Bypass line device. Bypass line and bypass route. Design and principle of operation

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 jumper installed on a thermal route parallel to the main line. This uncomplicated detail in the form of a piece of pipe helps to solve diverse problems and therefore is considered an important element of any scheme. Why a bypass is needed in the heating system of an apartment and a private house is described in detail in our material.

Bypass installation options

When we have determined what a bypass line is, consider why it is needed and where it is installed. Depending on the problem being solved, the element takes the form of a bypass pipeline or a straight section connecting the supply line with the return line.

Reference. The English word bypass in literal translation means "bypass", "bypass".

There are several options for installing bypasses in heating systems:

On radiators of closed and open one-pipe systems.
Parallel to the circulation pump operating in a gravity (otherwise - gravitational) heating network.
Jumper between supply and return, forming a small circulation circuit for heating a solid fuel boiler.
in various mixing units.

In apartment buildings, where heated towel rails are connected to a common hot water pipe, a bypass line is also used, acting similarly to a radiator line (item 1 of the list). Why it is needed there, we will tell further.

Towel rail pipes have a large diameter and throughput, a jumper is needed only for convenient removal of the coil

The first two options are well known to owners of private houses and apartments. Unfortunately, some owners, who consider themselves major specialists, “improve” bypasses or put jumpers where they interfere with the normal operation of the heating system. We will also consider accidental and intentional errors.

Radiator jumpers of a single-pipe scheme

In most multi-storey buildings of Soviet construction, heating is organized with the help of single-pipe vertical risers passing through all apartments. The principle of operation of the scheme is to distribute the coolant among the batteries on floors 5-16 due to the high flow rate and high pressure.

For reference. Old cast-iron radiators and steel finned convectors were distinguished by large diameters of internal channels, whose connection to the riser was designed without any bypasses. We are talking about new generation devices with high heat transfer and lower throughput.

Options for single-pipe heating schemes for multi-storey residential buildings

Note that the radiators are connected to a single line with both connections, between which a bypass is cut. The pipe jumper is specially shifted away from the axis of the riser, otherwise the water will not flow into the battery, but will move along a straight path down or up, depending on the direction of supply. Ideally, the circuit works like this:

Having reached the fork of the first heater, the hot coolant flow is divided approximately in half - one part flows into the radiator, the second rushes into the bypass.
Having cooled down by 1-2 °С, the first stream mixes with the bypass one and returns to the main line. The temperature of the resulting mixture becomes 0.5-1 °C lower than the initial one.
The process is repeated similarly on the following heaters. To ensure that there is enough heat for all consumers, district heating pumps pump a large amount of coolant through the mains, reducing the temperature difference between the first and last battery.

In a private two-story cottage, a straight section is placed on the upper batteries

Note. Similar schemes are found in two-story private houses. And although the vertical riser supplies only a couple of radiators, it is advisable to install a bypass on the upper heater, since the performance of a domestic circulation pump is much lower than that of an industrial "colleague".

If you remove the direct bypass line, then the entire volume of water will flow through the heater and cool down by 1-3 °C. Due to the large temperature difference, each subsequent apartment will receive significantly less heat. The room with the last radiator will be as cold as a doghouse.

That is why, with a vertical single-pipe scheme, a simple piece of pipe on the battery plays an important role. In two-pipe wiring, hot and cooled coolant flows through different lines, so a bypass is not required.

Here the role of the bypass line is played by the distributing pipeline itself.

In country houses, the low performance of the circulation pump is compensated by an increase in the diameter and throughput of pipelines. This is done in the horizontal single-pipe system shown in the photo. The bypass is the main line, where approximately 2/3 of the coolant flows, and the third part enters the batteries.

Bypass line of the circulation pump

In most modern water heating systems, the pump unit cuts directly into the supply or return pipeline, which is described in detail. It is not necessary to install a bypass in this case:

when the power is turned off and the pump stops, the coolant will still not be able to circulate on its own due to the small diameters of the pipes;
to remove the pumping unit for the purpose of repair or replacement, it is enough to turn off 2 taps and unscrew the two Americans, provided that the unit is assembled correctly;
since water is unable to move along the lines without forced induction, the bypass jumper will not help keep the system working while the pump is being serviced.

This circuit can work in forced and gravity mode.

The only case when you need to make a bypass branch for the circulation pump is a gravity heating system. Firstly, the unit with connection pipes DN 25-32 cannot be cut into a Ø50 mm pipe used in the gravitational heating network of private dwellings. Such a narrowing of the diameter will stop any gravity flow.

Secondly, heat supply should work according to a universal scheme. The main mode is forced from the pump, in the event of a power outage, the transition to natural gravity flow of the coolant due to convection. To organize such heating work, the pump unit must be installed on the bypass.

There are 2 ways to mount this node:

A ball valve crashes into a straight line, and the heating pump is taken out to the bypass line along with a strainer - a sump and shutoff valves.
A ready-made bypass unit with a pumping unit and a check valve is placed in the line break.

The device of the pump unit with a shut-off valve on a straight line

In the first variant, the transition to gravity mode is done manually. When the power supply is cut off, one of the household must go to the boiler room and open a large faucet in a straight section. Otherwise, without water circulation, the boiler will stop heating, the building will get cold and you will freeze.

In the second case, after a power outage, an automatic check valve will open, which is in the closed position during pump operation. But not everything is as rosy as it seems at first glance:

Hence the conclusion: do not install ready-made automatic bypasses with a valve and a pump. It is better to assemble a knot with a shut-off valve with your own hands. The house will begin to noticeably cool down 30-40 minutes after the shutdown, which is quite enough to open the main highway.

The rubber ball rolls freely inside the chamber and closes the passage under the pressure of water

Option two: mount the bypass assembly from separate parts using a brass check valve with a free rubber ball not pressed down by a spring. How such an element looks like, look at the photo and in the video:

Mixing knots

These elements of heating systems consist of a three-way thermostatic valve and a bypass connecting the return pipe to the supply. The bottom line is this: a bypass branch helps to collect a coolant from two lines in the valve chamber, and at the outlet to get water of the required temperature.

The principle of dismounting using a jumper and a 3-way valve is used in various parts of the heating network:

small circulation circuit of a wood-burning boiler;
tying a buffer tank or a heat accumulator;
along the heating contours of a water-heated floor.

For reference. The scope of application of mixing units is quite wide. Controlled lowering of the water temperature by mixing is used in air heating units (air heaters) and other climatic installations.

Scheme with a boiler circuit that protects the heat generator from condensate

The bypass shown in the diagram with a three-way valve, forming a small circulation circuit, protects the solid fuel boiler from condensate during the heating phase. The process algorithm looks like this:

When lighting firewood and turning on the pump, the valve remains closed on the side of the heating system. Leaving the jacket of the heat generator, the water turns into the bypass line and returns to the boiler.
As the temperature of the looped coolant increases, the temperature rises. When it reaches the threshold level of 50-60 °C (depending on the setting), the valve thermoelement is activated, gradually opening the flow from the side of the radiators.
The more the water in the boiler circuit heats up, the wider the passage to the cold coolant from the system opens. Mixing occurs in the valve chamber, but the outlet flow temperature will not fall below the set threshold until the fuel has been burned.

With a cast iron heat exchanger, the bypass mixing unit plays the role of a safety element. Situation: the heating is working to its fullest, the firewood is burning, and suddenly the light goes out. If there is no safety net in the form of a UPS or an electric generator, and the power supply is resumed after 30 minutes, the water in the batteries has time to cool down.

A relief line with a bypass valve is not always found on factory manifolds, but it prolongs the life of the pump

Note that the boiler will not have time to cool down within half an hour - the firebox is full of heat and firewood. It is worth turning on the pump, as the cold coolant is injected into the boiler jacket and the cast-iron section bursts from the temperature shock. Therefore, in this case, it is impossible to do without a bypass.

A similar principle of mixing by means of a jumper and a valve is used in the distribution box. When the temperature in the heating circuits has reached the norm (35-45 ° C), the 3-way valve closes the supply side from the boiler, and the pump drives the coolant through the bypass along the inner ring.

Note. In case the automatically regulated circuits close together, the comb is equipped with an unloading bypass. Thanks to him, the pump "twirls" the water through two collectors, and does not mix inside itself, which reduces the life of the unit.

The use of the connecting jumper in the piping of the buffer tank is identical to the previous options and is shown in the diagram.

When tying a buffer tank with a solid fuel boiler, 2 bypasses are used

Mounting errors

Some home, or rather, apartment craftsmen, when replacing old cast-iron radiators with new aluminum ones, deliberately make two stupid mistakes:

a ball valve is mounted on a straight bypass pipe in order to direct all the coolant into its own battery;
after listening to the advice of "smart" people, they assemble a mixing unit with a three-way valve in order to regulate the heat transfer of the heater.

We’ll make a reservation right away that such an installation in a private house is not considered a mistake: you live there alone and manage the heating yourself. In a high-rise building, such actions harm the neighbors, because you will unbalance the system and take away more heat. This means that adjacent apartments receive less. How it happens, look at the video:

Instead of further listing the errors, we suggest that you familiarize yourself with the recommendations on how to properly install the bypass on your own:

The jumper on the battery of an apartment building is a pipe without any shutoff valves and valves. The maximum that is allowed is to reduce the diameter by 1 standard size (riser DN 20 - connector DN 15);
If you want to regulate the heat transfer of radiators, please install manual or automatic thermostats. There are special full bore models for centralized networks.
In multi-storey buildings with common risers, it is unacceptable to mount fittings on a bypass pipeline
If non-volatile gravitational heating is organized in a country house, mount the pump only on the bypass. Gravity flow is not provided - a jumper is not needed.
When self-assembling the mixing units, make sure that the circulation pump is on the side of the open outlet of the valve. Other options don't work.
, equipped with a thermal head, operates from a remote temperature sensor. Place the latter on the pipe behind the valve, where the mixed coolant exits. Then the element will be able to navigate by its temperature.

Point #3 requires clarification. For 3-way valves, one branch pipe is always open - the one from where the resulting mixture comes out. The pump is on the same side. If the unit is located on any inlet pipe, then further events will follow one of two scenarios: the circulation will stop or the coolant will go through the bypass, close in the boiler circuit and not enter the radiators.

In conclusion, briefly about DHW

Since we made all the main conclusions in the course of the description, we will supplement the information picture by installing a bypass on the heated towel rail. This is the only case when a piece of pipe is placed only for the convenience of maintenance or replacement of the heater. The element practically does not affect heat transfer due to the flow rate and pressure in the water supply system. The principle of operation is similar to the operation of a bypass on radiators, only here we distribute hot water.

A new stage of work at Teplovodokanal was an unpleasant surprise for the Pushchi residents. An obstacle to the passage appeared on another part of the Arbat - an external bypass line is being created. The director of Teplovodokanal, Albert Ryabov, spoke about the reasons, plans and timing.

For many Pushchinites, life was divided into "before" and "after" or, rather, their path - into "before" and "after". The main street of the city is blocked by a temporary line. The reason for this is the replacement of the main hot water supply line, the pipes in which have long worked out their standard period.
Albert Ryabov, director of MUE Teplovodokanal: "The Government of the Moscow Region has allocated money to replace these pipes. Competitive procedures are now being carried out to replace this route. In order not to disconnect residents from hot water supply and, accordingly, heating, an external bypass network is being laid, to which "All microdistricts, all houses will be connected. After that, the Arbat will be opened and the underground heating main will be replaced. By spring, the pipes of the external laying will be completely removed. And the coating on the Arbat will be restored."
Among the questions raised by Pushchinites, the leading one is the following: “Why is the work carried out before winter?”
Albert Ryabov, director of MUE "Teplovodokanal": "Actually, it does not matter when to perform such work. Whether in winter or summer, the bypass line should be built anyway."
The answer to one of the age-old questions "What to do?" everyone is looking for himself. There were those who, at the risk of injury, made their way under or, worse, over the pipes installed on the slabs. Recently, a transition was organized in front of the store. But soon the townspeople will have only one way - to bypass the obstacle. Most likely, the structure will have to be removed due to the pit. But, as Albert Ryabov explains, everything will depend on the production of work.
Albert Ryabov, director of MUE "Teplovodokanal": "Unfortunately, when working to replace this network, it will be impossible to cross this network. Since, firstly, the bypass line is quite high from the ground, it is 10 meters from the ground, but a wide part will still be opened Arbat, a wide part of the path. Completely. There will be a very large pit along the entire length of the Arbat, and it is impossible to go through the pit and, accordingly, also the pipes. At the same time, one must understand that it is still necessary to ensure the passage of equipment. That is, if bridge, it should be higher than the passing equipment, that is, on an effusion of about 4 meters.
The cost of one such transition, which then cannot be used anywhere else, is estimated at 500-700 thousand rubles, which, according to the director, is not adequate to the inconvenience. The device of a U-shaped arch costs about 300 thousand rubles, and the problem of overcoming the pit will still remain. Therefore, according to Albert Ryabov, there is only one conclusion - the obstacle must be bypassed.
Albert Ryabov, director of MUP "Teplovodokanal": "Yes, this will cause a lot of complaints, but the city is small, and the microdistrict is small, and a 300-400-meter detour should not cause any particular complaints."
The first bypass option is near the former Steklyashka store. The line will end near Kuznetsov Square.
Albert Ryabov, director of MUP "Teplovodokanal": "Just opposite the field near the hotel, she will dive underground, that is, she will have to go around to this field."
The director of Teplovodokanal believes that the situation with the bypass line will last about three months. The deadline “by spring” applies to the entire range of works, the bypass line will be removed earlier, as soon as the replaced heating system is launched.
Albert Ryabov, director of MUP "Teplovodokanal": "In the spring this one will be removed only because restoration work on the coating on the Arbat cannot be done in winter, it cannot be done in cold weather. Frosts and winter will not hurt to fill the pit back and, accordingly, fill it with rubble. Then there is, in fact, most likely, in winter there will already be a coating in the form of rubble on the Arbat, that is, it will be possible to walk.
Treat the detour as an outrageous problem or as an additional opportunity to walk around the city? Everyone will choose the answer to this question. Albert Ryabov appealed to the people of Pushchi with a request to be tolerant of the situation.
Albert Ryabov, director of MUP "Teplovodokanal": "Not all cities and not always allocate such large funds for such large replacements, and I believe that one can suffer inconvenience in replacing this network. I can say to everyone that my child is also studying in gymnasium, and we walk along this Arbat every day.
"Teplovodokanal", which has now become for Pushchin residents both a symbol of both discontent and hope for warmth, calls for understanding of the current situation. And Voltaire said that there are no great things without great difficulties.

Diana Larionova, Andrey Mikhailin, TVS Pushchino

Many have probably heard that in order to increase the efficiency of heating systems, a bypass is installed in them. But at the same time, people do not even realize that this is ...

Bypass - what is it and why is it needed?

By Masterweb

31.05.2018 02:01

Many have probably heard that in order to increase the efficiency of heating systems, a bypass is installed in them. But at the same time, people do not even know what it is. In fact, this beautiful word is called a pipeline parallel to the main system in one of the sections. Bypass is used in cases where the task is to constantly regulate the temperature regime in certain sections of the network, as well as to facilitate the process of replacing a heating radiator without having to turn off the entire system. Such a simple engineering solution greatly facilitates the operation and repair of the heating system. Let's look at what a bypass is, what kind of mechanism it is in various sections of the pipeline.

Characteristic

A bypass, or a bypass bypass, is a pipeline that serves to change the path of the coolant flow around a particular section of the heating system. Often such a tap is connected in parallel with the main one. Often, some of the equipment is installed on the site. At one end, the bypass pipeline is connected to the inlet pipe or branch pipe. The second is connected to the outlet.

Between the bypass outlet and the inlet of the device to be bypassed, stop valves are mounted. This allows you to completely direct the flow of the coolant along an alternative route, or to control the amount of heat supplied to the device. In order to be able to completely turn off the heating devices, the outlet pipe is equipped with shut-off equipment. It is installed between the outlet and the bypass pipe.

Types of bypass solutions

Stop valves are mounted not only at the inlet of the pipeline, but also directly on the bypass. Depending on which of the shut-off valves is used, there are three types of bypasses in the heating system. These are non-adjustable solutions, with the possibility of manual adjustment, as well as fully automatic systems. Each species has its own characteristics.

Non-adjustable spigot

Sometimes the most ordinary pipe is mounted in pipelines as a bypass without additional devices. Not many people know that this is a bypass, only unregulated. The clearance inside the pipe does not change in any way, and the coolant fluid moves through it without the ability to somehow control it. These engineering solutions are used when connecting heating radiators in apartments and private houses.

In the process of designing heating systems, it should be remembered that the coolant will move along the path of least hydraulic resistance. The diameter of the bypass, which is installed vertically, must be smaller than the size of the flow area in the main pipeline. If this nuance is not taken into account, then under the influence of gravity, the coolant will go to the bypass, and not to the heating battery.

If the heating system has non-traditional horizontal wiring, then slightly different rules work. The heated coolant will try in every possible way to get up - the specific gravity of the heated medium is lower. Therefore, the bypass device for such solutions will be different. The diameter of the inlet pipe must be close to or equal to the diameter of the line. The outlet pipe connected to the radiator is made smaller than the main line.

The reduced size of the inlet pipe of the radiator contributes to the fact that the pressure of the coolant increases. Also, the liquid is more evenly distributed along the contour of the battery or any other device for heat transfer.

Manual device

This bypass in the heating system is nothing more than an ordinary bypass pipe with a ball valve. Such faucets are best suited for heating. When open, ball valves do not reduce the clearance in the pipeline. There are no serious obstacles for the circulation of the coolant fluid.

The presence of shut-off valves makes it possible to adjust the amount of liquid that will pass through the bypass. If the valve is completely closed, then the coolant flow will move along the main path.

If the working parts in the ball valve stick to each other, then such devices should not be installed in the heating system. But if it is already installed, then periodically it is necessary to operate it - turn it, even if it is not necessary.

Bypasses of this kind are recommended for installation only in individual heating systems of private houses. The use of shut-off valves on bypass jumpers in high-rise buildings is strictly prohibited. Sometimes, through negligence, you can block the access of the coolant to other residents.

As for the scope of such adjustable outlet solutions, they are widely used when connecting radiators to single-pipe heating lines, as well as piping hydraulic pumping equipment.

Automatic devices

These systems are highly specialized. They are mounted mainly as a pump piping in gravity heating systems. The liquid can circulate through the circuits of the system without the mandatory installation of pumps or other units. An electric blower can be installed in the system - the device helps to reduce heat loss and promotes uniform heating.

The flow of liquid coolant in the system changes direction without human intervention. During the operation of the pump, the heat transfer fluid moves through the unit, and the bypass for the circulation pump is automatically closed. If a pumping equipment shutdown occurs, then the coolant will go the other way - through the bypass. The impeller will limit or make it impossible for the further movement of the coolant.

Types of automatic devices

There are valve and injection bypasses. What is it, we will consider further. In the first option, a ball valve is installed in the bypass pipe - its feature is that it creates a minimum resistance to the movement of the coolant. Also, no obstacles are created for the movement of fluid in the forward direction. As the pump runs, the flow rate increases. Water from the outlet section enters the pipeline, and then is divided into two streams. Then the movement along the circuit is carried out without any obstacles, and when trying to reverse the movement of the liquid, the bypass valve interferes.

Since the value of hydraulic resistance on the side of the inlet section is higher than on the side of the outlet, the ball in the check valve is pressed more tightly against the seat. This closes the cross section of the pipeline.

The downside of the valve bypass is considered to be particularly sensitive to the purity of the coolant. If contamination enters the liquid, the device will fail.

Next, consider the injection bypass. What it is? This is a device that works on the principle of a hydraulic elevator. In the main pipeline, it is often large. The inlet and outlet pipes continue inside.

After starting the pumping equipment, a small part of the coolant will enter the diffuser installed on the inlet pipe. The liquid will then pass through the bypass device and accelerate. The outlet pipe is slightly narrowed and resembles a nozzle in appearance. Through it, liquid under a certain pressure is ejected at high speed into the main line.

There is a vacuum zone on the reverse side of the cut of the outlet pipe. Under its influence, the coolant fluid is drawn out of the bypass. The jet drags the environment and transfers kinetic energy to it. So the flow tends further throughout the system. Such a route of movement does not allow a reverse flow to form.

When the pump is not operating, the heat transfer fluid flows through the bypass system in a natural manner without any obstruction.

Purpose

We know what this engineering solution looks like and works, but we don't know what the bypass is for. Let's look at its purpose.

The main task that the bypass element solves is to preserve the possibility of movement of the liquid coolant in the circuits and lines of the heating system if the pumps or other pumping units are out of order and do not work.

Completely, any devices that are connected in this way can be easily disconnected from the general system by shutting off the taps in the inlet and outlet pipes. Further, the entire flow will move through the bypass pipe. The device, disconnected from the mains of the heating system, can be serviced or repaired. It is even possible to completely dismantle a particular device and install new equipment instead. In this case, it is not necessary to stop the heating system, and there is also no need to drain the coolant.

Installing a bypass in individual heating circuits can be carried out in several cases. But more often, bypasses are installed due to the advantages that this solution has. The bypass is indispensable if you need to embed the radiator into the heating main with one pipe. Also, bypass pipes are required for the operation of circulation pumps. When connecting a distribution manifold in a warm floor, such workarounds should also be organized. Bypass will be very useful if you need to organize a small circuit for the operation of a solid fuel boiler.

Naturally, the connection of the bypass in different cases has certain features. This must always be taken into account.

Bypass on the radiator

Heating radiators through bypass pipelines will be connected only in the case of single-pipe lines. In two-pipe systems and in the case of collector wiring, it makes no sense to insert bypass pipes into the system. In such heating systems, radiators are connected in parallel, and each battery receives a coolant of the same temperature from the supply line. If any one of the circuits of the system fails, if there are shut-off valves, this will not affect the operation of the entire system.

In systems with one pipe, due to the connection of heat-releasing equipment, the temperature of the coolant drops as it moves along the circuit. The greater the heat dissipation of the radiator, the colder the liquid will be at the outlet. If a bypass for heating is not provided here, then the first battery will take maximum heat and be very hot, and only slightly warm liquid will pass through the last radiator.

By connecting the supply and return with a jumper pipe near each battery, the coolant flow is divided into two. One part moves to the radiator, giving off heat, and the second part, having retained the temperature, goes along the bypass and at the outlet is connected to the flow from the battery. This way it is possible to deliver enough thermal energy, even to the last battery in the system. According to this scheme, the bypass to the heated towel rail works and is connected.

Bypass and circulation pump

Circulation devices are connected through the bypass if the system is adapted for the gravity flow of the coolant. The system must be equipped with a special accelerating collector, and the slopes must be strictly observed. The diameter of the pipes must also be sufficient. A pump is installed in the line to increase the efficiency of the system.

If the heating system was conceived as forced, then in the event of power outages or the failure of the pump, it will not be able to work. The coolant will not be able to move without a pump or other unit. In such lines, pumps are installed without bypasses.

The peculiarity of connecting pumping equipment through a bypass is that a counterflow appears and a closed circulation loop appears in a circle from the bypass to the pump. In the bypass branch pipe, shut-off valves are installed - a valve or a ball valve. If the pump is operating normally, then the shut-off valves completely block the cross-section of the bypass pipe. If the element stops for any reason, then the bypass opens. The coolant starts to move.

Bypass and underfloor heating

The so-called bypass line during the installation of "warm floor" systems is part of the mixing unit. It is used constantly and without it the system will not be able to work normally. Water moving along the supply part of the pipeline has a temperature of 80 degrees and above. In the circuit, the water temperature should not be higher than 45 degrees.

To prepare the coolant, a mixing unit with a special three-way valve is used. He is able to pass only the necessary amount of water. The rest of the coolant will move along the bypass. There it will mix with the water coming out of the collector and go to the boiler.

Conclusion

Now it’s clear why the bypass is used in most private heating systems. This is a useful technical solution that makes the operation of heating equipment easier. With a bypass, you can easily clean or replace the heating radiator, and the rooms will warm up more evenly.

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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.

Bypass placement

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 .

Bypass in the heating system

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.

Bypass installation

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 valve. 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.