that in order to increase efficiency, a pump is not simply built into it, but a bypass system with a check valve on the line is installed. This allows, in the event of a power outage, to automatically switch to natural circulation, which is reflected in the diagram:

While the pump is running, it presses the valve on the back side with its pressure and does not let the flow flow in a straight line. One has only to turn off the electricity or close one of the taps, as the pressure disappears and the bypass valve opens a direct path to the coolant, the convective movement of water is restored. You can safely remove the pump or clean the sump, the operation of the system will not be disturbed by this, it will simply switch to another mode.

Well, the last place of application of the bypass is the small circulation circuit of a solid fuel boiler with a mixing unit. Here, a jumper connected to a three-way valve allows the heat generator to warm up to a temperature of 50 ºС in order to avoid low-temperature corrosion on the steel walls of the furnace. In this case, the bypass circuit looks like this:

The principle of operation is simple: the valve does not allow cold water from the system into the boiler until the coolant circulating through the bypass line is heated to the required temperature. Then the valve opens and passes cold water into the circuit, mixing it with hot water. Then condensation does not form on the walls of the furnace and corrosion does not occur.

Sometimes a bypass is needed in the water supply system. For example, to remove for repair, washing or replacing a heated towel rail in the bathroom. Since it is connected to the DHW riser, its dismantling in an apartment building will create a lot of inconvenience. It is easier to foresee this in advance and put a jumper with a tap when installing the heater.

How to install the bypass

The complete set of the underfloor heating distribution unit also includes a bypass line, but this is a topic for a separate discussion. As for jumpers on a single-pipe system, their installation is very simple and is done already during the installation of the system, since without them the latter will not work correctly. It is not much more difficult to do a do-it-yourself installation of a bypass line with a circulation pump. It is enough to have the usual set of tools and study the scheme:

Advice. In order not to dial all the parts separately, you can buy a ready-made assembly, shown in the figure below:

It is not difficult to install a bypass for a heated towel rail. For connections, you can take metal-plastic pipes, and even purchase taps, tees and bends. Assembly is carried out in accordance with the scheme:

Conclusion

It turns out that an ordinary pipe segment, which is a bypass line, can play an important role in many cases. Here it ensures the operation of the system, there it helps to distribute heat, and sometimes protects the equipment. In all of these cases, a bypass is indispensable.

Through the bypass in the heating system of a modern house, all its key elements are mounted. This simple engineering solution facilitates the maintenance and repair of equipment connected to the trunk. And it also increases the efficiency and economy of heating, which is not bad at all, right?

Want to add a bypass to your heating system, but don't know how to do it right? We will help you cope with the task - the article discusses the purpose of this element of the heating system and the key points of its installation.

Bypass, or bypass bypass, is a pipeline that serves to organize the flow of coolant around a certain section of the heating main, or parallel to it.

Most often, some equipment is installed on this site. One end of the bypass pipe is connected to the inlet pipe, the other - to the outlet.

Shutoff valves are installed between the bypass and the inlet of the bending device. It allows you to completely redirect the flow of water along an alternative path, or to regulate the amount of liquid entering the device.

To be able to completely turn off the equipment, a valve is also installed on the outlet pipe - between the outlet of the device and the bypass.

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Since the hydraulic pressure from the side of the outlet is higher than from the side of the inlet, the ball is tightly pressed against the valve seat and completely closes the lumen of the pipeline.

A bypass is a bypass line through which water can pass. In our article, we will consider what the bypass is used for, as well as the functions and rules for installing the device.

Bypass functions in the heating system

Bypass is a pipeline that is used for the flow of water around any section of the highway.

In the heating system, it is installed in the following places:

1. In water heated floors, it is installed on the distribution manifold.
2. In a single-pipe heating system, a bypass is installed on the radiator as a jumper.

Regardless of whether you have a horizontal or vertical heating scheme, heat transfer from one battery affects the next, etc. If there is no bypass in the system, then the maximum amount of heat will be in the first radiator, and the subsequent ones will be supplied with less and less. In order to avoid such a situation, it is necessary to connect the supply and return pipes with a jumper near each battery. And she, in turn, directs a certain amount of heat carrier around the battery.

With the help of a bypass, the same amount of heat will be distributed to all heating radiators.

Another bypass is required for maintenance and repair of the system. In the event that it is necessary to disconnect and remove the heating device, it is possible to close the two taps that are installed at the inlet and outlet of the heat carrier. In this case, the water will bypass through the jumper.

In a water heated floor system, the bypass functions are different. The bypass line is part of the 3-way valve assembly. The function of the node is to heat the heat carrier to the required temperature. And he gets into the heating contours of the warm floor.

The temperature in the circuits cannot exceed 45°. And in the supply line, it can reach 80 °.

During normal operation, hot water from the system flows to the floor in a small amount. And the rest of the heat carrier passes through the bypass and mixes with cold water from the collector. And then back to the boiler. Since there is a large temperature difference in the collector and the line, the bypass line works constantly. Therefore, without a bypass, normal operation of the water floor heating system is impossible.

Pump types and bypasses

When installing this device, you need to pay attention to the type of pump that is used in the heating system. The node is installed on the main highway.

There are two types of pumps:

1. "Wet". In this type, the rotary impeller is located in the water. The wet type pump can be installed on the return and supply pipes.
2. "Dry". The rotor in such a pump does not come into contact with the coolant. The disadvantage of the dry type pump is the noise during operation. Therefore, it is desirable to use it in a boiler room with good sound insulation. You can install the unit on the return pipeline.

Bypass installation

It is possible to install a jumper in a single-pipe system during the installation of the heating system for its high-quality operation. Setting up a bypass is a simple process. You can install a bypass line with a circulation pump yourself after studying the diagram, and you also need to purchase the simplest set of tools. And also for ease of installation, it is recommended to purchase a ready-made assembly. Then you do not have to collect each part separately.

Bypasses are also installed on heated towel rails. The installation process is not difficult. For installation, you will need to buy bends, taps, tees, and you can also use metal-plastic pipes for connection.

Bypass in the boiler room

For piping heating boilers, a bypass line is sometimes necessary. Consider the cases when it is necessary to install it:

• In solid fuel boilers for organizing a small circulation circuit.
• For the pump as a bypass.

A pump is often installed on the bypass pipe. And it's not always necessary. A single-pipe and two-pipe forced circulation heating system cannot work without a pump. Therefore, in order for water to flow in a straight line, a bypass is required.

And in a system with natural circulation, work efficiency is increased. To do this, install a bypass with a check valve on the line. In the event of an unexpected power outage, it will automatically switch to the natural movement of water.

A bypass is often installed in a solid fuel boiler. It allows the heat generator to heat up to 50 ° C in order to avoid corrosion on the steel walls of the furnace.

Until the coolant is heated to the desired temperature, the valve will not let cold water from the system into the boiler. Then the valve opens and passes cold water and it mixes with hot. In this case, condensation will not form on the walls of the furnace, and, consequently, corrosion will not form.

And also a bypass is needed in the water supply. If you need to repair or replace the heated towel rail in the bathroom. Without a bypass, this will be problematic. In a multi-storey building, you will create a lot of inconvenience. Therefore, it is recommended to pre-install a jumper when installing a heater.

Bypass features

Bypasses have some features:

• When installing the bypass, pay attention to the diameter of the node. It must be less than the diameter of the supply pipeline;
• For the bypass device, it is best to use American nuts. They allow you to quickly disassemble the valves and the pump in case of any repair;
• In order to avoid air in the system, the unit can only be installed horizontally;
• It is necessary to install plugs at the top and bottom of the pipe;
• The knot can be made by hand. To do this, you need to purchase a tee, a piece of pipe and a welding machine. But you can also buy ready-made elements and assemble them using threaded contacts;
• It is necessary to install a thermostat or control valve between the bypass and battery inlets;
• Install the bypass next to the radiator, but away from the riser. The most suitable place will be where the temperature is not very high. And also the service life of the bypass will decrease if it is installed next to the heating boiler;
• A special coupling must be arranged on the bypass pipe. This is necessary for its easy removal along the thread during repairs.

If you cannot install a bypass yourself, you can invite a specialist. If the bypass is installed correctly, you will notice a significant benefit.