Mixers for hot water supply systems. What types of hot water supply systems are there? Advantages and disadvantages of an open system

Ball valve design:

Ball valve– type designed to shut off the flow of a working medium primarily with high temperatures and pressures. Locking element in ball valves - a body of rotation, a ball, along the axis of which there is a through hole for the passage of the medium. Blocking the flow occurs due to the rotation of the ball by 90° around its axis, arbitrarily located in relation to the direction of flow.

Tightness is ensured by the presence of saddle seals in the form of rings. Saddles can be made of various types of plastics, synthetic rubbers and provide ease and smooth rotation of the ball plug. Seat seal designed in such a way that as the pressure in the pipeline increases, the pressing force acting on the valve shut-off element increases. The working medium presses the ball tightly against the sealing ring. Seal material ball and rod are selected depending on the density and temperature of the working medium.

One of the advantages of ball valves is the ability to quickly shut off the flow of the working medium, but this may result in water hammer– a pressure surge caused by an extremely rapid change in the speed of fluid flow over a very short period of time. Ball valves with a passage narrowed by one standard size are called standard, or reduced. Reduced ball valves, with minimal pressure losses in the network, significantly reduce money waste, and also reduce the negative impact of water hammer. The confuser and diffuser (narrowing and widening of the passage diameter) in reduced valves are designed in such a way that the working medium does not create a large excess pressure at the inlet, and flow turbulence does not form at the outlet.

Narrowing and expanding the diameter of ball valves:

In some cases it is preferable to use full bore ball valves, in which the diameter of the passage is equal to the diameter of the pipeline itself. In full bore valves there is no resistance to the working medium, there are no pressure losses and no turbulence.

The main advantages of ball valves:

• no operating costs for maintenance and revisions;
• high flow shut-off speed and tightness;
• various connection options - welded, flanged, threaded and their combinations;
• small dimensions and weight;
• long period of trouble-free operation;

Areas of application for ball valves:

Ball valves are used both in main pipelines and in branches, to shut off working environments with high temperature and pressure.

Our company sells, classifying them by area of ​​application: , food industry, pipelines for petroleum products and some types of oils, pipelines for acid-containing products. Manufacturers of ball valves Naval, Vexve, Genebre, Broen have been on the pipeline fittings market for quite a long time, product quality and delivery times are justified by reasonable prices, all products are certified and comply with international standards.

Using its own production capabilities and developments, the Masterprom company offers its services for the automation of pipeline fittings - installation of electric drive equipment of imported and Russian production. To connect the electric drive and manually operated valves, special and so-called Masterprom productions are used.

It is also possible to lengthen the ball valve rod in cases where installing the electric drive directly on the valve is impossible. A series of rod extensions ШТН () allows you to adjust the height of the drive mounting point within +/- 500 mm, a series of rod extensions ШФН () has a fixed length from 500 to 3500 mm.

Currently, hot water supply is an integral part of the lives of most people on the planet. No apartment or residential building can live without it. Arranging a hot water supply system is a complex process; moreover, there are several types of connecting systems. In this article we will look at all hot water supply systems, calculations and types of water heaters.

Regardless of the type of hot water supply, a set of equipment is connected, which are designed to heat water and distribute it to various water intake points. In this equipment, water is heated to the required temperature, after which it is supplied into the house and through the pipeline using a pump. There are open and closed hot water supply systems.

Open system

An open hot water system is characterized by the presence of a coolant circulating in the system. Hot water comes directly from the central heating system. The quality of water from the tap and heating equipment is no different. The result is that people use coolant.

The open system is so named because hot water is supplied from the open taps of the heating system. The DHW scheme of a multi-storey building provides for the use of an open type. For private homes this type is too expensive.

You should know that the cost savings of an open system occur due to the no need for water heating devices to heat the liquid.

Features of open hot water supply

When installing an open hot water supply, the operating principle must be taken into account. There are two types of open hot water supply depending on the type of circulation and transportation of coolant to the radiators. There are open systems with natural circulation and those using pumping equipment for these purposes.

Natural circulation is carried out in this way: an open system eliminates the presence of excess pressure, so at the highest point it corresponds to atmospheric pressure, and at the lowest point it is slightly higher due to the hydrostatic action of the liquid column. Thanks to the low pressure, natural circulation of the coolant occurs.

The principle of natural circulation is quite simple, due to the different temperatures of the coolant and, accordingly, different densities and masses, cooled water with a low temperature and a larger mass displaces hot water with a smaller mass. This simply explains the existence of a gravity system, which is also called gravitational. The main advantage of such a system is absolute energy independence, if parallel heating boilers do not use electricity.

It is important to know! Gravity pipelines are made with a large slope and diameter.

If natural circulation is not possible, pumping equipment is used, which increases the rate of coolant flow through the pipeline and reduces the time it takes to warm up the room. The circulation pump moves the coolant at a speed of 0.3 - 0.7 m/s.

Advantages and disadvantages of an open system

Open hot water supply is still relevant, thanks primarily to energy independence and other advantages:

1. Easy to fill open hot water and vent. There is no need to control high pressure and bleed additional air, since the venting is carried out automatically when filling through an open expansion tank.
2. Easy to recharge. Because there is no need to monitor the maximum pressure. It is also possible to add water to the tank even with a bucket.
3. The system functions properly, regardless of leaks, since the operating pressure is not high and the presence of such problems does not affect it.

Among the disadvantages is the need to control the water level in the tank and its constant replenishment.

Closed hot water system

The closed system is based on the following principle: cold drinking water is taken from the central water supply and heated in an additional heat exchanger. After heating, it is supplied to water intake points.

A closed system implies separate operation of the coolant and hot water; it is also distinguished by the presence of a return and supply pipeline, which are used for circular circulation of water. Such a system will ensure normal pressure even when using a shower and sink at the same time. Among the advantages of the system, the ease of regulating the temperature of hot liquid is also noted.

DHW can be circulation or dead-end. A dead-end system consists only of water supply pipes, the method of connecting which is the same as in the first case.

The advantage of a closed hot water supply is the reduction of costs by ensuring a stable temperature. It is possible to install a heated towel rail. A closed hot water system requires water heaters, the types of which we will consider below.

Types of water heaters

All water heaters are classified as follows:

1. Flow devices. Such heaters heat water continuously, leaving no reserve. Since water has a high heat capacity, constant heating requires increased energy consumption. In addition to this factor, the flow-through heater must be immediately brought into working condition: when turned on, supply hot water, and when turned off, stop heating. Traditional flow-through heaters include a gas water heater.
2. Storage devices. They are characterized by slow heating of a certain volume of water, which often consumes 1 kW/hour. Hot liquid is used as needed. Storage heaters operate immediately after opening the tap, but the power is much less. Among the disadvantages of such devices, large sizes are also noted; the larger the volume, the larger the device.

Calculation and recirculation of hot water supply

The calculation of hot water supply systems depends on the following factors: the number of consumers, the approximate frequency of shower use, the number of bathrooms with hot water supply, some technical characteristics of plumbing equipment, and the required water temperature. By calculating all these indicators, you can determine the required daily volume of hot water.

Water recirculation in a hot water supply system ensures that liquid is returned from a distant water intake point. It is necessary when the distance from the heater to the farthest water intake point is more than 3 meters. Recirculation is used using a boiler, and if it is not possible to use it, it is started directly through the boiler.

The hot water supply system can be of two types, which are used depending on the specified parameters. An open system uses a heating boiler, and a closed system uses a water heater. In some cases, it is necessary to additionally organize water recycling. Before installing and purchasing equipment, it is important to calculate the hot water supply.

Our topic today is the hot water supply system of an apartment building: diagrams, main elements and typical problems that a homeowner may encounter. So let's get started.

DHW and heat supply diagram

The hot water supply scheme in an apartment building can be implemented in two fundamentally different ways:

1. It uses water from the cold water supply and heats it with heat from an autonomous source. This could be a boiler installed in the apartment, a gas water heater or a heat exchanger that uses coolant from a local boiler house or thermal power plant for heating;

Please note: the advantage of this scheme is higher water quality. It must comply with the requirements of GOST R 51232-98 (“Drinking water”). In addition, hot water supply parameters (temperature and pressure) extremely rarely deviate from nominal values; in particular, the DHW pressure is always equal to the cold water pressure, taking into account the pressure loss during water withdrawal.

1. It supplies water to the consumer directly from the heating main. This is exactly what is implemented in the vast majority of residential and administrative buildings of Soviet construction, constituting 90% of the housing stock in the vast expanses of our great and vast land. In the future we will focus our attention on it.

Dear reader can find additional information in the video in this article.

Elements

So, what elements does the water supply scheme of an apartment building include?

Water metering unit

He is responsible for supplying cold water to the house.

The water meter performs several functions:

• Provides accounting of water consumption (as its name clearly suggests);
• Allows you to turn off cold water to the entire house to repair shut-off valves or eliminate spillage leaks;
• Provides rough filtration of water at the entrance to the house. For this purpose, the water meter is equipped with a mud trap.

The water meter includes:

1. Inlet and house shut-off valves (valves or ball valves located on the input side of the cold water supply system and the in-house water supply system);
2. Water meter (usually mechanical);
3. Mud tank (a tank with a drain valve, in which, due to the slow movement of water through its volume, sand, large particles of rust and other debris settle). Often, instead of a mud pan, the water metering unit is equipped with a coarse filter, in which a stainless mesh is responsible for cleaning the water from debris;
4. Pressure gauge or control valve for its installation;
5. Optionally, the water meter can be equipped with a bypass line with its own valve or ball valve on it. The bypass opens when the water meter is dismantled for repairs or verification. At other times, it is closed and sealed by a representative of the water supplier organization.

It is curious: “Vodoset”, or the organization replacing it, is responsible for the state of the cold water supply input up to the first flange of the inlet valve. The water meter is the responsibility of the organization serving the house.

Elevator unit

The elevator unit, or heating point, also combines a number of functions:

• Responsible for the operation and regulation of the heating system;
• Provides the house with hot water. Water (also the coolant of the heating system) is supplied to the in-house hot water system directly from the heating main;
• Allows, if necessary, to switch DHW between the supply and return lines of the heating main. The switch is necessary because in winter the supply temperature can reach an impressive 150°C, and the permissible maximum hot water temperature is only 75°C.

A short lecture on physics: water is heated above its boiling point without evaporating, due to excess pressure in the heating main. The higher the pressure, the higher the boiling point of liquids.

The heart of the elevator unit is a water-jet elevator, through the nozzle of which hot and higher-pressure supply water is injected into a mixing chamber filled with return water. Thanks to the operation of the elevator, a large volume of water with a relatively low temperature passes through the heating system of the house; At the same time, the water consumption from the supply is relatively small.

DHW taps are located between the inlet valves and the elevator. There can be two of these inserts (one on the supply and return) or four (two on each thread). The first scheme is typical for houses built in the 70s of the last century and older buildings, the second - for more or less modern buildings.

Why are additional inserts needed?

To answer this question, we need to jump ahead and study water supply schemes in apartment buildings.

On cold water, a dead-end scheme is always used: the water meter goes to the only bottling, which goes to the risers, which end with in-house connections. Water moves in such a water supply circuit only when drawing water.

What's going on at the hot water supply?

In houses with two hot water connections into the elevator unit, the same scheme is used.

However, it has two rather annoying drawbacks:

1. If there has been no water supply through your riser for a long time, the water has to be drained for a long time before it heats up;

Please note: if your connections have mechanical meters, they will record water consumption, ignoring its temperature. As a result, you will end up overpaying a hundred or two rubles every month for a service that you didn’t actually use.

1. Towel dryers installed on hot water supply lines, which are also responsible for heating the bathroom, will only heat up when hot water is supplied to your apartment. And, accordingly, they will remain cold most of the time. Hence the cold and dampness in bathrooms, which often become the cause of fungus.

An elevator unit with four hot water connections ensures continuous circulation of hot water through two bottlings and risers connected by jumpers.

DHW operation is possible according to one of three schemes:

1. From the supply to the return pipeline. This scheme for hot water supply to a multi-storey building is used only in the summer, when the heating is turned off: a bypass between the lines of the heating main would reduce the pressure drop at the elevator;
2. From feed to feed. This scheme is for autumn and spring with their relatively low supply temperature;
3. From return to return. So the DHW is turned on during cold weather, when the supply temperature exceeds the threshold 75 degrees.

Readers who have not forgotten the basics of physics will have a reasonable question: how is the pressure difference necessary for continuous circulation between two tie-ins in one thread ensured?

Remember: water continuously moves through the pipes between the inlet valves and the elevator. To create a pressure difference, you only need to limit the flow by placing an obstacle between the taps. This role is played by a retaining washer - a metal pancake with a hole in it.

Captain Obviousness suggests: a significant restriction in the permeability of any pipeline would interfere with the operation of the elevator unit, therefore the diameter of the retaining washers is a millimeter larger than the diameter of the elevator nozzle. This, in turn, is calculated by the organization (heat supplier) in such a way that the return temperature at the outlet from the heating point corresponds to the temperature schedule.

Bottlings

Water supply bottlings are horizontal pipes running through the basement or subfloor of a house, connecting the risers with the elevator and water meter units. There is always one cold water dispensing, two domestic hot water dispensings in the hot water circulation system.

The bottling diameter, depending on its material and the number of water consumers, varies from 32 to 100 millimeters. The last meaning is clearly redundant; however, the water supply project for an apartment building had to take into account not only the current condition of the pipelines, but also their inevitable overgrowth with sediment and rust. After 20-25 years of operation, the pipe clearance in cold water decreases by 2-3 times.

Risers

Each riser is responsible for the vertical distribution of water in apartments located one above the other.

The most typical scheme is one group of risers (hot water supply and hot water supply, optional heated towel rails) per apartment; however, other options are possible:

• Two groups of risers can pass through the apartment, supplying water to the bathroom and kitchen located at a large distance;
• Risers in one apartment can supply water not only to its residents, but also to neighbors behind the wall;
• For hot water supply, circulation jumpers can connect up to 7 risers from several apartments.

The typical diameter of cold water and hot water risers is 25-40 mm. The diameter of the risers of heated towel rails and single (without plumbing fixtures) circulation risers is usually smaller: they are mounted with a DN20 pipe.

In the hot water circulation circuit, the jumpers between the risers can be located in the apartment on the top floor or placed in the attic. The jumpers are equipped with air vents (Maevsky valves or conventional valves), which allow the air that is obstructing circulation to be released.

Eyeliners

Their function is to distribute water to plumbing fixtures inside the apartment. What is useful to know about water supply connections?

• Their typical size (for steel water and gas pipes) is DN15 (which approximately corresponds to an internal diameter of 15 mm). When replacing hoses with your own hands, it is advisable not to reduce their internal diameter - this will lead to a drop in pressure on all plumbing fixtures when water is drawn from one of them;

• Since Soviet times, apartments have traditionally used simple and cheap serial (tee) wiring. A more material-intensive collector requires, among other things, hidden installation of connections, which greatly complicates their further maintenance;

• Over time, the throughput of steel connections drops noticeably, due to the notorious overgrowing of deposits. In such cases, the pipes are cleaned with a thin steel string or, simply, replaced with new ones.

If you decide to replace the liners, we strongly advise you to opt for metal pipes. The instruction is associated with a fairly high probability of water hammer and deviations from the standard temperature in the hot water system: for example, if a forgetful mechanic does not switch the water supply from supply to return during the first frost, the water temperature can significantly exceed the maximum for any polymer pipes of 90-95 degrees.

Which pipes can be used for water supply:

Image	Description
	have been used for water distribution since Stalin times. Unlike black steel, galvanized steel is resistant to deposits and rust. An important point: galvanizing is installed only on threaded connections, since during welding the zinc in the weld area completely evaporates.
	have long proven their reliability and durability: the oldest operating copper water pipes are more than a century old, and they are in excellent condition. Soldered connections of copper pipes are maintenance-free and can be mounted hidden, in a screed or grooves.
	Corrugated stainless steel pipes compare favorably with competitors due to their extremely simple installation. To connect them, compression fittings are used, the assembly of which requires only two adjustable wrenches. The service life of the pipes themselves is characterized by manufacturers as unlimited; however, after 30 years, you, or more likely your children, will need to replace the silicone O-rings in the fittings.

Malfunctions

What problems in the operation of the water supply system can the apartment owner eliminate on his own? Here are some of the most typical situations.

Valves leaking

Description: leakage along the stem of screw valves.

• Reason: partial wear of the oil seal or wear of the rubber O-ring.
• Solution: open the valve knob all the way. In this case, the thread on the rod will tighten the seal from below, and the leak will stop.

Crane noise

Description: when you open a hot or (less often) cold water tap, you hear a loud noise and feel the vibration of the mixer. Alternatively, your neighbors faucet could be the source of the noise.

Cause: a deformed and crushed gasket on the screw valve in the half-open position causes a continuous series of water hammers. Its valve closes the seat in the mixer body at intervals of a fraction of a second. In hot water, the pressure is usually noticeably higher, so the effect is more pronounced.

Solution:

1. Shut off the water to the apartment;
2. Turn out the problematic valve housing;
3. Replace the gasket with a new one;
4. Use scissors to remove the chamfer from the new gasket. The removed chamfer will prevent the valve from beating in a turbulent stream of water in the future.

By the way: ceramic faucets are fully compatible with screw threaded faucets, and do not have the described problem.

Cold heated towel rail

• Description: The heated towel rail in your bathroom has cooled down and is not heating up.
• Cause: if the water supply scheme of a residential apartment building uses continuous circulation of hot water, the air remaining in the jumper between the risers after water is discharged (for example, for inspection and repair of shut-off valves) is to blame.
• Solution: go up to the top floor and ask your neighbors to bleed the air from the jumper between the DHW risers and heated towel rails.

If for some reason this cannot be done, the problem can be solved from the basement:

1. Shut off the DHW riser passing through your apartment, to which your connections are connected;
2. Go up to the apartment and open the hot water taps all the way;
3. After all the air has come out of the riser through them, close the taps and open the tap on the riser.

A caveat: immediately after the end of the heating season, there may be no pressure difference between the threads of the heating main. In this case, the heated towel rails will be cold even if there are no air pockets in the risers.

Conclusion

We hope that our material helped you study the water supply of an apartment building: the water supply scheme described by us is the most common. Good luck!

A three-way mixing valve is designed to mix two incoming flows (cold and hot) into one outgoing flow at a given temperature. These valves are especially in demand in domestic hot water supply systems to protect consumers from scalding. They can also provide hot water directly from instantaneous or storage water heaters or be used as a preliminary mixing stage. They are no less often used to maintain a stable supply temperature in underfloor heating systems.

Principle of operation.

Internal regulation of the valves is carried out automatically due to the presence of a temperature-sensitive element, which is in contact with the mixed flow and contracts or expands depending on the deviation of the mixture temperature from the set output value, thereby increasing or decreasing the hot or cold water inlets.

How does burn protection work?

Most thermostatic valves currently on the market have a temperature protection device - “scald protection”. In the event of an unexpected interruption in the supply of cold water to the valve, the supply of hot water is automatically shut off, thereby eliminating the possibility of supplying hot water without prior mixing to the consumer.

Direction of flows.

There are two schemes for directing flows in a thermostatic valve - symmetrical and asymmetrical. The choice of a specific scheme depends on the type of installation and ease of installation in a particular heating or hot water system. Let's take a closer look at each of them.

GW- hot water;

HV- cold water;

NE- mixed water.

Symmetrical T-shaped flow direction diagram

Cold and hot water are supplied from opposite sides, mixing occurs in the middle. This scheme is very common in Europe, due to the compactness of the valves.

Asymmetrical L - shaped flow direction diagram

Hot water is supplied from the side, cold water is supplied from the bottom. It became widespread due to the versatility and simplicity of the resulting mixing unit.

Examples of the appearance of thermostatic valves with symmetrical and asymmetrical flow patterns:

	Watts AquaMix (Germany)	Danfoss TVM-H (Denmark)

It is thermostatic valves with an asymmetrical flow pattern that will be discussed further.

Application areas of thermostatic mixing three-way valves.

Housing and communal services / Management companies and homeowners associations

Who is responsible for the condition of the first hot and cold water tap from the riser? The owner of the apartment or the management company (HOA)? One way or another, every apartment owner has encountered these questions. The faucet is leaking, at whose expense is the replacement? The tap broke - who will pay for the damage? So, the Supreme Court of the Russian Federation in its decision states: the management company is responsible for the condition of the first crane riser.

Who is responsible for the first water tap in the apartment from the riser?

Hot and cold water in apartments of apartment buildings is supplied through the so-called “risers”. From them, through “branches”, intra-apartment wiring is carried out to points of consumption (sinks, bathtubs, toilets, etc.)

In this case, the risers are part of the common property and the management organization (HOA, management company, etc.) is responsible for them. And the owner of the apartment is responsible for “diversions”. The line of responsibility runs along the first tap after the riser. But who is responsible for the tap itself?

Current legislation interprets this point as follows:

In particular, clause 5 of the Rules for the maintenance of common property in an apartment building says:

... The common property includes in-house engineering cold and hot water supply systems, consisting of risers, branches from the risers to the first disconnecting device located on the branches from the risers, the specified disconnecting devices, collective (common house) cold and hot water metering devices, the first shut-off and control valves on the branches of the intra-apartment wiring from the risers, as well as mechanical, electrical, sanitary and other equipment located on these networks...

(Rules for maintaining common property in an apartment building, Clause 5)

It seems that everything is clear - the first taps from the riser are part of the common property of the house. However, in real life, utility workers act according to their own logic. Here is one of the stories.

An accident occurred in the apartment of a resident of Magadan - the tap on the cold water “comb” located at the outlet from the riser broke. Water flooded the apartment and spilled into the apartment on the floor below. The total amount of damage was more than 10,000 rubles.

The management company refused to voluntarily compensate for the damage. The owner of the apartment had to sue. The Magadan City Court satisfied the plaintiff's demands. However, utility companies challenged the decision in the regional court. They motivated their position by the fact that the owners of the apartment installed the ill-fated “comb” themselves, without complying with the technical requirements for this type of work. Accordingly, they are not responsible for the condition of the independently installed crane and are not required to compensate for the damage.

The Supreme Court of the Russian Federation put an end to the proceedings, where the owner of the apartment appealed. The Court's decision states:

... The first shut-off devices and shut-off and control valves on the branches of the intra-apartment wiring are elements of intra-house engineering systems designed to perform the functions of hot and cold water supply, gas supply, as well as the safety of the premises of an apartment building.

By ensuring the supply of utility resources from utility networks to intra-apartment equipment, these elements change the parameters and characteristics of intra-building engineering systems, thereby influencing the maintenance of other premises of the apartment building.

Taking into account these technical features, the first shut-off devices and shut-off and control valves meet the main characteristic of common property as intended to serve several or all rooms in the house. The fact that the specified equipment is located in the apartment does not mean that it is used exclusively for servicing this premises and cannot be classified as common.

Circumstances indicating that the emergency plumbing equipment belonged to the property of Bilenko S. Yu., or to the common property of the residents of the apartment building, were legally significant and subject to proof.

When considering the case, the appellate court referred to the fact that Bilenko SV. Along with the replacement and re-equipment of internal engineering networks, which are its property, the shut-off valve (shut-off and control valves) was replaced at the junction with the outlet from the common cold water supply riser, which caused the leak, and is the common property of the owners of the apartment building.

The plaintiff disputed these circumstances, but the appellate court did not check them and did not establish them for certain.

Simultaneously Replacing the shut-off valve does not relieve management organization - Zhilservice LLC from fulfilling its duties for the maintenance of the common property of an apartment building, assigned to the company by the concluded agreement...

Full text of the ruling of the panel of the Supreme Court of the Russian Federation in this case.