How to connect a pressure sewer to gravity. Pressurized sewerage device

If you ask people the question “what is a pressure sewer and what is it”, not everyone will be able to give the right answer. Of course, this knowledge is fully available only to qualified specialists, but there may be a situation when you need to know how the sewer system functions in the house. Below we consider what a pressure sewer is in a private house, get acquainted with its features, how it is arranged and how it functions.

General characteristics

Initially, it should be understood that there is a pressure sewer and gravity. Depending on the surrounding conditions, each system is installed with certain nuances. If, due to external conditions, it is not possible to equip a gravity system, a pressure system is used, which is characterized by certain advantages:

• Long operating period. Modern pipes for pressure sewerage are made of various materials, namely from cast iron, PE and PVC. Each type has its own characteristics and is considered strong enough for sewer systems;
• The pipeline will almost never clog. This is due to the work of modern pumps with cutting edges, the task of which is to grind the fabric and solids in the drains;
• A relatively economical solution if systems of small length and diameter are connected;
• Easy operation;
• Pipes and fittings of such a sewer are quickly connected. To install the sewage pumping station, large-scale earthworks will not be required. Similarly, if pressure pipelines are laid, running almost parallel to the ground;
• The compactness of household plumbing. Sewerage works from a pressure station, but due to its small size it can be installed even in the basement of a private house, which most often implies a typical project.

Here are the cases if a typical project is assumed in which the connection of a pressure sewer is actual:

• Pipelines for the release of internal sewage are located below the installation point, for example, if there is already a sewer system;
• The area in which the laying is carried out is characterized by significant differences;
• If the pipeline is connected in a closed way, for example, across the road;
• It is not possible to equip a deep trench due to the characteristics of the soil or for other reasons.

How is a pressurized sewer system

As the main element of the described system, KNS is used, that is, a sewer pressure station. The SPS collects all the effluents that are in the sewer country house. Due to the functioning of a powerful pump, all wastewater is transported to a place where it is further disposed of. This station functions as a drive, but only up to a certain point. If there are more drains than necessary, the pump starts its work.

Under the influence of pressure, the effluents begin to move through the pipeline (pressure collector), moving to the discharge point. The sewer collector is an automatic system that does not require the attention of the operator. Action may only be required if a problem is identified.

SPS is not the only element of the sewer. It provides separate pipelines. Some time ago, pressure and non-pressure sewers were assembled from steel pipes, which were produced specifically for such systems. Nowadays, cast iron and plastic products are used to assemble such systems. Pressure sewer pipes uPVC, however, are the most popular, as they are characterized by many advantages: they are affordable, easy to install and long lasting.

There are also combined systems where products made from a variety of materials are installed. For example, in the sewer, sealed-type products are mounted after the sewage pumping station, and before it, drains move through ordinary plastic pipes.

Note! To raise drains from the lower floors to the upper ones, in this situation it is required to use PVC pipes that are designed for such loads.

In addition, in order to raise drains from the lower level, the following scheme operates: a mini-sewer station is installed - a sololift. It is mounted behind the toilet. It is capable of not only transporting, but also crushing wastewater, since small-diameter products simply will not let them through. A mini sewer station must be connected to all plumbing fixtures that are on the floor.

Important! Connecting to such a system is not easy, and this will require special, high-quality equipment. You will also need to calculate the pressure sewer.

For your information. Often, when installing a pressure sewer, special check valves are used, thanks to which the drains cannot move down to the lower level by gravity, even if the pumping equipment is turned off.

What is a damper well

The sewerage pressure absorber is an important element of the entire system. It is very important to install it correctly so that living outside the city is comfortable and does not cause trouble. Such a well for extinguishing pressure is not a particularly complex design, so you can equip it with your own hands. The drawing is what you need to prepare by mounting the well yourself.

The role of the damper well is to slow down the movement of wastewater before it is diverted to the central sewer. Thus, the main system operates in a non-pressure mode.

Gravity sample systems are often found in areas where, due to the angle of inclination, effluents can flow under their own power directly into the settling tanks. Such systems are often found on long routes. This is a rare occurrence on the territory of country houses, because for the arrangement of a gravity sewer, pipes must be laid at a steep slope.

The solution to the problem is the installation of a pressure sewer, where its main equipment is a sewer pumping station.

It happens that it is difficult to choose a pump of the appropriate power so that it works normally with products of a certain diameter. In this case, wastewater can move at high speed. It depends, for the most part, on how much sewage is in the sewer.

The damper well is necessary in order to reduce the pressure in the system, the pressure force, as a result of which the load on the pipes is reduced, allowing them to last longer. The described well has the form of a cylindrical container with a bottom, to which pipes are connected at different levels.

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If you ask people “pressure sewage - what is it?” - only a few can give an answer. This is not surprising, since this knowledge is rarely useful to anyone other than builders. But still, there are situations in which it is necessary to know exactly how the sewer system works in the house - and here this knowledge will immediately pop up in memory. This article will talk about the pressure sewer and aspects of its design, operation and installation.

Why do we need a pressure sewer in a private house and what is it

So, pressure sewer - what is it, and why is it needed? In fact, a pressure sewer device is a structure consisting of sealed pipelines that ensure the movement of effluents to the place of their collection or treatment using pressure exerted by a powerful pump.

There are a number of cases in which drains cannot be allowed to flow by gravity, but must be forced to move through the system:

1. If the house is located lower than the central sewer is located - in a lowland or beam.
2. If the relief of the site at the place of the pipeline is uneven, and the drains too often stagnate along the way.
3. If the sewer pipeline can only be laid open method, for example, over the roadway.
4. If the trench for laying pipes cannot provide a sufficient slope for the independent movement of sewage. This often happens in built-up areas or where the soil has a rocky character.
5. If the sewerage system has to be installed from pipes of small diameter.

A sewer pumping station is often used to lift sewage from the lower floors of a building. For these purposes, combined sewerage systems are usually installed: the lower floors are a platform for the installation of pressure elements, and a traditional gravity system is installed above. As a result, all drains are reduced to one exit, from where they are moved to the collection point.

Of course, in order for the system to work correctly, it is necessary to perform a hydraulic calculation of the pressure sewer.

There are many options for mounting a similar design, and all of them have one indisputable advantage: even in the most inconvenient conditions, you can mount a combined system that will provide high-quality transportation of wastewater and will not be an invoice from a financial point of view. In any case, before arranging, you need to create a “pressure sewage” project, according to which the installation will be carried out.

Pressure sewerage device from pipes

The main element of the pressure sewer is the SPS (sewer pressure station). The sewage pumping station collects all drains located in the internal pipelines of the building. By the force of a powerful pump, waste is transported to the place of their disposal. The pumping station works like a storage tank, but only up to a certain level (more details: ""). When the amount of waste in the tank reaches the desired level, the pump starts.

The pressure acts on the effluents and transports them through sealed pipelines (pressure manifold) to the designated discharge point. The pressurized sewer is an automatic system, therefore no operator is required for its operation - it will be enough to react only in case of a malfunction.

In addition to the sewage pumping station, the system also uses several branch pipelines. In the past, pressure sewer steel pipes made specifically for such systems were used. Now pressure sewerage can be made of cast-iron or plastic pipes. Of course, PVC pipes for pressure sewerage are used more often, since they have a number of advantages: they are low cost, much easier to install and last longer.

In the creation of combined systems, pipes from various materials are usually used. For example, sealed pipes are installed in the network only after the sewer pumping station, and before it, the movement of effluents is carried out by ordinary plastic pipes. Of course, there is also an exception to this rule: for lifting waste from the lower floors, it is better to use PVC sewer pressure pipes designed for such tasks.

In the rise of wastewater from the lower levels, mini sewer stations - sololifts are used. They are installed right behind the toilet and perform not only the function of transporting waste, but also crush them, since small-diameter pipes cannot cope with large fractions. In addition, mini sewer stations will be connected to all plumbing fixtures located in the same bathroom.

Combined pressure sewerage is a rather complex structure with many branches and outlets, therefore, high-quality equipment is required for the system to work. In addition, you need to without fail carry out the calculation of pressure sewerage. Often, when arranging a pressure sewer, special check valves are used to prevent the flow of effluents by gravity down to the lower levels when the pump is already turned off.

Pros and cons of pressure sewerage

It is far from always necessary to use pressure sewage - the range of its application is very limited. But there are some moments when such a system is simply indispensable.

External pressure sewerage has the following advantages:

1. Low price. Of course, the equipment is not so cheap, but there is one caveat: when arranging a gravity system on a site with difficult terrain, you have to equip a large number of overflow wells. In addition, the slope of the pipeline will have to be observed, and for this, very deep trenches may be required for long distances. Pressure sewerage is devoid of this disadvantage, therefore, in such cases, its use becomes appropriate.
2. Savings on pipelines. The pressure system uses pipes of reduced diameter. To fully understand the importance of this indicator, it is enough to know the prices for 200 mm pipes used in gravity structures and 80 mm pipes used for arranging sewer systems.
3. Simplicity and speed of installation. Since the pressure sewer does not use a lot of trenches and overflow wells, the speed of construction of such a system will be much higher.
4. Long service life. Standard pipelines can last at least 50 years without any problems. Pumping stations usually have a 30-year warranty. Of course, problems can arise, and they do, but they are rarely critical: as a rule, minor mechanisms that can be easily repaired fail.

In addition to everything described above, it can be added that the pressure sewer is very rarely clogged, since the pressure exerted by the pump is large enough to independently eliminate any blockages and plugs that occur in the system.

The structure can also be equipped with an external pumping station- it all depends on how many bathrooms are installed in the building. Indoor stations process waste from one bathroom, but outdoor stations handle big amount drains. So for a small building, it is quite possible to use an indoor station with a small capacity.

Pressure sewerage has only one drawback, and an indirect one, which has already been mentioned: such a system is not needed in all cases, and if it is not necessary, then the installation of pressure sewerage will be useless.

Conclusion

Pressure sewage in a private house or in an apartment building is a fairly strong sewer equipment that allows you to solve a certain range of problems. The use of pressure sewerage will simplify the collection and transportation of waste in difficult conditions.

July 7, 2016
Specialization: master in the construction of plasterboard structures, finishing work and laying flooring. Installation of door and window blocks, facade finishing, installation of electrics, plumbing and heating - I can give detailed advice on all types of work.

If your site has a difficult terrain, the collector of the central network is far away, or non-fast elements of the system are located below ground level, then pressurized sewage will be the best solution. Its main advantage is independence from external conditions, you do not need to bother with the slope and lay the pipe too deep, the work process is simple, and the result is reliable. I will tell you how to make a system on your own, and consider the main advantages of this option.

Main stages of work

As for professional specialists, they create structures in accordance with SNiP 2.04.03-85 “Sewerage. External networks and structures”. Any deviations are fraught with a fine and even a ban on the use of communications, so I advise you to always consult with a professional in advance to find out exactly what requirements the supervisory authorities put forward and what factors are taken into account during checks.

Design

If you have definitely decided that you will implement the pressure option, then you need to start work precisely with the creation of the project. The efficiency of the future system and its reliability largely depend on this, as for the main factors that must be taken into account, they are as follows:

Type of system up to the sump	The fact is that the pressure system can be of two types: with a gravity pipeline to the settling well and with pressure supply in all parts of the communications. The choice depends on how your house is located relative to the collector. On my own behalf, I’ll say that the first option is much simpler, when drains from plumbing are supplied by gravity, therefore, if possible, choose it
terrain	In the vast majority of cases, pressure sewerage is used precisely in areas with difficult terrain. It is important to figure out in advance how to design the system so that the implementation of the project takes place with the least amount of time and money. Try to bypass the most difficult areas and minimize labor-intensive work
Soil features	Here I will include two factors, the first is the depth of soil freezing in your region, the pipe must lie below this mark, or communications must be additionally insulated with special materials. The second factor is the composition of the soil, this is especially important in mountainous areas and areas where many large stones come across. In this case, again, it is easier to lay the pipe at a shallow depth and carefully insulate it.
system configuration	Here I advise you to be guided by one phrase: maximum simplicity. That is, if there is an opportunity to simplify the project, then do it without hesitation. The fewer turns in the pipeline, the less the likelihood of blockages, and each change in direction in the external system requires the installation of a rotary well, which complicates the process and increases labor costs.
Equipment power	In pressure structures, a fecal pump with a chopper is mandatory (drainage pumps can also be used, but I strongly recommend this option). If the section from the house to the sump is also pressure-controlled, then one or more pumping stations will need to be installed inside. When choosing, you need to take into account the approximate volumes of wastewater and the distance at which they need to be pumped out, based on this, the optimal power is calculated
Pipe diameter	This factor is important for the pressure part. The fact is that for the system to self-clean, it is necessary that the minimum flow rate in the pipe during pumping be 0.7 m / s, if this figure is less, then deposits will accumulate on the walls. Most often one of three options is used: 40 mm, 50 mm and 63 mm

I also want to draw your attention to such a factor as the size of the sump, this indicator is important for situations when there are interruptions in the system.
For example, for a family of three, the minimum size of the sump is 1.8 cubic meters, which is enough to use the sewer for three days without any problems.

The project instructions are as follows:

• First you need to think about the location of all the elements. A sump and a quenching well require special attention, which must be present before entering the central sewer. Another important factor is the security zone of the system, wells should be located no closer than 50 meters from sources drinking water, the nearest body of water must be at least 100 meters (if it is a river, then 250 meters), as for the distance to buildings and other objects, they are indicated in the table below;

• Next, you need to decide on the features of the system: what type will be inside the building, what is the length of the pipelines and what equipment will be used. From myself I want to give this advice: try to make the length of the pressure head as small as possible, that is, if it is possible to place the sump closer to the central communications or septic tank, then do it. The shorter the length of the pipeline under pressure, the less the load on the equipment;

Many experts recommend not making a sump, but using a small pumping station that takes up little space and turns on when necessary.
I do not recommend this option, because if you do not have electricity, then the pump will not be able to pump out the drains, and you will be left without sewage, while with a large sump you can safely use the system.

• A project is drawn up that accurately reflects all the data: from the length of pipelines, their diameter and location to the exact characteristics of the equipment and its installation location. If you do not know how to draw up a sketch, then it is better to contact specialists, based on your data, they will do everything quickly, moreover, if an error has crept into your calculations, they will correct it and do everything as necessary.

To make everything clearer to you, I will consider the simplest version of the outer part of the system, in which effluents enter the sump through a gravity flow structure:

• The storage well (2) is located under the house (1), this option is convenient, but it can only be done if you have designed a similar structure before the construction of the building began. If work is carried out in an already built house, then the well is located nearby;

• The internal space of the receiving well is divided into two parts: a sump (2a) and a pumping compartment (2b). Even if you have a pump with a grinder (10) installed, then the presence of a sump will not be superfluous, especially since you just need to install a partition in the middle, and put a grid with a large mesh (9) in its upper part;
• Through the pipeline (6) they are fed into the well-quencher (3), which also functions as an inspection compartment. This element is needed in order to extinguish the speed of effluents, which are supplied quickly enough during pumping, because then they go through a gravity pipe (7) into the central sewer network (4). If you have a septic tank, then the system will be the same, just instead of a centralized sewer, the end point will be a septic tank or a sewage treatment system.

Preparatory stage

If the documentation is ready, then preparation work can begin, this is an important part of the process, on which the reliability of the system and its efficiency directly depend. A quality project assumes that the calculation of the required number of pipes and their diameters has already been made. The optimal characteristics of the equipment are also determined, you only need to purchase everything you need in order not to make a mistake when choosing, use a few simple recommendations:

• The best option for laying is PVC-U pressure sewer pipes, they are characterized by low weight, excellent resistance to adverse effects and a long service life. Cast iron options, which used to be the main ones, are almost never used in our time for the reason that the polymer pipe is no worse in terms of its performance, while its price is much lower;

• As for the pump, in one of the reviews I talked about the main options for equipment used for sewage, read it and you will understand what pumps are and what are the differences between each type. If you are too lazy to read, then I advise you to opt for a submersible fecal pump with a grinder in a stainless steel case. This is a very reliable and durable option that is easy to install and operate;

• If your project provides for a pressure system inside the house, then you will need to install one or more domestic pumping stations. They are located where the plumbing is located and allow you to quickly and efficiently drain waste into the sump. This option is very convenient, it is easy to install and maintain, in the diagram below I showed what such equipment looks like and where it can be located;

• As for the storage tank and the damper well, you can either make them yourself from well rings or buy them ready-made. Modern products are made of PVC or fiberglass and are lightweight, which simplifies their installation. At the same time, the reliability is very high.

Installation work

If everything you need is at hand, then you can proceed to the construction of the system. The process is simple and consists of several main stages, which are presented in the diagram. Each of them is described in more detail below:

• Work on laying systems in the house is considered in many reviews. Here I want to note only one thing - if the system is gravity-flowing, then there are no differences from the usual workflow. And if household sewer stations are used, then the easiest way is to place them behind the toilet in the toilet and under the sink in the kitchen, if the house is small, then you can limit yourself to one block;
• The storage tank must have sufficient volume so that in case of power outages and emergencies, the well can ensure the functioning of the sewer for at least 3 days. As for the material of manufacture, it may be a ready-made option, there may be concrete rings, or maybe red brick;

• The damper well can also be small in size, its main function is to slow down the flow before discharge into the central sewer or septic tank. Here it is worth remembering one simple rule: the incoming pipe is always located above the outlet. Speed ​​damping can be implemented due to the presence of a partition or by setting the knee at an angle of 90 degrees, these are the simplest options;

• If the section from the house to the drive is gravity-flowing, then when laying it, observe a slope of 2-3 cm per linear meter of the system. If all parts are pressure, then the slope is not necessary. As for the depth, it should be greater than the freezing point of the soil, if it is problematic to arrange the pipes in this way, then use a heater to protect communications from low temperatures;

• As for the installation of the pump, the list of works depends on which modification you have chosen. Most often, no additional preparation of the base is required, because the well should have a flat and solid bottom by default. The most important thing is to connect the pipes well and connect the system to the electrical network so that the danger of moisture ingress is excluded.

Pros and cons of a pressure system

Pressure sewer - what is it in terms of practicality? We will deal with the main advantages and disadvantages of the design, starting with the advantages:

• For proper operation of communications, it is not necessary to observe slopes towards drives or the central system. Moreover, drains can be supplied from the bottom up, which allows you to make high-quality sewage even in areas with difficult terrain;
• The small diameter of the pipes used simplifies the laying process. In addition, their cost is lower than that of large diameter options;
• Due to the fact that wastewater moves under pressure, and not by gravity, the likelihood of blockages is many times lower. It is important to make the right calculations so that the liquid moves at a certain speed, this allows you to wash away all solid particles;
• The level of plumbing elements in the building may be below the level of the sewer network.

Among the shortcomings, a couple of factors should be highlighted:

• If the electricity goes out, the pump will not work. That is why I advised to make the system to the drive gravity, if there is such an opportunity;
• In the event of a problem, you will have to go down into the well to disconnect the pump. That is why it is better not to save money and purchase reliable equipment.

Conclusion

Pressure sewerage in a private house is an excellent solution in case of difficult terrain or when the central system is located at a great distance from the house. The video in this article will talk about some important points in more detail, and if you have a question on the topic, then ask it in the comments.

July 7, 2016

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Pressure sewerage ensures uninterrupted transportation of wastewater to the treatment plant, minimal excavation during the manufacture of trenches. Instead of 150, 110 mm pipes are most often used pipelines 50 mm which saves the construction budget. Clogging of sites occurs much less frequently, since the self-cleaning ability of the flow increases. Pressure pumps can be placed inside the house or in the intake manifold at the exit from the dwelling. In the first case, they are installed after each plumbing fixture or pump the drains of a group of fixtures in a separate room.

Internal pressure sewerage

The main pump manufacturers are:

• Jemix
• Grundfos
• Cachenc
• Pedrollo
• Rise LLC

Internal pressure sewerage allows you to not comply pipeline slope, therefore, the quality of concealed pipe wiring increases. The advantages are: silent operation, minimal maintenance, self-connection by consumers, reduction of blockages. Pressure sewerage is the only one possible when equipping basements and socles of dwellings with plumbing. In addition, it is widely used in difficult terrain (a septic tank is above the level of the outlet knee internal system), the presence of existing highways on the site.

The pump has effluent storage tank, uses intermittent operation. The grinder is built into the body, so that the faeces are transported without clogging the pipeline. Equipment of this type is selected according to its characteristics, and is produced in ergonomic cases that do not require additional masking. Compact pumps fit easily into base cabinets under sinks, space behind toilets, maintenance-free.

External pressure sewerage

Outdoor manifold appropriate when creating a gravity system inside the house, but, the impossibility of moving gray, black drains into a septic tank in the same way. Contaminated liquid is collected in a collector near the house, pumped from it by a pressure sewer to a treatment plant semi-submersible, surface, submersible pump. The collector is buried slightly for ease of maintenance from the ground, additionally insulated with mineral wool, extruded polystyrene foam. Modern pumping stations use short-term pumping modes when a certain level is reached, which allows to reduce energy consumption.

Pressure sewerage is installed at the site improvement stage, the industry produces collector covers that can be integrated into any landscape design without violating the aesthetics of perception. In the outdoor household. The system cannot be connected to storm water, drainage, bath, pond, pool drains in order to avoid overflow treatment plant. For each of the listed

nalizatsiya uses an independent collector, reservoir.

The type of sewerage is determined at the planning stage, taking into account the GWL, the depth of the septic tank, the presence engineering systems that crosses the highway of the external system, the presence of plumbing in the basement. This reduces construction costs, provides comfortable use of household plumbing.

With a weak absorbency of the soil, the impossibility of discharging wastewater treated by a septic tank into the ground through wells / filtration fields, another pressure line is added that moves the purified water for reuse (irrigation, cleaning the territory, washing vehicles, filling the bath tank). In this case, the pump is installed at the outlet of the septic tank / aerotank, and is used to move liquid to ground tanks.

When organizing an autonomous sewer system in a private house, as a rule, a non-pressure scheme is used, in which the movement of drains occurs by gravity. But in some situations, such an implementation is not possible. Difficult terrain, hard ground and other reasons can create the necessary pipe slope. The only solution in such cases is the connection of a pressure sewer (hereinafter referred to as NK). We will talk about its principle of operation and implementation features, which will allow us to use this information as a guide for those who are going to assemble such a circuit with their own hands.

In this type of drainage, the movement of wastewater is carried out using a special pump, and not under the influence of gravity, as in gravity systems. This allows you to organize the supply Wastewater to the outlet, if it is located above the zero point.

Pumping units (stations) are an important unit of pressure water disposal, depending on their functional purpose, they can be:

• Intra-house designed to service individual buildings. Such installations are a sealed container equipped with a pump and a grinder. The small dimensions of the device allow it to be installed in the basement of the building. Below is a drawing depicting the main structural elements of the Sololift station.

Figure 2. The main elements of the pumping sewer station for a private house Sololift

Designations:

• A - Top cover with carbon filter.
• B - outlet tube with check valve, which plays the role of a valve when the vacuum pump is turned off. Insertion into a common riser is allowed.
• C - grinder.
• D - inlet cleaning filter.
• E - pumping mechanism.
• F - tank.

– Outdoor KNS serving several residential buildings at once. In this case, drains (including storm water) are discharged by gravity from several sections into a common tank, from where they are pumped into a central collector or treatment plant.

An example is the equipment of Wavin, Rehau, Evac, etc.

Strengths and weaknesses of pressure systems

Let's start with the advantages of NC, these include:

• Lack of strict requirements for the angle of rotation, pipe inclination and installation of revisions.
• The sewage pumping stations are equipped with shredders, which makes it possible to reduce the diameter of the pipes without the risk of blockage.
• Due to the pressure created, the pipeline is self-cleaning.
• The absence of tilt requirements allows you to place sanitary equipment anywhere.

This drainage system also has significant drawbacks, the main one being dependence on power supply. If it is turned off, there is a high probability of clogging, so it is recommended to install the UPS as a backup power source.

The negative side also includes the high cost of equipment and the cost of its regular preventive maintenance.

Validity of application

In most cases, when organizing local system sewerage for a private house uses a gravity flow scheme, as it is more economical and easy to maintain. But in some situations, the installation of NK is not only justified, but also has no alternative. The basis for making a decision in favor of installing a sewage pumping station may be:

• difficult terrain, which does not allow to provide a constant slope necessary for the organization of a gravity system;
• the presence of rocky or moving soil, which complicates or makes it impossible to lay the pipeline at the estimated depth.
• the large length of the pipeline route, which excludes the creation of conditions for the gravity movement of water.
• the drainage point is located below the inlet, an illustrative example is shown in the figure below.

In the figure, the nodes are marked in red, where the installation of a toilet pump or other plumbing equipment is required.

Please note that the transfer of the toilet in the apartment, as a rule, is not possible without appropriate repair and plumbing work. To avoid this, you need a household low-power SPS, such as the Sololift in Figure 2.

Design

If there are enough grounds for the arrangement of the NC, you can proceed to the first stage of construction - the design of the system. This part of the work is best left to the experts. They will perform the calculation of the sewage pumping station, determine the optimal pump power and the need to install a switching chamber, draw up an accurate estimate and an explanatory note and comply with design standards. An example of such a project and installation estimates can be found on thematic sites and forums.

Note that when connecting to the central sewerage networks, the operation service will first of all request a draft drainage system. When organizing an autonomous NK, some of the problems are removed, but, nevertheless, there are nuances that must be taken into account.

Errors in hydraulic calculation, calculations of minimum pipe diameter, engine power, etc. may lead to unstable operation of the internal or external network of the NC. In some cases, the situation can be corrected by creating a pressure damping loop (damping well).

The number of such wells in the system is not standardized, their number, the distance between the two nearest ones and the characteristics are determined in the course of calculations or according to the results of a hydraulic test. It is not as serious as for the oil pipeline, but, nevertheless, it must be carried out for oil companies without fail.

Choosing a fecal pump

First of all, it is necessary to determine its capacity, it depends on the length of the vertical and horizontal pipeline lines. This dependence is shown in the figure below.

As for the flow rate in the NK system, according to the SNiP standards, it should be about 2.0 l / s, respectively, the pump capacity is selected at the level of 120 l / min. Next, you should decide on the type of pumping equipment, it can be:

• Submersible (suction).
• Superficial.

The first are more expensive, they are designed for trouble-free operation in an aggressive environment. The latter are somewhat cheaper and easier to maintain, but their installation will require more effort.

Tank volume

The calculation of the volume is based on the daily rate of water consumption per person, its average value is about 0.20 m 3. The tank must contain a minimum of three-day flow. For example, if 4 people live in a building, the average daily consumption will be about 0.80 m 3, taking into account the three-day norm, the tank should have a volume of at least 3.20 m 3.

It is advisable to dwell on the two-chamber design of the tank, in this case one compartment will play the role of a primary settling tank, and the second one will play the role of a pumping chamber. It is in it that a fecal pump equipped with a grinder will be installed. The filling of the tank is controlled by special sensors, when the threshold level is reached, the pump is started to pump them out.

You can purchase a ready-made sewage pumping station with a plastic tank or build a storage tank yourself from concrete rings or brick and install the necessary equipment.

Choosing a place for a storage tank

In order to avoid claims from the water utility, the sanitary and epidemiological service and other regulatory organizations, the choice of the location of the storage tank should be taken seriously. In accordance with the norms of SNiP 020402-84, a sanitary protection zone must exist around a possible source of pollution. The above document specifies the minimum distance that should be between the pipes (sleeves) of the NK and wells or other sources of drinking water. These SNiPs also regulate the distance from the security zone of residential buildings, site boundaries, shrubs and trees, as well as other objects.

In addition, underground utilities passing through the site should be taken into account, unfortunately, their designation on the drawings is not always present, which can cause certain difficulties. Information about the availability of such communications can be obtained from the relevant services.

What pipes are better to make NK?

Since the operating pump creates pressure drops in the system, the pipes and fittings involved in it must have:

• sufficient flexibility;
• strength in places of fastenings and joints;
• resistance to frequent pressure changes.

These conditions are met by cast-iron socket and plastic pipes. The former have sufficient strength and performance characteristics, as well as a fairly long service life (25-30 years). But cast iron products have a number of significant drawbacks:

• heavy weight (complicates installation and repair work);
• the material becomes brittle in frost, which requires mandatory pipe insulation if the laying depth is above the soil freezing horizon;
• laborious connection technology.

These shortcomings have led to the fact that pipes made of this material are practically not used when laying sewer systems.

Plastic (PVC) and polyethylene pipes (HDPE) are the best option for organizing external and internal drains. Their main advantages:

• light weight;
• pipe material is not exposed to aggressive environment;
• simple connection technology;
• no deposits build up on the inside, reducing clogs and the need to use a plunger to clean out.

As an example of such products, we can cite the products of Ostendorf, Chemkor, Geberit, these pipes fully comply with GOST standards.

Please note that non-pressure sewer pipes designed for gravity systems inside and outside the building are not suitable for NK. The joints of such products will not be able to withstand pressure changes inside the system, which will lead to the formation of leaks.

The connection of plastic pipes in the NDT system is carried out using a special soldering station. Description of soldering technology can be found on our website. Note that there is also Alternative option connection with glue, it can only be applied to special glue pipes.

Briefly about laying pipes

There are two options for laying pipes for the outer part of the NK:

1. In the classical open way (a trench of a certain depth is dug, where pipes are installed, after which they are buried).
2. The method of horizontal directional drilling (HDD).

In the first case, you will have to face large-scale earthworks, but since you can do it on your own, you can reduce the cost of the project. With the second option, the laying speed will increase significantly, but special equipment will be required. Prices in this case will depend on whether two pipes are laid or one, the distance between two points, the complexity of the soil, etc.

As for the depth of the drain pipeline, it should be below the soil freezing horizon. If for a number of reasons it is not possible to fulfill this condition, pipe insulation will be required (information on this can be found on our website).