Modern water supply and heating systems cannot be imagined without filters. These devices purify water from dirt, corrosion products and sludge ( fig. 1), harmful substances and even microorganisms. And it doesn’t matter whether it is a cottage or an apartment in a high-rise building, a centralized or autonomous heat and water supply cannot be dispensed with. The market offers a wide variety of different filters, but in this article the most common and irreplaceable filters will be considered. rough cleaning   water. Among plumbers, these devices are called mud collectors or the abbreviated abbreviation "FGO".

Fig. 1. All this could get into the apartment system

According to the principle of operation, the coarse filters are mechanical, because their work does not require chemicals. In Soviet times, filters of this type were installed, as a rule, only on house inputs. In recent years, the requirements for the quality of water and coolant have increased, as buildings began to be saturated with instruments and fittings, which were very sensitive to pollution of the working environment. In addition, the condition of external engineering networks is deteriorating every year. More than 50% of engineering networks in Russia require replacement, and about 15% are in disrepair. A significant “contribution” to the pollution of pipelines is made by the specific “technology” of emergency repairs, after which already polluted lines are replenished with sand and garbage. All these factors require the use of CSF on water supply systems in each individual apartment.

The absence of a filter at the entrance to the apartment can accelerate the failure of water meters and household appliances (washing machines and dishwashers), as well as reduce the effectiveness of filters fine cleaning. The building codes currently in force (SP 30.13330.2012 “Internal water supply and sewerage of buildings”) regulate the mandatory installation of mechanical or magnetic-mechanical filters in front of water meters.

The degree of purification of the CSF depends on the design of the filter element. The smaller the size of its cell, the higher the degree of purification, but the greater the hydraulic resistance will create a filter. In this regard, the selection of the filter is best entrusted to a specialist.

The largest manufacturer and supplier of engineering plumbing in the Russian market and the entire post-Soviet space - the company VALTEC - offers a wide range of coarse filters for home networks.

The most requested CSFs are this. They have a simple design and are the cheapest of the filters. VALTEC offers several options for oblique filters, differing in the design of the threaded nozzles and dimensions ( fig. 2):

• VT.192 - filter with internal thread from 1/2 to 2 ";
• VT.191 - filter with external thread at the inlet and internal thread at the exit 1/2 ";
• VT.190 - filter with external thread 1/2 ".

Fig. 2. Oblique coarse filters (from left to right): VT.192, VT.191, VT.190.

All models of VALTEC oblique filters can be used in piping systems with a maximum working fluid temperature of up to 150 ° C. The filtering capacity for models up to 1 "in diameter is 500 microns. The filter consists of ( fig. 3) from the case 1   (hot-pressed nickel-plated brass CW617N), brass plugs 2 filter element 3   (AISI 316 stainless steel) and Teflon gaskets 4 . The filter plug has a sealing hole required when installing this element in front of the water meter. Servicing oblique CSF consists in periodically cleaning the filter element. To do this, unscrew the plug and remove the filter element for cleaning and flushing.

Fig. 3. VALTEC oblique filter design

An example of the use of the VT.190 oblique filter is given in fig. 4.

Fig. 4. The oblique filter VT.190 at the apartment water inlet

In addition to oblique filters, the VALTEC “arsenal” has several models of direct CSF ( fig. 5):

• VT.385 - compact straight filter having a plug with 1/2 "thread;
• VT.387 - direct filter with external and internal thread;
• VT.388 - direct filter with internal thread.

Fig. 5. Direct coarse filters VALTEC (from left to right): VT.385, VT.387, VT.388

The design is such that the flow of the working medium at the entrance to the filter element rotates 90 °, creating a turbulent vortex washing the grid ( fig. 6. This contributes to a more efficient cleaning, preventing the growth of colloidal and fibrous particles on the grid. In the process of cleaning, the entire area of \u200b\u200bthe filter element is simultaneously involved. VALTEC direct filters are equipped with filter elements with mesh sizes of 300 microns, which is optimal for protection against clogging of apartment pressure reducers, water meters, thermostats, mixers and other water fittings.

Fig. 6. Design and principle of operation of direct filters

Instead of a cork, a drain valve (1/2 ") can be installed on the filter, which simplifies the washing process.

For ease of maintenance on models VT.387 and 388, plugs with internal thread are used. Due to this and the presence of a sealing ring made of EPDM, the plug thread does not come into contact with water and does not stick to the filter housing.

Direct filters can be used on pipelines with a working fluid pressure of up to 16 bar and a temperature of up to 110 ° C. Filters are available with nominal diameters of 1/2 and 3/4 ". Not always existing wiring of plumbing systems allows the use of standard products. When it is necessary to install a TSF on a vertical pipeline with water supply from the bottom up, ordinary oblique and straight filters are not applicable, because this leads to clogging of the lower pipe outlet ( fig. 7).

Fig. 7. Direct and oblique filters in a vertical section with the movement of water from bottom to top (error)

In such cases, it is necessary to make a horizontal section of the pipeline with the installation of CSF on it. However, not always the workspace allows you to do this. VT.386 (patent No. 2464479) comes to the rescue. At this filter, the axis of the filter chamber is rotated 75 ° with respect to the axis of the pipeline. Due to this, insoluble particles, scale and other contaminants are not able to fall back into the pipe, drop down when the flow stops, and remain in the filter chamber ( fig. 8).

Fig. 8. Appearance, design and operation of the VT.386 filter in a vertical section with bottom-up movement of water

Everyone is familiar with the situation when, after repair work or a short shutdown of the pipeline, brown muddy liquid flows from the mixer ( fig. 9) If you pour this liquid into a bottle, after a short period of time, you will notice that the upper part of the liquid in the bottle becomes transparent, and a dark precipitate accumulates in the bottom. The reaction of the precipitate to the presented magnet proves that it is iron hydroxides, in everyday life called “rust”. Rust particles are so small that they are able to freely pass even through filters with mesh sizes of 100 and 50 microns.

Fig. 9. The smallest particles of rust are not detained by the usual filter

Tachometric water meters suffer the most from rust. Getting into the impeller of a water meter, rust particles are attracted to a magnet built into the axis of the impeller ( fig. 10), which transfers rotation to the counting mechanism. The growth of particles leads to a slowdown in the rotation of the impeller, and then to a complete stop of the device. For manufacturers, this phenomenon is not a guarantee case, and the consumer is forced to pay for the purchase of a new meter.

Fig. 10. Rust destroys vane water meters

VALTEC specialists, realizing the urgent need to solve this problem, have proposed a simple but effective solution. VT.384 ( fig. eleven) It is a direct filter with the inherent advantages of this type of CSF, and a permanent magnet pressed into the plug allows trapping magnetic substances (metal particles, scale, etc.) much smaller than the mesh of the filter mesh (300 μm).

Fig. 11. The design of the filter with a magnetic catcher VT.384

To service the filter, it is necessary to unscrew the plug with the internal thread, clean the mesh filter element, flask and remove the formed metal "coat" from the bar magnet.

Flushing filters are becoming increasingly popular in residential water systems. They allow you to clean the filter without turning it off and disassembling it. Flushing VT.389 ( fig. 12) is equipped with two stainless steel filter elements (one in the other) with a mesh size of 1000 and 250 microns, a pressure gauge for monitoring pressure and a drainage valve for flushing.

Fig. 12. Appearance and design of the cascade filter VT.389

The filter housing and flask are made of nickel-plated brass grade CW617N. The presence of two filter elements of different capacity and the formation of vortex turbulence provides step-by-step cleaning and increases the frequency of filter maintenance. Currently, the VT.389 washing filter is available in three sizes: 1/2, 3/4 and 1 ". The uniqueness of the filter, in comparison with analogs, is its minimal dimensions with high cleaning characteristics (patent RU 111451 U1). Mount the washing filter Before and after the filter, shut-off valves must be installed to remove the filter elements. The best way to flush the filter is to backwash, but to implement it, you will need to install an additional section of the bypass pipeline.

Despite the fact that all CSFs are quite simple in design, this does not negate the requirements for their competent installation and operation. The most common errors of installers are the following:

• the flow direction of the medium does not coincide with the direction indicated by the arrow on the filter housing. Such an error leads to the fact that the sludge does not accumulate in the filter chamber, but outside it;
• the filter is installed with a stopper or plug up. With this installation, the sludge does not settle in the filter chamber ( fig. 14), but remains in the pipeline to the filter, which can disable the water shutoff valves located in front of the filter;
• an oblique or direct filter is installed in a vertical section of the pipeline with an upward flow without the device of a horizontal section. In this case, the sludge settling in the lower branch of the pipeline can eventually completely block the pipeline ( fig. fifteen).

Fig. 14. Installation error: the filter is installed upside down

Fig. 15. Installation error: oblique filters in a vertical section with an upward flow

Whatever the consumer chooses, the main thing is that this device meets the requirements and features of a particular system, and during installation and operation the building codes, rules and recommendations of the manufacturer are observed. Only in this case, the CSF will serve faithfully for more than a decade.

Sumps are a type of filter that is widely used in industrial production. Currently, water treatment plays an important role, so there is a need to install such filters - cleaners. They clean from lake and river water pollution in the form of sand, stones, soil, rust.

The sumps installed in the water supply and heating systems are filters that clean the clogs in the system. Metal particles and other foreign objects mix with water and clog the pipeline. This leads to a narrowing of the pipeline, reduce its internal diameter, which can cause contamination of the boiler and increase the likelihood of an accident. To prevent a decrease in the efficiency of the equipment and reduce the cost of maintaining the heating system to extend the life of the system, the water must be filtered.

There are several types of mud collectors.

Magnetic sump cleans liquids from metallic impurities. The principle of its operation is to catch metal particles from water and accumulate them in a sump. The pressure of the water flow is not violated. Magnetic filters do not affect the pressure in the system; therefore, they are used for pump operation.

Strainers clean the liquid by entering the pipe, where foreign particles precipitate in the form of sediment at the bottom of the internal cavity. After that, purified water is supplied to the heating system. The accumulated sediment is cleaned by removing the beaker from the nozzle. After washing the glass, it is returned to the nozzle.

Mud collectors are mounted taking into account convenient access and their maintenance. Install products at inputs to buildings.

Considering the installation method, construction and fastening of the sump can be divided into 3 types:

· Vertical

· Horizontal

· Subscriber

The cost of magnetic filters is higher than conventional strainers, because they are much more efficient in maintaining a water supply system.

Sump vertical st. (ZMZ) flange for water heating systems, Ru-10 T-150 vd.
Name	Weight, kg.	price, rub.
Mud sump vertical (ZMZ) Ru-10 Du-40, pcs	13,300	2 376,00
Mud sump vertical (ZMZ) Ru-10 Du-50, pcs	23,200	3 267,00
Mud sump vertical (ZMZ) Ru-10 Du-65, pcs	33,700	4 752,00
Mud sump vertical (ZMZ) Ru-10 Du-80, pcs	36,800	5 049,00
Mud sump vertical (ZMZ) Ru-10 Du-100, pcs	51,200	7 920,00
Mud sump vertical (ZMZ) Ru-10 Du-125, pcs	57,100	8 415,00
Mud sump vertical (ZMZ) Ru-10 Du-150, pcs	78,400	10 080,00
Mud sump vertical (ZMZ) Ru-10 Du-200, pcs	136,600	17 496,00
Mud sump vertical (ZMZ) Ru-10 Du-250, pcs	207,000	31 104,00
Mud sump vertical (ZMZ) Ru-10 Du-300, pcs	312,000	47 304,00

Gryazevik vertical steel fl. for systems water heating, Ru-10 T-150 (vd)
Sump vertical DU-40, pcs	17,000	1 650,70
Sump vertical DU-50, pcs	19,000	2 162,50
Sump vertical DU-65, pcs	29,000	2 998,70
Sump vertical DU-80, pcs	22,000	3 537,50
Sump vertical DU-100, pcs	26,000	5 162,50
Gryazevik vertical Du-125, pcs	72,000	5 875,80
Sump vertical DU-150, pcs	80,000	7 637,40
Sump vertical DU-200, pcs	125,000	12 980,30
Sump vertical DU-250, pcs	284,000	27 819,00

Unfortunately, the water entering the house from a well or central unit contains a significant amount of harmful substances that can harm the health of the body. These can be substances of mechanical, chemical and biological origin. Different types of filters are used to remove them. IN sump filters   the water is filtered by a metal mesh; the parameters with which the filtration will be carried out depend on the size of the cells. All grids are removable, made taking into account the possibility of replacing or cleaning the filter. Mud Filters   used to purify water from especially large impurities.

Mud Filters are installed at the point of connection of water from the house, strictly in front of the water meter (if any). All this is due to the need to protect the existing plumbing, household equipment and appliances that are connected to the water supply from "dirty" water.

When buying a coarse filter, you need to know that the device can tolerate significant temperature changes well enough. Undoubtedly, the ability to purify water is maintained even under the condition of a sharp pressure drop. The filter element in the coarse filters are mesh with small holes, the size of which ranges from 20 to 500 microns.

Mud Filterswhich are completed with the crane for cleaning in a water supply system are self-cleaning. This type of filter, complete with a pressure gauge, shows the pressure level in the water supply system. Operating pressure from three to five atmospheres (0.3-0.5MPa). When self-cleaning is not possible, cleaning is carried out by mechanical removal of the filter and subsequent cleaning of the mesh.

Water filter with pressure gauge   - This is a device that measures the level of water pressure, and there is a tap for dumping (filtered) sediment. Most models of this type are popular due to the significantly higher level of water purification compared to simple angle filters. The result is achieved through thin filter holes.

A small drawback is that water filter with pressure gauge   It has an impressive size compared to other filters and is relatively difficult to install, due to the need to connect the outlet of the wash filter with the sewage system.

Sump filters   serve to clean water preventing the ingress of large mud elements into the mixer or counter. The most common filters are: straight (perpendicular) and oblique. The water supplied to the filter passes inside the sump to the tubular mesh, passing through the walls of the filter is directed to the other side. All large solid-state inclusions do not exit, remaining inside the mesh. Which can be removed, washed or cleaned and reinstalled.

Because sump filterssince they do not have a very fine mesh, the passage of sludge or other fine dirt is freely carried out. However, this level of filtration is more than enough to protect the counters and ceramic elements of the mixers. SanComf is a site of high-quality sanitary equipment, offers you a wide range of water filters.

The heating system consists of many mandatory units, each of which performs its own specific functions. One of these elements is a mud filter for water, which is used to clean the coolant from foreign particles. This simple device has a significant impact on the efficiency of the heating system. This is especially noticeable in complex systems with a large number of control valves.

What does the installation of mud collectors for the heating system give?

With the need to install mud filters for water in centralized heating systems, no questions arise. Where the coolant is periodically drained and the system is refilled, it is impossible to argue with the obligation of this element in the system - there will always be dirt and impurities.

The neglect of the mud collectors begins with the independent design of small autonomous systems. For example, heating systems of a private house. It only seems that in a closed loop of small size, there is nowhere to get foreign impurities in the coolant from.

Whatever type of coolant is used, and no matter what initial cleaning it is subjected to, it will still be based on water. Water, which begins to interact with the metal nodes of the system, and metal is in any system. As a result of this interaction, rust particles circulate in the system. In some parts of the system (irregularities inside the pipes, weld flows, sharp turns, narrow passages, etc.), these particles accumulate, which impedes the movement of the coolant.

Since the intensity of the coolant circulation decreases, in order to achieve the required parameters of the temperature regime in the room, it is necessary to increase its temperature. This increases the load on the boiler and all other elements of the system, which does not add to them reliability, efficiency and effectiveness. Proper installation of mud collectors in the system eliminates most of these problems, or at least pushes the time of their occurrence.

Mud classification

The principle of operation is to pass the coolant through a special mesh or magnetic filter, sift the mud fractions and deposit them at the bottom of the glass. The main condition for proper operation is the installation of a sump in the direction of flow of the coolant.

Classification of sumps for heating systems is made according to several criteria. According to the degree of cleaning, fine and rough cleaning devices are distinguished. According to mounting options: threaded, flanged and welded. By the method of service:

• self-washing - the sediment from the sump and is washed off from the surface of the mesh by a stream of water when opening the crane on the mud sump;
• flushing - the cup is washed without removing the filter, but manually;
• non-flushing - for cleaning, it is required to dismantle and disassemble the assembly.

Filter Classification

Strainers. The most common and familiar type of sump filter for water used in everyday life. In the simplest design, dirt is trapped by the net and settles in the accumulation zone. Periodically, the bottom of the glass turns away and the dirt is removed. The design can be supplemented by a drain valve installed instead of the bottom, and then the sump from the wash becomes a self-wash.

The installation of an additional mesh that removes air from the coolant, the float and the needle valve adds to the mudguard the function of protection against gas contamination. The effectiveness of the mesh sump depends on the pressure in the line before and after it. With a significant difference in these values, solid particles can be forced through the grid.

Magnetic filter   removes metal particles from the coolant stream. During the operation of such a filter, no inhibitory effect on the fluid flow occurs, which is important during the operation of powerful pumps.

There are also inertial-gravitational and subscriber mud collectors. The principle of operation of the former is clear from their name and they are applied at large enterprises. Subscriber devices clean the coolant at the entrance to metering stations.

Features of the use of mud

All dirt filters for heating systems can also be divided into those designed for vertical or horizontal installation. Vertical structures are more often used in large heating systems. It should also be remembered that vertically mounted sumps need to be serviced more often. The selection of sizes and cleaning parameters is based on the diameters of the pipelines, the capacity of the pumps and the installation locations.

During installation, there are several rules that must be followed.

1. Arrow on the body. As a rule, the filter has an arrow indicating the direction of movement of the coolant.
2. The best location is a horizontal section of the pipeline.
3. Spatial orientation. The branch with a net and a nut or a drain cock should face down.
4. The presence of shutoff valves before and after the sump filter for water, as well as a pressure reducer after it.
5. Convenience of service.

Where in the heating system are dirt collectors installed?

1. Before metering devices, if any. Counters are classified as precision instruments and are extremely sensitive to contamination.
2. In front of boiler heat exchangers.
3. On circulation and make-up pipelines.
4. In front of dampers, sensors and other system elements as necessary.

Mud service in the heating system

Sumps are cleaned at least twice a year - before and at the end of the heating season. The frequency largely depends on the size of the system, the intensity of the coolant recharge and the degree of its preliminary cleaning.

In most cases, maintenance of household dirt filters can be done independently. It is enough to block the lines, unscrew the glass stopper, remove and wash the filter mesh.

Equipping heating systems with mud filters allows you to protect expensive system components, reduce the frequency of flushing and replacement of the coolant, and, consequently, operating costs.

Any heating system, whether central or completely autonomous, is a rather complex "organism", including many elements, each of which fulfills one or another purpose. And in this list of components must definitely find a place for devices for filtering and cleaning the coolant. This function is assumed by the mud collectors.

When designing central heating systems, such filters are planned without fail, both in boiler rooms or at thermal stations, and in collectors and elevator units directly in buildings connected to heating systems. But in individual construction, no, no, and there are situations where inexperienced homeowners do not fully understand how important mud filters are for heating systems, and do not include them in an independently developed scheme. And it’s completely in vain - these suckers are inexpensive, simple to install and maintain, the devices can significantly improve the operation of the entire system, significantly extend the trouble-free period of its operation, save the owners from the rather laborious and dirty work of periodically cleaning and washing pipes and radiators, and significantly reduce operating costs by housing heating.

The carrier of thermal energy from the boiler or central to radiators is the liquid coolant. Most often, this role is played by water, pure or with any chemical additives. Under certain conditions, for example, in private houses where the owners do not live year-round, special fluids that are resistant to freezing temperatures - antifreeze, are often used, but even in them water occupies a significant part of the total volume.

Water is always a very active oxidizing agent, causing corrosion of metal parts of heat traces, house wiring, radiators, shut-off and control valves. The resulting rust particles peel off from the walls over time and are picked up by the flow. However, if certain conditions are created in the pipe, on the tap, in the radiator, on the connecting welded or threaded joint, in the tee or on the turn (narrowing of the passage, unevenness, influx from the weld, changing the direction of flow, etc.), then this a place with a high degree of probability becomes vulnerable to the formation of a cork - small particles of scale settle, accumulate, layer, narrowing, and sometimes completely blocking the passage to the coolant.

Many probably know the situation when heating radiators are heated unevenly, not over their entire area. It also happens that in the battery several sections remain cold at all - the coolant through them clearly does not circulate.

Clogged sections of radiators - the reason for their uneven heating

If the check shows that there is no air in the radiator, then a similar picture can only be caused by the accumulation of dirt.

Sometimes when opening the battery you can see a similar "sad" picture

Such radiators will not be able to provide the required heat transfer, and you will have to resort to emergency measures - remove them and conduct a thorough rinse. And this, believe me, is a very complex and time-consuming process.

Clogged pipes - this is an additional, completely unnecessary load on the pump and boiler, nobody needs energy costs

So, narrowed passages do not provide the necessary volume of coolant circulation, and in order to achieve the desired temperature, it is necessary to increase the current boiler operation power. Moreover, the plaque layer on the walls of pipes and radiators becomes a “heat-insulating gasket”, that is, heat transfer is sharply reduced. And this is another reason for the increase in heating costs.

This "migrating" dirt and solid particles can lead to additional load on the circulation pump, damage to its turbine and complete failure. Well, the saddest thing is if blockages form in the heat exchanger of the boiler - in most cases this leads to burnout of the heat exchanger, often entailing the replacement of all expensive equipment as a whole.

An increased concentration of solid inclusions can seriously change the electrolytic characteristics of the coolant, which is extremely undesirable for heating systems operating from an electrode (ion) boiler.

• Heating radiators that are clean from dirt and solid deposits give maximum heat transfer, and free channels of pipes, fittings, connecting units and control fittings give the minimum hydraulic resistance of the coolant. Both that and another allows a copper and the pump to work optimally with the minimum consumption of the corresponding energy carriers. Moreover, it is estimated that, in general, the effect of saving the operation of a “clean” system, as compared to having mud layers, can reach even 40%.

In a word, there is something to think about - installing a relatively inexpensive and easy-to-use device immediately gives owners a lot of preferences.

The main types of dirt filters and their device

General classification of mechanical filters

In the filters coarse mechanical cleaning   water from solid impurities (which deserved the name mud collectors) three basic principles of separation of suspensions are used:

• Gravity forces are used in settling filters - due to a sharp increase in volume and, correspondingly, a drop in flow velocity, solid particles settle to the bottom under the influence of gravity. Often this is also supplemented by a sharp change in the direction of motion - then turbulent and centrifugal forces are also included in the “work”, which carry out more inert heavy particles to the periphery of the stream, where they settle, thereby freeing up water.

A typical device of such a sump is shown in the diagram below:

Usually this is a vertically arranged cylindrical body (pos. 1), in which two pipes with flange connections are welded in: inlet (pos. 2) and outlet (pos. 3). The bottom of the casing is closed by a flange plug (pos. 4), the top is tightly welded. The bottom plug usually has a pipe (pos. 5) for mounting a crane to it for carrying out maintenance work - draining sludge and washing the filter. At the top there is also a branch pipe (pos. 6) - a crane is installed here to discharge air when the system is filled with coolant.

One or more jumpers (pos. 7) can stand in the cavity of the central cylinder, which sharply change the direction of the flow of water passing through the filter (shown by blue arrows). Solid inclusions (pos. 8) settle down, where a layer of sludge forms (pos. 9), which is regularly cleaned during prophylaxis.

Such filters, as a rule, are installed in large pipelines, for example, in industrial enterprises. In a home heating system, their use is not very rational. However, the principle of gravitational water treatment has been successfully used in other filter models.

• Strainers - in them a stream of water is passed through a mesh structure with cells of a certain size. All particles whose diameter exceeds the cell size remain in the filter.

• In magnetic filters, as the name implies, permanent magnets are installed that attract small particles of metal and metal scale to themselves. It is recognized that the installation of a magnetic filter, in addition, dramatically reduces the likelihood of scale formation on pipe walls and in heat exchangers of heating devices.

As already mentioned, very often in modern mud filters used for heating systems, two, and sometimes all three principles of mechanical water treatment are combined.

According to the type of installation in the system, mud filters can be in three different versions:

• On pipes of small and medium diameter, characteristic of autonomous heating systems, clutch filters are often installed.

On both sides of such a product, couplings with internal (there are models with external) threads are provided for connecting to pipes. On the filter housing, respectively, hexagons are provided for inserting an open-end, adjustable or gas wrench during installation or disassembly. Such filters are usually immediately “packed” into the system when it is assembled.

• It is extremely difficult to work with threaded joints on pipes of medium and large diameters (over 2 inches), so filters with a flange connection are most often installed in such areas.

A flange connection involves the installation of an o-ring, and then tightening with bolts. At the initial installation of such a filter, there are a few more concerns, since it is necessary to weld the counter flanges on the pipe in a strictly installed position, observing the installation length of the product. But if it is necessary to remove the filter, it will be quite simple to do this without resorting to dismantling the entire wiring section.

• There are filters that are mounted to the pipes "tightly" - on both sides of such devices there are nozzles, along the edge of which a chamfer is started - for the weld.

Probably the only advantage of such filters is a lower cost. But in the event of an accident or the need for replacement, you will have to cut a pipe section.

Filters in a polypropylene casing, specially designed for similar pipes of small diameter, can also be referred to as fixed, welded sumps.

They also weld immediately when installing the pipe wiring, and to replace them, if necessary, you will have to cut out a whole section. Therefore, probably, they do not use special popularity - usually most masters prefer to install metal couplings, and only then switch to polypropylene from them.

By the method of maintenance, filters also have their own gradation:

• Self-washing - in such sumps a tap is provided in the lower part, at the opening of which accumulated dirt (sludge) is washed out by a stream of water. At the same time, the filter mesh is cleaned.

For better washing of the mesh, a bypass with a valve is often provided when installing the filter. This makes it possible to redirect the flow of water from the reverse side during maintenance — even the solid inclusions that are firmly stuck in the cells are so washed and drained very well into the drainage tap.

• Washing filters. They do not require dismantling the entire product - after disconnecting the system section from the coolant supply, it is enough to unscrew the plug or remove the flange plug, remove the filter element and clean and rinse it (if necessary, or in models with cartridge inserts, replace it with a new one). Then the filter is assembled in the reverse order - and it is ready for use again.

• There is also a category of non-flushing mud filters. To service them, you have to completely dismantle the entire device from the system. Of course, this is very inconvenient, and such products are not in demand and practically are not installed in autonomous heating systems.

And finally, mechanical filtration devices can be divided into two categories according to the degree of purification of the liquid passing through them:

• Coarse filters, which, in principle, are called "mud collectors", have grids capable of retaining solids larger than 300 microns (0.3 mm) in size.
• Fine filters are designed to filter out suspensions from 5 to 300 microns in size. They are usually used in systems for the purification of tap water for domestic and food needs. Such filters are not used in the heating system - such a high cleaning is not required here, and the filter elements themselves will quickly clog and require replacement or washing.

Now consider the most common varieties of dirt filters that are installed in heating systems.

Brass mesh “oblique” filters

This is perhaps the most common category of dirt filters used in local heating systems at home. They have a coupling threaded connection   in a fairly wide size range - from ½ to 2 inches, which is quite enough for installation on any autonomous heating pipeline.

The design of the filter is quite simple:

The device brass "oblique" mud filter

The cast brass body (pos. 1) is a monolithic conjugation of two cylinders, direct and inclined (pos. 3). On both sides of the straight cylinder there are threaded couplings for filter mounting (pos. 2). The “oblique” cylinder ends with a brass plug (pos. 4) with a turnkey hexagon. Between the stopper and the body there is a sealing gasket, usually Teflon (pos. 5). In the most inclined part there is a filter element - a stainless steel mesh (pos. 6) with cells of a certain size.

The correct direction of the flow of the filtered fluid is indicated on the casing with an arrow. The slanted part always looks forward in the direction of flow.

The tables below show the main operational and installation parameters of brass “oblique” filters:

The main operational characteristics of brass "oblique" filters:

Product Parameters	Pipe diameter
	G ½	G ¾	G 1	G 1¼	G 1½	G 2
Nominal pressure in the system, bar	20	20	20	16	16	16
Pressure test bar	30	30	30	24	24	24
The mesh cell size, microns	500	500	500	800	800	1000
The distance between the centers of the mesh cells, mm	1,1	1,1	1,1	1,4	1,4	1,6
Density of mesh cells per 1 cm², pcs	156	156	156	83	83	59
Maximum permissible coolant temperature, ° С	+150
The degree of transparency ("transparency") of the filter,%	39	39	39	53	53	59
Total filtration surface area with a clean mesh, cm²	17,9	32,6	44,8	55,7	77,1	111,0
The average throughput of the device with a clean filter element, m³ / hour	3,15	5,0	9,9	15,5	24,0	28,5
Nominal coolant flow with a clean filter, m³ / h	1,41	2,24	4,43	6,93	10,7	12,7
Average filter life	up to 30 years

Installation characteristics of filters:

Nominal bore, DN, mm	Pipe thread diameter	Building dimensions		Empty weight, kg
		height N, mm	length L mm
15	G ½	40.5	51	0.132
20	G ¾	47.5	63.5	0.213
25	G 1	53	68	0.285
32	G 1¼	65	91.5	0.573
40	G 1½	73	102.5	0.750
50	G 2	88	126	1.160

Installation of such filters is not difficult for those who are familiar with the basics of plumbing techniques. Typically, a shut-off valve is installed in front of the filter - it allows you to shut off the coolant supply for preventive maintenance to clean the device of accumulated dirt. But the main thing that is important to consider is the correct orientation of the filter in space:

Correct installation		Incorrect installation
	Proper installation in a horizontal area. The beveled cylinder is located below.		Such an arrangement in a vertical section from the coolant currents up does not allow the filtered sludge to concentrate in the cleaning chamber for prophylaxis. The cleaning capabilities of the device are sharply reduced, and dirt can collect on the walls of pipes or on valves.

Installation of the filter, as a rule, is carried out on the return pipe before circulation pump   or boiler, if the pump is structurally part of the boiler. Thus, all possible contaminants collected along the heating circuit are removed from the coolant that described the full circulation cycle.

Regular cleaning of the “oblique” filter is not particularly difficult. It is necessary to simply shut off the coolant supply taps on both sides (if a non-return valve is installed behind the filter along the liquid flow, then it can only be closed from the inlet side). Then, a container is supplied from below to collect leaking fluid and accumulated sludge. The cork is unscrewed with a wrench, the net is removed.

Mesh "oblique" mud sump, densely clogged with sludge

The mesh should be cleaned with a polymer brush and then thoroughly rinsed with a strong pressure of water. The glass of the “oblique” cylinder is checked - there should also be no deposits there. Then reassemble with tightening the cork. At the same time, it is possible to assess the state of the gasket, since over time it may require replacement.

Video: device and the process of cleaning the "oblique" filter

When purchasing such a filter, caution should be exercised. All the advantages mentioned in the table are valid only for high-quality brass products (some may have an external shiny nickel-plated or oxidized coating). Unfortunately, there are a lot of cheap fakes on the market made of silumin alloys, and no one will undertake to guarantee the long-term operation of such a filter.

Cast iron “oblique” magnetic filters

Externally, these filters are very similar to the brass ones discussed above and in general, they rub their device. The difference is in the material of manufacture: the body and cork are cast from cast iron. The filter element is the same cylindrical stainless steel mesh. The gasket between the cork and the body is usually paronite.

Cast iron "oblique" mud sump with a magnetic block

However, the filtering unit is supplemented by another element. A rack is rigidly mounted along the axis of the cork, on which disk-shaped permanent magnets of corrosion-resistant material are located at a certain interval. Thus, the filtration takes place in two directions - the grid captures mechanical impurities, and the magnetic block - metal particles and scale. The quality of cleaning the coolant from this only wins.

The main characteristics of the manufactured cast-iron “oblique” magnetic filters:

Nominal bore, DN, mm	Pipe thread diameter	Construction height mm		Construction length mm		Turnkey hexagon size, S, mm	The mesh size of the metal mesh, mm
		N	H1	L	L1
25	G 1	80	140	120	200	32	1,2x1,2
32	G 1¼	100	155	140	220	46	1,4x1,4
40	G 1½	110	180	160	280	46

Please note that in the columns of the mounting dimensions, two values \u200b\u200bof length and height are indicated. L and H are the usual mounting values, and L1 and H1 are subject to the mandatory provision of the necessary space for the free extraction of the plug with the stand and magnets during maintenance work.

Otherwise, the order of installation of such filters in the system and the cleaning process do not differ from similar operations with oblique brass. At the same time, the rack with magnetic disks is also subjected to cleaning and washing.

Flanged Magnetic Dirt Filters

Such filters almost completely repeat the cast iron “oblique” principle of operation - the difference is only in size. On pipes from G 2 and above, flange devices are usually installed.

Instead of a threaded plug, there is also a flange-type plug. It often has a place for a drain hole, closed by a stopper, which allows the sludge to be drained and flushed from time to time without resorting to removing the entire plug.

Characteristics of flanged magnetic filters

Nominal bore, DN, mm	Construction dimensions of products				The diameter of the hole for the flange bolt, d, mm	The number of holes for the bolt on the flange, n, pcs	Mesh cell size, mm
	height mm		length mm
	N	H1	L	L1
50	140	200	230	280	18	4	1,4x1,4
65	165	250	290	355	18	4
80	195	275	310	385	18	8
100	215	315	350	425	18	8
150	320	490	480	645	22	8	2x2
200	415	630	650	890	22	12

When installing such filters, the installation length and height (L and H) and operating (L1 and H1) are also taken into account, taking into account the place for removing the plug and removing the mesh and magnetic block.

Subscriber filters mud sumps

Among the most common filters installed on heat mains, in particular, on the areas of their connection to intra-house networks, are the so-called subscriber filters. They can be issued in vertical or horizontal execution, but vertical meets much more often. Such devices combine the functions of a sump and strainer filtering the liquid passed through them.

Such mud filters are called “subscriber”

Such devices have a very high operational resource, are easy to maintain, and their solid internal volume reduces the frequency of regular preventive maintenance.

Structurally, they are a cylindrical body made of steel pipe (item 1). On both sides, pipes with a flange are welded into it - inlet (pos. 2) and exhaust (pos. 3). The nominal diameter of the nozzles corresponds to the pipe into which the filter cuts.

The exhaust pipe has a special design. It reaches a length approximately of the central axis of the cylindrical body, and is muffled from the inside. In the segment from the wall to the plug, holes with a diameter of 5 to 8 mm were drilled in its walls, so that their total area was not less than twice the cross-sectional area of \u200b\u200bthe nozzle. A filter mesh (item 3) with cells of the appropriate size is laid on top of these holes.

A flange is welded along the lower edge of the pipe body to which the bottom cap is fastened with bolts (item 5). Typically, the plug allows for the installation of a drain cock (key 6) to regularly clean the cavity of accumulated dirt.

The filter cover is welded tightly, but it has a pipe or hole for mounting an air vent valve (key 7).

Characteristics of the line of vertical subscriber mud filters

Nominal bore, DN, mm	Mounting dimensions		Empty weight, kg
	height H mm	length L mm
40	217	308	16.7
50	240	359	22.7
65	369	419	45
80	369	419	48.9
100	421	473	70
125	421	473	73
150	563	526	103.3
200	669	626	184
250	785	730	269

The coolant passing through a similar filter goes through two stages of cleaning. Large and medium particles precipitate under the influence of gravitational and centrifugal forces, while smaller ones are already held on the grid.

Due to the simplicity and reliability of the design, the relatively low cost of production, the high operational potential, such subscriber filters are widely used in house wiring of heating systems. In particular, they are a mandatory element of the elevator unit.

Typically, the housing of such a filter is a metal cylinder (pos. 1), with a sleeve connection to the inlet (pos. 2) and outlet (pos. 3) nozzles. A glass (pos. 6) is screwed to it from below to collect sludge (pos. 7) - it can also be metal or plastic, including, on some models, transparent, which allows visual monitoring of the state of the filter. At the bottom, the glass ends with a tap (key 8) for cleaning and flushing the device.

Grids are installed inside the central part of the body. One of them, external, larger (item 4), acts as a separator of air and other gases dissolved in water. On it there is an accumulation and growth of bubbles, which then, upon reaching a certain size, independently rise up under the influence of gravity.

The fine mesh inner mesh (key 5) is used to filter out particulate matter from the coolant.

On top of the casing, a block for collecting separated air (pos. 9) is screwed with an automatic exhaust system. The valve design includes a float (key 10) connected by an actuating lever (key 11) to a needle valve (key 12). With the accumulation of air in the block, the float drops lower and reaches a certain level, through the lever opens the needle valve. Air escapes through the openings in the cover (key 13), the float rises again, and the valve closes.

The procedure for cleaning such filters from sludge has already been mentioned in the publication - just open the tap from the bottom and wash the dirt with a stream of water. It is even better if the possibility of creating a reverse fluid flow is provided for cleaning.

Some filters of this type are additionally equipped with magnetic inserts, which increases the cleaning efficiency. In addition, many models have built-in pressure gauges showing the fluid pressure at the inlet and outlet of the filter. A simple comparison of the readings of these devices can give a very clear picture of the degree of clogging of the filter elements with sludge (with a clean filter, the readings should be approximately equal), that is, signal the need for prevention.