Slope of sewerage in the apartment. The correct slope of sewerage: calculation

Lay sewer pipes as you like can not, for the simple reason that a private house uses a gravity sewage system. That is, the used water and impurities drain into the treatment facilities independently under the influence of gravity.

These systems have special requirements. One of them is the angle of the pipes. If the bias is made small, the water will stagnate in the pipe, which will lead to a clogging. With a large slope, the fluid drains faster than heavy fractions, which will settle and accumulate on the walls of the pipeline.

In addition, a strong angle leads to noise from the sewer pipes during the descent of water. Therefore, in order for the sewerage to work without failures, it is necessary to correctly calculate the slope of the pipes.

Calculation of slope

The minimum slope of the pipe, in which the sewerage will work effectively, can be calculated by the formula: U = L × Y. Where U is the slope, L is the pipe length, and Y is the minimum slope.

Imagine that:

• L = 5 m
• Y = 0.07

Then: U = 5 × 0.07 = 0.35 m.

The optimal difference between the beginning and the end of the pipeline length of 5 meters is 35 cm.

The construction of the sewage system is determined by building codes and regulations (SNiP) and must be taken into account at the design stage of the house. In accordance with SNiP, the optimal slope of sewer pipes with a diameter (Ø) of 50 mm is 3 cm per 1 running meter. For pipes Ø 100 mm, the slope is 2 cm.

The table below shows the main values ​​of the external sewerage angle based on SNiP 2.04.03-85 (paragraph 2.41) and SNiP 2.04.01-85 (paragraph 18.2)

Standards of external sewerage

The optimal bias for can not be exceeded unnecessarily. The diameter of the external drainage is greater than the internal one, therefore, with an increase in the angle of inclination, heavy fractions will settle on the walls and create a congestion.

A pipe with a cross section of 150 mm is laid with a drop of 0.8 cm per 1 meter. With a diameter of 200 mm, the difference will be less - 0.7 cm. The maximum slope that can be made is 15 cm per meter.

Tilt device for installation

For pipes of the following materials are used:

1. cast iron;
2. asbestos;
3. plastic.

Depth of the pipeline depends on the climatic conditions of the region and varies from 0.5 m to 2 m. The trench digs 20 cm deeper than the planned level, to level and create a sand cushion.

To set the right angle, you need to drive the pegs and pull the string at the beginning and end of the ditch. With the help of a tight twine, you can even out the bottom and set the desired angle. At the bottom pour sand layer of 10 cm.

Additional requirements

• For the pipes of external sewage, the rules provide for a number of additional requirements:
• The maximum slope is 15 cm / m, except for pipeline sections shorter than 1.5 m;
• The bottom of the trenches should be solid, without stones and sharp inclusions. A cushion of sand is obligatory, it should contain sand and fine gravel of a fraction of 20 mm. The thickness of the pillow is from 10 to 20 cm;
• The distance from the walls of the ditch to the edge of the pipe is 20 - 30 cm on each side;
• The sewage pipes are laid below the freezing level of the soil, if they can not fulfill this requirement.

Construction manuals offer two methods for calculating: using the formula (described above) and tabular. The table below shows the average values ​​for pipes of different diameters.

From all of the above it turns out that the optimal slope in the network of external sewage is from 1.5 to 2 cm per 1 running meter, depending on the diameter of the pipe and material. For proper operation of the entire system, it is necessary to follow the installation and operation rules.

Video: the slope of sewerage and their methods of exposure

Working on the project of a system of a house drain, it is necessary to know, on how many degrees it is necessary to tilt a sewer pipe. With the external simplicity of the design, improper installation of the pipe can lead to undesirable consequences and the work will have to be done anew. In most cases, the sewerage in the houses runs by gravity, so it becomes obvious that a too small angle will result in insufficient passage, and in the opposite case the system will not work.

Beginning builders often want to install a pipe under a big slope, so that impurities pass through it faster, however, this approach is erroneous. If the slope is excessive, the pipe begins to silt because the water leaves very quickly and does not have time to wash all the impurities that subsequently stick to the sewer system from the inside. Also, for this reason, the water locks in the siphons are broken, which can cause air from the cleaning system to enter the living room. Probably, it is not necessary to explain which smell emit impurities.

There is one more reason why the pipe should be left under-filled. The influx of air in corrosive environments increases the development of corrosion, which reduces the service life of the system.
  The main problem faced by inexperienced builders trying to independently run a drainage system is that the slope is measured in unusual units. In the building rules and norms, in all other reference books for builders, decimal fractions are indicated, for example, 0.03 or 0.0012.

Most people are more likely to measure the slope in degrees, so they can not understand the significance of these figures. However, everything is quite simple. This fraction means the ratio of the height of the drop in the pipe to its length. It is best to track it in centimeters. For example, 2 cm by 70 cm or 1.5 cm by 70 cm. The length of the sewer pipe, measured in meters, after multiplying by the amount of slope, will give the total height of the slope throughout its duration.

We will explain with an example. Let's say that the total length of the pipe is 5.6 meters, the reference requires a decrease of 0.07, in which case there should be a difference between the level of the end and the beginning of the pipe of 5.6 * 0.07 = 0.39 or 39 cm.

The main parameter, which should be guided when laying the pipe for sewage, is its fullness. This figure can be determined by dividing the height of the water level in the pipe by the diameter of the sewer pipe. If this value is 0, then the pipe is completely empty, and if it is 1, it is clogged. The optimal value for this indicator is the range from 0.5 to 0.6. It is in this case that the runoff works fine.

A small spread is associated with the different properties of the pipe making materials and their ability to form a boundary layer that is held near the inner surface of the pipe. For example, pipes made of plastic or glass have a smooth surface, their filling should ideally be 0.5, and the pipes made of asbestos and ceramics have a rough terrain, so the optimum value for them is 0.6.

This filling value allows the passage of effluents at a rate of 0.7 meters per second, which keeps the solid fractions suspended and prevents them from adhering to the walls of the pipe.
  So, the design characteristics of the sewer pipe can be determined by multiplying the speed by the square root of the pipe occupancy. This value should be greater than or equal to the optimal level of occupancy (0.5 - 0.6).

The minimum slope of the pipeline in an apartment depends on the diameter of the pipes. According to the handbook, for pipes with a diameter of 50 mm, it is 0.03, which means 3 cm per meter, and for 100- or 85-mm pipes - 2 cm.
  How, after all, is it possible to calculate the slope of the pipe for sewage and not make a mistake? Often, the floors in apartments and private homes can not be called absolutely smooth, so it is desirable to use the laser or bubble level.

A tensioned rope can also help. When connecting a pipe to the riser, it can be used to determine the reference vertical. In order to calculate, the amount by which the sewer pipe will converge with the riser, it is necessary to calculate the arcsine of the ratio of the drop and subtract this result from 90.

In the rules and norms of construction, the optimal dimensions of the slope of the external sewage pipeline are indicated, which have a larger diameter than internal communications. With a pipe diameter of 150 mm, the slope of the meter / meter of the pipe should be 0.008, and in special conditions 0.007. In the 200 mm pipe version, the slope of the meter / meter is 0.007, and under special conditions 0.005.

Special conditions are such conditions when, for various reasons, it is not possible to create the required bias, in other words, the special conditions indicator assumes a minimum level of decline if something prevents to create the optimal slope for the external sewerage pipe.

There is also the largest value of this parameter. It equals 0.15, which means that if you decrease by more than 15 centimeters for each meter of the pipeline, the system will work very inefficiently, the pipe will be flooded with water as it quickly converges and quickly clogged with sewage. The liquid simply will not have time to wash away the solid impurities.

Counting the bias, you can take into account other features of the system, for example, the nature of its load.  If the drain is to be made from the washstand in the apartment, then do not be afraid of flooding, and, if necessary, the slope can be made quite large, but still so that the probability of breaking water locks in siphons is excluded.

Compliance with the technology of laying the sewerage line, as well as the sizes recommended by the standards, are the bases of trouble-free operation of the system. Do not think about how to choose the optimal slope of the pipe, just open the SNiP and there find the answers to all the questions.

Summarizing the above, it is worth to conclude that the most optimal value of reducing the pipe for sewage is in the range of 15-25 mm per meter of pipe, and the exact data can be found in the reference books.

Slope of sewage pipe 110 mm

The main reference, which should be used in determining the slope of sewer pipes, is SNiP. It says that for pipes with a diameter of 110 mm, the optimum inclination angle is 0.02. However, it is worth remembering about other nuances. When installing pipes, it is recommended that you avoid turning at a right angle in any plane.

In order to avoid this, it is worthwhile to use a serial connection of several taps with a small angle. If there is no such possibility, then it is possible to establish audits (cleansing) in such places. All parts of the sewage system must be firmly secured with special clamps, the step of their installation is equal to 10 pipe diameters.

The internal sewage drain must be equipped with fan ventilation, which will protect the room from getting into it unpleasant odors, and also ensure the correct operation of the system without the breakage of the water closures.

The fan pipe must be installed vertically without deflection. In a private house sometimes you have to mount horizontal sections, then they should be done with a slight inclination. In this case, the slope of the fan pipe is directed towards the system. This is done to ensure that the atmospheric condensate and precipitates trapped in the pipe immediately flow into the sewage system and do not block the pipe.

To install an external 110-mm sewer pipe, a minimum slope of 0.03 should be followed. When installing an external system, you need to use different rules. The sewage line should be laid 30 cm below the freezing level of the soil. Otherwise, there will be a need for special thermal insulation. Ditch should be 20-30 cm deeper than the level of laying pipes, and if it is deeper, it is necessary to fill it with a mixture of sand and earth followed by ramming.

Adjust the level of the ditch conveniently with a thread stretched to the desired level. The last bed under the pipe and the slope of the sewer is formed by a sand cushion on which the system is mounted. Pipes for sewage need to be mounted by the bell to meet the flow, which will ensure a high level of tightness.

If you want to shorten the pipe, then it can be cut with an ordinary hacksaw and chamfer at the edge of the cut. The trumpet should not be truncated. All material used in the pipeline must be free of chips, cracks and breaks, otherwise the system will be silted. In the places of turns of the line and level differences, special wells are installed. After assembling and laying pipes, you need to check their level. If necessary, sand bed can be poured, so that it covers the pipe by a third. Pipes should lie rigidly, without the formation of voids below them. Only in this case will optimal sewage slopes be formed.

After adjustment, the pipe falls asleep, and initially it is done with sand to prevent damage to the system by clods of earth. Then you can continue to fill the trench with technology.

It is impossible to work on laying pipes according to the principle of "how it works", because in most houses a gravity drainage system is equipped. It is capricious: if the incline is insufficient, the sewage pipes will soon be clogged. A too large deviation of sewerage by 1 meter will increase noise and cause leaks. These problems will entail the need to clean the system, which is problematic.

For the reason that in the runoff waters there may be fats, food debris and debris, a plaque is formed on the inner surface of the pipes, it grows with time. Therefore, the angle of inclination is indicated in centimeters, and not in degrees, as is customary in ordinary life. If you, too, decided to take up the construction of the sewerage system, you should familiarize yourself with the regulations and the specifics of the calculation.

Determining the slope

The slope of the external sewage system in the directories and the rest of the specialized literature has the form decimal fraction.  The ratio of the drop height to the length of the drainage is indicated by the numbers 0.07 and 0.003. These data can easily be converted into units of measurement. In this case it is about 7 cm or 3 mm per meter.

In order to determine the slope of the sewage system by 1 meter, it is necessary to multiply the slope by the pipe length. As an example, we can consider a specific case where the length of the pipe is 5600 mm and the slope is 0.07. For determining slope of sewer pipe  these two values ​​are multiplied, in the end it will be possible to get 392 mm. As the most appropriate difference in height between the end and the beginning of the drainage, a value of 39.2 cm will appear.

The main parameters in determining the slope are the length and diameter. But in the design process, many people forget that taking into account the drainage joints and the number of turns is necessary. It is recommended to take into account the number of discharge points and the characteristics of drains. For the washstand and toilet they will be different. The slope of the sewage system by 1 meter depends on the diameter of the drainage. If this value is 50 mm, then one side of the pipe should be lowered by 30 mm per meter.

For a 11-cm pipe, the slope is 20 mm per meter. With a diameter of 16 cm, the minimum slope will be 0.008 m, which is 8 mm. Calculation can be made for pipes of impressive diameters. This parameter can be 200 mm. In this case, the pipe is tilted 7 mm on each meter.

Tilting for internal piping

Having studied the sanitary norms and rules, you can understand that the slope of the pipe will depend on its diameter. This should be understood as communications in the apartment. In the bathroom and in the kitchen, different products are used, so there are normal and minimum values. In these limits, and should work. For kitchen sink and sink, bath, urinal and washbasin, pipes with a diameter of 40 or 50 mm are usually used. For them, the normal slope is 0.035. As for the minimum value, it is 0.025.

The minimum slope of sewerage should be taken into account when installation of a toilet bowl.  A 100 mm pipe is used for the branch line. The minimum slope is 0.012, while the normal slope is 0.02. It is recommended to use a bubble or laser level to determine the angle of inclination. The standard of horizontality should not be considered sex. It is cheaper to purchase a special tool than after altering the sewage system or repairing yourself or your neighbors.

Sanitary norms and rules for pipes of external sewerage

Looking at the building standards (2.04.03-85), you can find out that there are optimal dimensions of the slope for external pipes. Their diameter will be larger in comparison with the internal drainage. To exceed the recommended values ​​is not possible, otherwise the sewerage will not work properly, the pipes will be silted and quickly clogged. The maximum slope of the sewage system for a 150 mm pipe is 0.008 m or 0.8 cm per meter of length. If the pipeline has a diameter of 200 mm, this value will be less, it will be 0.7 cm or 0.007 m.

Conditions can arise when it is not possible to create a normal bias. In this case, use the minimum values. For the first case, they are 0.007 m or 0.7 cm. In the case of a 200 mm pipe, they are 0.005 m or 0.5 cm. For each meter, the maximum allowable slope is 15 cm or 0.15 mm.

Sanitary norms and rules for the fullness of sewer pipes

The sewage system should be equipped according to the rules that determine the fullness of the pipes. For the calculation, we should use the formula K = H / D, in which the letter K refers to the fullness of the pipe. The letter H determines the height of the sewage level. The diameter of the sewer pipe is D.

The filling index is equivalent to one if the pipe is flooded. For an empty drainage system, the value of K is zero. The optimum value is in the range from 0.5 to 0.6. This is true if the system is operating in normal mode. The value can vary within these limits, which will depend on the materials at the base of the products. They differ in the ability to form a boundary layer.

For ceramic or asbestos-cement pipes, the filling factor is 0.6. They are characterized by roughness, which can not be said about plastic products. The recommended fullness for the latter is 0.5. If these values ​​are met, then wastewater  will pass at a speed equal to 0.7 m per second. This is sufficient to ensure that the solid particles are kept in a suspended state and do not settle, and also do not stick to the walls.

About sewer risers

The sewerage stand should also be installed with due regard for sanitary norms and rules. When moving an element from a vertical position to a horizontal pipeline, it is not permissible to use a 90 ° elbow. The following variations can be applied:

• three bends of 30 °;
• two branches 45 ° each;
• four branches of 22.5 ° each.

In each case, the angle of the slope of the system from the riser to the horizontal pipe must be carried out not by one transition. If this rule is observed, it will be possible to reduce the turbulence of the flow and avoid frequent blockages. The sewage stand is arranged on a different principle, if the wiring is done using several plumbing fixtures, the number of which sometimes reaches six.

Sewerage scheme of a private house

Sewerage in a private house, the scheme of which will be described below, should be settled according to SNIP. As for the internal system, its main riser should be installed closer to the wall, through which the sewer is taken out. This wall should be located as close to the sewer, which is at the lowest point of the site.

The sewage system provides for a vertical joint, which is usually represented by a 110 mm pipe. To her pipes are connected, which are connected with plumbing fixtures. For the toilet, these are usually straight sections using 100 mm tubes. There is another scheme that provides for the arrangement of sections with tees, branches and crosses, the diameter can vary from 32 to 80 mm.

As for the external sewage system, it must be connected to the inner pipes without taps and bends. It is better to use plastic products. They are located taking into account the level of freezing of the soil. The pipeline runs below this line so that the products do not freeze in the cold. The external sewage system provides for a well, the volume of which is calculated taking into account the drains.

Sanitary norms and rules

When building the described system, SNiP must be used. Sewage inside at the same time assumes the need for a water seal when installing plumbing fixtures. When laying internal networks, cast iron or polymer pipes are usually used. The diameter of the outlet from the house should not be less than 110 mm. Internal networks are usually equipped with ventilation. Venting of the networks is provided through joints, for this purpose, an exhaust part must be located above each of them.

If you decide to do the described work yourself, then you must be guided by the SNiP. Sewer outside must be laid using pipes having a diameter of 150 mm or more. The depth of the tray is 1.1 m. Wells must be provided for cleaning and maintenance of the networks. For self-flowing schemes it is necessary to use asbestos-cement, polymer and ceramic pipes.

You can be self-made sewer in a private house, the scheme of this system can assume the presence of a treatment plant. It is an integral part of the autonomous sewer system. Among the main treatment facilities should be allocated:

• accumulative septic tank;
• septic tanks of purifying type;
• a station for deep biological treatment or aerotank.

Conclusion

The slope of the sewage system by 1 meter must be observed. This was discussed above. If the slope angle is made too large, the gravity system will not be able to work properly. On the walls of pipes, deposits of fats and other substances will arise. Making the bias too large, you will acquire a system that will not be able to function correctly. The liquid will effectively exit, but solid fractions will remain inside.

The principle of gravity drainage is based on the movement of liquids and suspended mixtures between different elevations. In practice, this is achieved by installing sewer pipes with a slope. It should be remembered that the SNiP clearly regulates the slope of the sewer pipe for various conditions of use.

With a decrease in the angle of inclination, everything is clear - this leads to a decrease in the velocity of the fluid, which causes an increased deposition of fat and other substances on the walls of the pipes. Finally, if there is no preventive cleaning of the system, sewage clogging occurs.

But the inadmissibility of increasing the angle of inclination in many is puzzling, it would seem that in this bad, the water will drain faster. It turns out that this is the answer to the question.

Increasing the speed of movement leads to a positive effect only in liquids. Sewage drains are a mixture of liquid and solid fractions.

As the speed of the mixture increases, the following picture will appear, the liquid fraction will flow safely at a high speed, and the solids will remain in the tube, which in time will also lead to a clogging.

Therefore, the maximum slope for sewerage is clearly regulated, it should not exceed 15 cm per 1 meter (0.15), except for branches that are less than 1.5 meters in length.

Calculation of the required bias

Most often, when determining the slope of sewerage, clear standards of SNiP are used, this method is called - uncounted. But when installing complex sewer systems, sometimes you have to resort to special calculations, as this method is resorted to, with a real need, to reduce the slope (sometimes such a need arises for technical reasons).

In this case, the maximum permissible deviation from the standard is determined.  The calculation is made by special formulas, its result depends on the speed of the fluid, the diameter and the degree of filling the pipeline. But, again, we repeat, the need for such calculations arises rarely.

Angle of slope for internal sewerage

When installing the internal sewer, the following conditions must be observed.

As already mentioned, the main document regulating the slope of sewer pipes - SNiP.

According to SNIP, the minimum slope for pipes with a diameter of 50 mm should be 0.03, with pipes 110 mm, the slope should be at least 0.02.

These pipes are used for the installation of internal sewerage. When mounting it is desirable to avoid turns at right angles in any planes, it is best to apply a series connection of several taps with a smaller angle.

If this is not possible, then it is necessary to install audits (purges) in such places. All elements of the sewage system must be securely fastened, fastening is carried out with the help of special clamps, the installation step of which is equal to 10 pipe diameters.

  Internal sewerage must necessarily be provided with fan ventilation.   It not only removes possible odors, but also ensures the normal operation of the system without the breakdown of water closures.

The pipe must be located vertically without deviations. But in private houses, sometimes, for technical reasons, you have to mount and horizontal areas. They should be executed with a slight bias.

Wherein slope of the pipe should be directed towards the system. This is done to ensure that the condensate or atmospheric precipitation, which has got into the pipe, flows into the sewage system and does not stagnate.

Slope for external sewerage

For installation of external sewerage in domestic conditions, pipes with a diameter of 110 to 200 mm are most often used. The minimum slope of the sewer pipe, according to the recommendations of SNiP, is:

• for pipes with a diameter of 110 mm - 0.03;
• 160 mm - 0.008;
• 200 mm - 0.007.

During installation, the following rules must be adhered to.

The sewage line should be laid at a depth that may be less than the freezing level of the soil by 30 cm. If the pipes are laid higher, additional thermal insulation will be required.

Carrying out excavation work, digging a trench, it is necessary to remember the future bias of the system, so the bottom of the trench must correspondingly deepen.

The depth of the ditch should be greater than the level of laying of pipes by 20-30 cm. If it turned out deeper, then it is covered with a mixture of earth and sand with obligatory ramming. It will be convenient to adjust the level of the ditch with a twine stretched to the required level.

Finally, the bed under the pipe, and accordingly, the slope of the external sewage system is formed using a sand cushion, on which the system is directly mounted.
Sewer pipes are mounted by the bell to meet the flow, this will ensure maximum tightness.

If necessary, shorten the pipe, cutting is done with a simple hacksaw, a chamfer is removed along the edge of the cut. You can not trim the socket.

All used material should not have cracks, chips, or breaks. Otherwise, the silting of the system will continue.
In places of level changes, line turns are arranged by special wells.

After assembling and laying the pipes on the bed, it is necessary to check the level of the pipes. If necessary, the bedding is done, it should cover the pipe at least a third, while the pipes must be rigid, and voids under them are not allowed. Only in this way it is possible to form optimal slopes of sewerage.

  After the final adjustment, it is necessary to fill the pipe, and first it is covered with sand, this will protect the system from damage by falling clods of earth. After that, the backfilling of the trench can be done mechanically.

Compliance with the technology of laying sewer lines, as well as recommended by the size standards is the basis of normal trouble-free operation of the system. Do not think about what kind of slope sewer pipe to choose. Just open the SNiP, where you will find answers to all your questions.

The most common material for sewer networks now are plastic pipes of various sizes. With their help, it is possible to easily assemble sewerage in compliance with all requirements, and the connection of such lines to the central sewer is made with the help of special adapters.

When designing and installing a sewage system in a country house, you need to calculate everything in such a way that the system not only functions correctly, but it is reliable and, if possible, does not cause the owner any trouble. To achieve the desired result, such a notion as the slope of sewerage is very important. This applies to both the internal sewerage system and the external pipeline that connects the house to a central or local sewage system.

The angle of inclination of pipes, with a diameter of 50 and 110 mm.

Sewage is based on a self-sufficient (non-pressure) principle, and water has the property of flowing not upwards, but down. Those. if the pipes are located horizontally or with insufficient slope, then the drains entering them too slowly move or stagnate completely.

In the the result can be:

• Unpleasant smell.
• Rapid siltation and blockage.

Many owners, realizing this, are trying to increase the slope, suggesting that the more, the better. But this is also an erroneous decision, since undesirable processes occur at too high a rate of drainage of water.

Household sewage is not uniform, water does not have time to completely wash away from the inner walls of the pipe solid particles, they stick to the wall and form solid deposits, as a result:

• Siltation and blockage.
• Unpleasant smells from the sewer.
• Increased noise during the movement of drains.
• Increased loads on the pipe walls, which accelerates wear.

As we see, in both cases similar results are obtained. In fact, the slope of the sewage pipe is a long-timed, known and definite value regulated by GOST.

This parameter is influenced by the following parameters:

• The diameter of the pipe. The angle of inclination, as a rule, is inversely related to the diameter of the pipe.
• Filling capacity of the pipe. This value depends on the material of the pipe manufacturing, and is determined by the speed of movement of the liquid through the pipe. Calculated by the formula: Y= H/ D,

where Y is the required quantity, H is the level of the liquid level in the pipe, and D is equal to the diameter of the pipe. For understanding, let's define that if the pipe is empty, then the fill level is 0, and if full, then -1. Optimal averaged value: for smooth pipes of plastic - 0.5, and for pipes that do not have a smooth inner surface (rough) 0.6.

The value of the angle of inclination is measured in centimeters. For example, a value of 0.05 cm means that the pipe should be reduced by 5 cm per 1 m of length. The exact calculation is made by the formula:

K ≤ V√ Y,

where K is the desired coefficient, V is the fluid flow rate through the pipe, and Y is the fill level.

The speed of flow in a gravity free flow is considered optimal at a value of 0.7-1 m / sec. Probably, such calculations look rather difficult, but this theory, in practice everything is simpler. There are already calculated and recommended parameters.

Internal sewerage system

The angle of slope of the pipes is 160, 200 mm.

Sewer system inside the house is characterized by a large number of pipes, draining drains from various plumbing devices, and docking nodes.

As a rule, the use of pipes with a diameter not exceeding 50 mm (for drains from the bathroom, shower, sink, etc.) and from 100 to 160 mm (for connecting the toilet bowl) is practiced in the internal sewage system.

All this is connected to the riser by means of tees or crosses. The riser is located vertically, collects drains from all levels and has a diameter of 100 to 160 mm.

Calculate the slope angle according to the formula is not necessary, because there is no constant flow. Accepted slope of sewage pipefor internal sewerage system:

If the pipeline is long and various pipes are connected to it, it is difficult to calculate the slope for each individual section. You should follow the rule and choose an index from 0.015 to 0.03. To calculate the overall slope, you need to multiply the length of the tube oriented in the horizontal plane by the required angle of inclination. Those. if the pipe has a length of 5 m and the slope is 0.03 cm, then the discharge point should be 15 cm below the entry point.

Outdoor sewerage

An external sewage pipeline delivers drains from the house to and passes under the ground. For it, pipes with a diameter exceeding 100 mm are used.

To determine the slope, you can use the table:

As a rule, the average value of the slope angle for an external sewage system is assumed to be 0.02 cm, i.e. The pipeline should be lowered by 2 cm each meter.

Also, if possible, the pipeline should not contain any turns at an angle of 90º; this can lead to clogging. Pipeline configurations without turns are not always easy to achieve, in this case, a manhole should be installed at the turn of the pipes, which will provide access to the pipes for monitoring and in the event of an accident. Inspection wells are also recommended to arrange every 20-25 m of the pipeline.

When connecting the riser pipes to the external sewer pipe, vertical risers can not be directly connected to a horizontal pipe, transitions are necessary (two at a 45º angle or three at an angle of 30º).

How to lay pipes by level

To work you need a building level - laser or bubble. The laser level differs from the bubble level with increased accuracy and higher cost, therefore the bubble level is most widespread. The main thing is to make sure that it is not defective.

If we are talking about internal sewerage, then, as we know, the angle of inclination should be about 0.03 cm.

Sequencing:

• Take the meter level and to one end, using an adhesive tape, attach a bar of 3 cm.
• We collect the pipe, not using gaskets, starting from the point of entry to the sewer (the bottom point).
• In accordance with the level, raise the pipe (its upper point) to the desired height and designate the location of the fastenings.
• We fix the fastening, we assemble the pipe already with seals and fix it.

If we are talking about external sewage, then the same principle is used, but it will be more convenient to use a level of longer length. It is also necessary to take into account all the rules of installation of the external sewage system (turns, inspection, etc.).