The maximum allowable slope in the pipe. What should be the slope of the sewer pipe according to building codes

Gravity sewerage is a system that transports, collects and treats wastewater without the use of pumps. A key aspect in its organization is the slope of the sewer pipes. . It is he who provides gravity in the sewer. The proposed design has a number of advantages. This is the minimum cost of installation, simple maintenance.

The sewerage device in a private house is recommended to start with the organization of the slope. For the unit of measurement, it is recommended to take not a degree, but cm / running meter. Calculations must be carried out correctly, as errors lead to functional problems:

1. Slope too low (less than 1cm/meter). It provokes a decrease in the speed of movement of wastewater, which leads to the formation of deposits on the walls of the pipeline. In the long run, this can lead to blockages. The owner will have to regularly carry out preventive sewer cleaning.
2. Too much slope (greater than 4 cm/meter). The increased slope favorably affects only the gravity of the waters. However, there is also solid waste in the drains. If the speed of movement is too high, they will get stuck inside the pipeline. This can also lead to clogging.

The slope of branches less than 1.5 meters long may be slightly more than the prescribed level.

What determines the angle of inclination?

When calculating the slope, you need to focus immediately on a number of indicators. Accounting for these values ​​will provide the most accurate results.

Consider the most important values:

1. Pipeline diameter.
2. The material from which the structure is made.
3. Indoor or outdoor location of the system.

How does the sewer material affect the slope? For example, plastic pipes are smoother. That is, when installing them, it is allowed to slightly exceed the angle.

Regulations

When installing a sewer system, you need to focus on regulations. Gravity sewerage SNiP 2.04.03-85 is regulated. This is the main document that establishes the norms for the angle of inclination. The indicators are depending on the diameter of the pipeline.

Consider the values ​​given in the regulation:

This is the minimum slope of sewer pipes for gravity flow. That is, the value can be slightly increased. Why is the slope determined depending on the diameter of the pipeline? It is the diameter that determines the throughput, that is, the ability to withstand the set flow rate.

How is slope calculated?

To determine the slope, you can use not only standard values, but also a formula. The last option provides the most accuracy. All necessary formulas are also given in SNiP.

The calculation is made as follows:

V √ H/d ≥ K

The following parameters are involved in the formula:

• K=0.5 if external and internal plastic pipelines are installed.
• K \u003d 0.6 if sewage is installed from other materials.
• V is the speed of wastewater movement.
• Н/d – wastewater filling.

The angle of inclination cannot be more than 2 cm/m. The correct slope of the sewer pipe of the internal and external sewerage of 110 mm ensures the optimal speed of the movement of wastewater, at which solid elements are transported without settling.

IMPORTANT! The angle of inclination should ensure the speed of movement of drains, which is 0.7 m / s. This value is given in SNiP.

What will give the correct calculation of the slope of the sewer system?

The angle of inclination is important to determine correctly. Consider the benefits that the right angle of inclination provides:

1. Reducing system maintenance costs. Too little or too much slope leads to permanent blockages. The user of the system will have to constantly carry out preventive cleaning.
2. Water hammer warning. An incorrect angle of inclination leads to the fact that the system begins to silt. A decrease in clearance provokes a water hammer, as a result of which the water seals in the siphons are deformed. If there are no water seals, the house begins to fill with sewer smells.
3. Sewer failure warning. Sedimentation of pipes provokes an emergency stop of the system.
4. Prevention of emergencies. The wrong slope provokes pipeline breaks, leaks.
5. Fistula protection. Insufficient slope becomes a particular problem when installing a cast-iron sewer. It provokes stagnation of sewage, which leads to the formation of fistulas and cracks in pipes.

How to properly set the slope of the sewer?

So, the correct angle of inclination is found. The next step is to properly withstand it during installation.

Consider the tools for setting the angle of inclination:

• Bubble building hydraulic level, which has three marks to indicate deviation from the horizon. It must be placed on a pre-fixed pipeline on one side, and then the angle of inclination must be determined until the bubble is fixed at the mark.
• Establishment of labels for calculation at both ends of the pipeline. According to these labels, further installation is carried out.
• The laser level (level) is extremely convenient for setting the slope.

After installation, it is required to check the slope on each meter of the pipeline, up to the septic tank. This procedure must also be performed before installation.

Features of the installation of waste outlets

The installation of the system is carried out with a socket towards the wastewater. Be sure to check the slope of the sewer pipe 110 mm for external sewage to the septic tank. For this, a level is used.

Consider the basic rules for installing sewerage:

1. Preferably the least number of turns.
2. During installation, oblique type tees are used.
3. Riser must be installed close to the plumbing.
4. It is required to mount a fan riser.
5. The shortest line length is preferred.
6. It is recommended to use PVC sewer pipes, as they are easy to install.

The calculation and installation of sewerage are carried out in compliance with the necessary standards. Only in this way will you get an efficient and durable system. It is especially important to observe the slope of the sewer pipe when installing a gravity system (this is the option for removing wastewater that is used in an apartment and a private house). This parameter depends on the diameter and length of the sewer. It is selected in accordance with SNiP 2.04.03-85 and 2.04.01-85. Insufficient, as well as excessive, pipe slope can lead to many problems. In our article we will tell you what slope of the internal and external sewerage is needed, how to calculate it and what to look for.

To determine the minimum sewer slope, home craftsmen use the following methods:

1. In order not to make a calculation, some masters try to make the angle of inclination as large as possible.
2. Some craftsmen generally miss this moment or make the minimum excess, which is specified in SNiP for pipelines of a different diameter.
3. To correctly determine the slope of the sewer pipe, you need to make a special calculation, guided by the standards from SNiP and other regulatory documents.

As it may seem, too much slope of the sewer pipeline will help the drains to drain faster into the common house system. However, with a very fast flow of effluents, they do not have time to wash away all the solid particles, and they are deposited on the inner surface, forming a blockage. In addition, at high speed, the drains cover the entire lumen of the product and cause a breakdown of the water seal in the siphons. As a result, gases from the sewer pass into the room. That is why even the maximum slope of the pipeline is strictly limited by SNiP.

Important: it is forbidden to make the slope of the sewer pipeline more than 150 mm per linear meter.

The lack of slope or the smallest slope of the sewer pipe can lead to silting of the pipeline. Such a system will not be able to be cleaned naturally during the flow of water. As a result, it will regularly become clogged and require repair, which will significantly reduce the life of the entire sewer.

Attention: in order for the sewer to serve you without breakdowns and for as long as possible, it is necessary to make a preliminary calculation taking into account the norms from SNiP, according to which the excess is selected depending on the diameter and length of the pipe.

Purpose

The angle of inclination of the sewer pipe is made when installing the internal and external systems in the apartment and house, because thanks to this you can insure against many problems during the operation of the networks:

1. If the system becomes silted due to insufficient slope or its absence, then the sewer clearance will narrow, and when a large amount of water is drained, a water hammer will occur, breaking the water seals in the siphons. If there is no water seal in the siphon, unpleasant sewer gases will begin to penetrate into the apartment.
2. Silting of the main pipeline will lead to the failure of the entire system.
3. The normative slope of the sewer pipe will protect against breakthroughs and leaks that form in the basement of the house.
4. If you install cast-iron sewer elements subject to corrosion without tilting, then fistulas and holes may form in the system due to stagnant water.

Important: The inclination of the pipeline is necessary to obtain the optimal speed of movement of wastewater, at which solid particles will be transported to the end point without settling at the bottom of the product. According to the norms of SNiP, the flow rate of wastewater through the system should be 0.7 m / s.

Choosing the optimal value

To calculate the required excess, you need to know the length of the entire pipeline and its purpose. In order not to make a calculation, you can use ready-made tables from SNiP, which gives the standard slope for drain systems from various sanitary appliances:

• For draining from the bathroom, elements of 40-50 mm are used. The maximum distance from the drain to the siphon without ventilation is 1 ... 1.3 m. The slope is 1 to 30.
• The drain from the shower must be made of pipes 40-50 mm. The maximum distance is -1.5 ... 1.7 m. Excess - 1 to 48.
• The drain from the toilet is made from a pipeline measuring 10 cm. The maximum distance is up to 6 m. The slope should be 1 to 20.
• Sink: elements with a size of 40-50 mm, distance - 0 ... 0.8 m, excess - 1 to 12.
• Bidet: products with a diameter of 30-40 mm, distance - 0.7 ... 1 m, slope - 1 to 20.
• Washing: pipeline with a diameter of 30-40 mm, distance - 1.3 ... 1.5 m, excess - 1 to 36.

The combined drain from the sink, shower and bath is made from products with a size of 5 cm. In this case, the maximum distance should be no more than 1.7 ... 2.3 m, and the slope should be 1 to 48.
The optimal and minimum slope for pipes of a certain diameter connected to specific devices is also normalized:

• A pipeline with a diameter of 4-5 cm coming from the sink can have a minimum slope of 0.025 ppm, and 0.35 ppm is considered optimal.
• Products with a cross section of 10 cm, coming from the toilet, should have a minimum slope of 0.012, and the optimal one - 0.02.
• Elements with a size of 5 cm, laid from the sink, may have a minimum excess of 0.025, and the optimal value is 0.035.
• Pipes with a cross section of 4-5 cm are laid from the washbasin and bathroom with a minimum slope of 0.025 and an optimal slope of 0.035.

Excess per running meter

As a rule, the sewerage slope per 1 meter according to SNiP is determined not in degrees, but in a value that is expressed as the ratio of the excess of one end of the pipeline over the other to a linear meter of length.

So that you know what pipe slope to make per linear meter, you can use the following data:

• For elements with a cross section of 50 mm, the minimum value is 0.03 ppm, that is, one edge of a meter product must be 30 mm higher than the second.
• A pipeline with a diameter of 110 mm must have an excess of 0.02. This means that one edge is 20 mm higher than the other with a length of 1 meter.
• The 160 mm piping must have a minimum slope of 0.008 ppm. This means that the excess of the meter section is 8 mm.
• Elements with a size of 200 mm should have an excess of 0.007 ppm, that is, one end of a meter segment is 7 mm higher than the other.

Important: the larger the diameter of the pipeline, the lower the excess value.

To calculate the slope of a sewer pipeline of a certain length, it is necessary to multiply the minimum slope, which is determined taking into account the section of the element, by its total length. For example, the beginning of an element with a diameter of 110 mm and a length of 10 m should be 20 cm higher than the end, since 10 m x 0.02 (minimum slope for a 110 mm pipeline) = 0.2 meters or 20 cm.

Outdoor networks

When determining the sewer slope in a private house, one should not forget about the external network, which must be mounted with a slope to remove wastewater by gravity. Usually, for laying external networks, products of a larger diameter are used than inside the house. When determining the slope, they are guided by the following standards:

1. If elements with a diameter of 150 mm are laid, then the recommended slope is 0.008 ppm. If for some reason it is not possible to observe such an excess, then it can be reduced to a value of 0.007.
2. In the case of laying a pipeline with a cross section of 200 mm, the minimum excess should be 0.007 ppm. It can be reduced if necessary to 0.005.

The indicator of the maximum slope of the external pipeline is also normalized. For elements of any diameter, it cannot be more than 0.15, that is, an excess of no more than 15 cm. With a large slope, the system will not be able to function correctly, as blockages will form.

Occupancy calculation

When performing the calculation, the filling of the pipeline is necessarily found. This value will help determine the flow rate, which is very important for finding the optimal excess at which the system can operate efficiently.

Important: to determine the filling level, the water level in the pipe must be divided by the diameter of the pipeline. The minimum occupancy according to the norms is 0.3, and the maximum is 1.

Having received the level of calculated filling, it is necessary to use a verification formula, that is, to compare the obtained value with the coefficient of optimal filling for elements from certain materials:

• for plastic and glass products it is 0.5;
• for systems made of cast iron, asbestos cement and ceramics, this value is 0.6.

For comparison, the square root is taken from the calculated value and multiplied by the minimum flow rate, which is 0.7 m/s. The resulting number must be compared with the optimal filling capacity of the system (based on the material). It must be greater than or equal to it.

The wastewater system is an integral part of any home. In order for it to function correctly, you need to properly equip it, that is, choose the right angle at which it will be laid. Many people ask a well-founded question whether, according to SNiP, a sewer slope of 1 meter will be sufficient or should it be done more (or maybe less). Let's figure it out.

On a note! Even if you equip the wastewater system at the right angle, this will not guarantee the normal and durable operation of the sewer. Since there are a number of points that need to be taken into account when installing it: location (piping inside or outside the premises), configuration, diameter and material of pipes.

What is the angle of inclination for?

Why do we need a well-defined angle of inclination of the wastewater system? Maybe it’s enough just to lay the pipes and not “bother” about how to make the sewer slope 1 meter - recommended values ​​by SNiP?

The main arguments for arranging sewers at a certain angle:

• Without it, the liquid will begin to stagnate in the pipes (and this is not good).
• Sewerage should function without any failures, despite the inability to predict the consistency and nature of the effluents.
• The main purpose of the arrangement of the slope is the desire to reduce, in practice, to a minimum the possibility of sedimentation of solid fractions (or silt) on the walls of the laid pipeline.
• Ensure silent operation of the system, while preventing the return flow of wastewater and eliminating the unpleasant smell directly in the room.

Too little or too much - which is better?

The most important thing is to determine exactly the minimum slope, since if it is too small, the wastewater will not flow out completely. As a result, you can not escape the clogging of pipes and all the ensuing consequences.

Good. Maybe then make a big slope and be sure that everything is in order with the outflow of liquid and not be engaged in calculating the minimum angle so that the slope of the sewer pipe by 1 meter - the recommended values ​​\u200b\u200bof SNiP - is observed? No, it's bad again. This is not the way out. The fact is that if the slope is too large, large fractions will absolutely accumulate in the pipe and contribute to the formation of blockage. The fact is that with a very large slope, the liquid quickly flows out, and it takes more time to remove solid elements (and there is nothing to wash them off with). As a result, the pipe is clogged, you are in a panic.

It turns out that it is necessary to find a "golden mean", namely, to determine the minimum angle of inclination of the sewage system so that it functions well. If the design and installation of the sewer system are carried out strictly in accordance with the norms of such a document as "Building Codes and Rules", that is, the slope of the sewer by 1 meter (SNiP recommended values) is maintained, then this will significantly increase the service life of the system that removes wastewater, and, of course the quality of her work.

Calculate the minimum angle of inclination

To determine the minimum angle of inclination, it is necessary to perform mathematical calculations using a certain formula. Here it is - V√H⁄D≥K: V - liquid drain speed (optimally, it is 0.7 m/s); H - the level of the waste liquid (that is, it determines the degree of fullness of the pipeline and should be about 50-60%); D - pipeline diameter; K is the coefficient of slope of the pipeline (optimally, it should vary from 0.5 to 0.7; that is, the closer to 1, the better).

Important! The degree of filling of the pipeline should not be less than 1/3.

Pipeline Slope Factor

This indicator can be determined in two ways:

• Calculate yourself using the formula - H / D.
• Refer to reference material.

On a note! The value of this coefficient, indicated in the reference book, is directly dependent on the material from which the pipes are made: 0.5 - for glass and plastic; 0.6 - for materials such as cast iron, asbestos cement or steel. Also, do not forget about the degree of roughness of the inner surface of the pipe, which negatively affectsK.

It is known from practice that approximately a slope of 20 mm (per 1 meter of the sewer pipeline) will be sufficient.

Pipe diameter

If you do not want to make any calculations, you can do without them: it is possible to determine the required slope of the sewer system, depending on the diameter of the pipes. Practical, convenient and fast.

Naturally, all this can be done if the diameter is chosen in such a way that the conditions of pipeline fullness (50-60%) and fluid velocity (0.7 m/s) are met. Otherwise, nothing will work.

As a rule, the calculation simply comes down to choosing a specific diameter (200, 150 (160), 100 (110), 80, 50 mm) and adjusting the angle of inclination, respectively.

Important! Don't forget about the margin of error.

In SNiP, depending on the diameter, the values ​​\u200b\u200bof the minimum and maximum slopes are presented. If you multiply these values ​​by 100, you will get these figures in centimeters.

Important! All these values ​​​​can be used for arranging slopes exclusively on flat areas (that is, without connection to outlet pipes, siphons and other systems).

Location of the wastewater system

There are two wastewater systems:

• Internal. This is a set of pipelines that ensure the removal of existing effluents from plumbing devices and their removal outside the building. Most often, the owners of private houses are engaged in arranging such a system on their own. Fortunately, the construction market has a wide range of various plastic elements.
• The external sewage system ensures the delivery of waste liquid from the building to the septic tank (storage and treatment complex).

Internal piping

In addition to the slope of the internal sewage system by 1 meter (SNiP recommended values), the following recommendations must be followed:

• We use pipes with a diameter of 100, 80, 50 or 40 mm (moreover, a diameter of 100 mm is used to connect general-purpose areas, that is, in places where the pipelines converge).

• We make the most optimal slope values ​​for pipes of these diameters, namely: 0.015, 0.2, 0.03 and 0.035, respectively.
• If, according to the technological process, it is necessary to use adapters (for example, when switching from a larger size to a smaller one), we do this in such a way that the evenness of the lower part of the channel is not disturbed. Otherwise, the continuity of the flow of water may be disturbed.
• We provide the necessary slope by means of fastening systems or the slope of the box in which we install the sewer system.

On a note! Be sure to observe the necessary slope when arranging the pipeline from the device to the sewer system. Moreover, we equip a turn to such a system with a tee or elbow (the slope should be about 70 degrees).

• We do not allow pipes to be bent at right angles. We use only bends (at 45 degrees and only).

On a note! If the pipe is of insignificant length, then deviation from a certain slope is quite acceptable.

External piping

In addition to the slope of the external sewage system by 1 meter (SNiP recommended values), the following recommendations must be followed:

• Depending on the soil and climatic conditions, the depth of the trench can vary between 100-200 cm.
• For the competent implementation of the necessary slope, do not forget to take into account the ever-increasing deepening. To do this, we initially make the depth 25 centimeters deeper, so that it is convenient to equip the sand support under the system.

• The line is carried out at a depth below the freezing level (by 350 mm). When laying above the level, it is worth considering reinforced thermal insulation.
• The diameter of the pipes used is 110-200 mm. In this case, the minimum slope is: 200 mm - 7 mm, 160 mm - 8 mm. But according to SNiP, the sewerage slope per 1 meter (110 mm pipes in diameter) is about 20 mm.

Remember! If you want the slope to be the most effective, follow the rule: the slope is not more than 150 mm (based on each linear meter).

• We place the pipes on the same level, without changing the slope along the entire length.

Remember! It is unacceptable to combine pipes of different diameters. Also, level differences in the gasket should not be allowed. If such a need arises, then the equipment of the manhole is mandatory.

Storm sewer

The function of storm sewers is to divert melt and rain streams (to avoid waterlogging of the area and preserve the foundation of the building).

In addition to a slope of 1 meter (SNiP recommended values), other factors must be observed, namely: the type of drainage system and the diameter of the pipe.

On a note! The minimum slope for the removal of thawed and should be as follows: 7 mm (for pipes with a diameter of 200 mm) and 8 mm (for 150 mm).

In addition, it is necessary to take into account other points: the characteristic features of the local soil, the average amount of precipitation in the region of residence and the volume of wastewater.

Pipe configuration

Is the condition of a sewer slope of 1 meter (SNiP recommended values) the only one for the quality operation of the sewage system? No. There is another important condition, without which blockage is inevitable. This is the laid pipeline configuration. After all, if it is too “tricky” and has a large number of bends, then the wastewater will not be able to quickly drain (without lingering inside the pipes) into the collector, and then straight into the treatment plant. In this case, no sewerage slope of 1 meter (SNiP recommended values) will save the situation.

Pipe material

Can be:

• plastic;
• cast iron;
• concrete;
• asbestos-cement;
• ceramic.

Most often, plastic pipes are used for the construction of an internal sewer system, and asbestos-cement, cast iron or corrugated pipes are used for the external one.

Finally

After reading the article, it becomes clear that the maximum (recommended by SNiP) will not solve the problem, but will exacerbate it. The only correct solution is to determine the minimum angle of inclination. And, of course, do not forget about the configuration and material of the pipeline. And you will be happy.

When designing a home drain system, it is important to understand what sewer pipe slope is optimal. With all the apparent simplicity of construction, the wrong choice of the angle of descent will lead to the most unpleasant consequences, and all the work will have to be redone. As a rule, home sewage works by gravity, so it is obvious that an insufficient slope will lead to poor passage, and the reverse will completely exclude the normal operation of the system.

What's wrong with being overly biased?

Inexperienced builders may be tempted to make the pipe as inclined as possible so that the sewage leaves faster. But this approach is also wrong. If the descent is too steep, silting of the pipe occurs due to the fact that the water descends too quickly, not having time to wash off the harder fractions of sewage, which then stick to the inner surface. In addition, there may be a breakdown of water constipation in the siphons, which means that air from the treatment system will enter the living quarters. Is it worth explaining in more detail what kind of smell it will bring to them?

There is another reason why pipes should not be left unfilled. In aggressive environments, the influx of air to the surfaces leads to their accelerated corrosion, and as a result, their service life is reduced.

Determining the slope value

The main difficulty faced by novice builders and those who independently perform drainage is that the slope unit is unusual for them. In all reference books and even building codes and regulations, which are the main guide for any builder, decimal fractions of the form 0.03 or 0.008 are indicated.

People who are accustomed to operating in degrees do not understand what slope of the sewer pipe these numbers mean. Everything is very simple: this fraction is the ratio of the height of the drop to the length of the pipe. The easiest way to track it is in centimeters, for example 3 cm by 1 m, or 0.8 cm by 1 m, as in the examples given. The length of the sewer pipe in meters, when multiplied by the slope, will give the total slope height over the entire duration.

For example, if the total length is 5.6 meters, and a reduction of 0.07 is required, then there should be a difference between the levels of the beginning and end of the pipe:

H \u003d 5.6 x 0.07 \u003d 0.39 m, that is, 39 cm.

Pipe fullness calculation

The main parameter that should be followed when laying a sewer pipe should be its fullness. It is calculated by the formula: y = H/D,
where:
H is the height of the water level in the pipe;
D is the diameter of the sewer pipe.

Wherein:
if y=0, then the pipe is empty;
if y=1, it is completely filled;
the optimal value for the fill (K), at which the drain works normally, is the range from 0.5 to 0.6.

This variation is explained by the different properties of the pipe materials and their ability to form a boundary layer held close to the inner surface of the pipes.

So, pipes made of glass or plastic have a smoother inner surface, and their fullness should be 0.5, while ceramic or asbestos pipes are rougher, and for them this value is 0.6.

The described filling value will provide a flow rate of approximately 0.7 m/s, which will keep solids in suspension, preventing them from sticking to the pipeline walls.

Thus, the design characteristics of the pipeline should be determined by the formula: K ≤ V√ y,
where:
K - the optimal level of occupancy (0.5 or 0.6);
V - speed;
√ y is the square root of the pipe occupancy.

How to measure slope angle

The minimum slope of the sewer pipe in the apartment depends on the diameter of the pipes being laid. According to SNiP for 50 mm pipes, it is 0.03, that is, 3 cm per meter, and for "weaving" or 85 mm - 2 cm.

The slope of the pipes of the external sewerage

The building codes and regulations indicate the optimal dimensions for the slope of external sewer pipes, which have a larger diameter compared to internal communications.

So for a pipe with a diameter of 100 or 110 mm, the slope should be 0.009. It will be 9 cm. If the length of the pipe is 6 meters, then the slope should be 56 cm. That is, the bottom point of the pipe should be 56 cm lower than the top.

Special conditions mean the need to create a system when, for production reasons, it is impossible to create the desired slope, in other words, this is the maximum allowable level of reduction when something prevents the creation of an optimal slope of the external sewer pipe.

There is also a maximum value for this parameter. It is 0.15, that is, with a decrease of more than 15 centimeters for each meter of pipe, the system will work extremely inefficiently, the pipe will silt up with rapid convergence of water and will clog very quickly. Water simply will not have time to wash off solid impurities.

When calculating the slope, other features of the system can be taken into account, for example, the nature of the load. If the drain is made from an ordinary washbasin, then you should not be afraid of silting, and the slope can be made large enough, but still such that it does not allow the breakdown of water constipation in the siphons.

Slope 0.15 - the maximum allowable under any conditions

Summarizing all of the above, we can conclude that the optimal amount of sewer pipe reduction is in the range from 15 to 25 mm per meter of pipe.

Made of plastic, much easier than building plumbing from the same plastic. Old cast-iron pipes have long since rusted and began to clog, which caused the thought of replacing them? First of all, you need to take into account several parameters:

• Number of joints (the fewer joints, the better).
• Number of turns (the fewer the better).
• The depth of the sewer hole.

In order for the sewer system to function properly, you must be guided by the following rules:

2) The sockets of the risers must necessarily be directed towards the flow of wastewater. This is done in order to avoid leaks.

3) Do not shorten or cut the fittings.

4) Do not use cracked or damaged pipes or their accessories.

5) Carefully inspect the O-rings for defects.

Installation rules

Normal operation of the sewer system is impossible without proper fixing of all its elements. Unfortunately, plastic pipes succumb to such a phenomenon as deformation, moreover, poorly fixed parts will sag under the weight of the earth and change the stack angle. The sewer slope per 1 meter in degrees is calculated using the approximate deviation when planting pipes. Special mounts are also constructed above the pipes in steps of 70 centimeters. The maximum slope of the pipes is 15%, since a higher degree is not recommended due to frequent clogging.

It is necessary to measure the sewer slope by 1 meter starting from the building and ending with the drain pit. Be sure to check the entire length for the same slope readings.

Pipe Diameter Calculations

The value depends on the number of plumbing units connected to the system, as well as on such a value as a sewer slope of 1 meter. Professionals give formulas according to which a certain diameter is calculated. It depends on factors such as:

• The number of turns.
• Slope percentage.
• The number of joints.
• Number of plumbing.

Formulas are usually used when laying a sewer system in large enterprises, and in private houses or apartments this is not necessary.

The riser and pipes connected to the sewer pit must be 100 millimeters in diameter. But if, for example, the pipe has a diameter of 150 millimeters, then the riser must correspond to this value. It is also worth noting that to connect the toilet to the drain system, you need to use pipes with a diameter of 100 millimeters.

The sewerage slope (by 1 meter) in the apartment should be 4-5 centimeters from the beginning to its end, this will provide a flow rate of 0.7 m / s, the pipe diameter should be 80 mm.

Fan ventilation in the sewerage device

Fan ventilation is a pipe brought to the roof and connected to the sewerage system. It serves to stabilize the air pressure in the system. With sudden pressure drops, fan ventilation is the best solution.

Pressure fluctuations suck liquid out of siphons and other places with water blockage, thereby allowing unpleasant odors to enter the room.

In multi-storey buildings, the central sewer pipe does not have a slope and is installed strictly vertically, since a large amount of wastewater enters it.

When calculating factors such as the slope of the sewer pipe 100 per 1 meter and the volume of wastewater, they are usually guided by the diameter of the pipe. After calculating these values, it is agreed what exactly to install: a fan system (for large volumes) or a check valve (for small volumes).

Works only in one direction, namely - in the passage of air only in one direction. Ideal for low pressure pipes - when draining, the valve opens and air is drawn into the pipe.

Cleaning of sewer systems

Cleaners are parts installed at the point where the pipe turns. The same ones were in Soviet cast-iron systems for cleaning from blockages. This system was also introduced in the installation of plastic pipes - easy, convenient and practical. But over time, they abandoned it, since many believed that such a device looked unaesthetic against the general background.

Advice! Sewerage slope of 1 meter - external and internal - is calculated the same way. The trenches for laying pipes must be level so that there are no deflections or cracks when filling with soil.

Also, inspection hatches (revisions) are installed. The distance between them is 13-16 meters. In multi-storey buildings, such hatches were installed every four floors.

Installation of plastic to the cast iron sewerage system

Many do not have the desire to completely change the entire sewerage system, so they only change the problematic parts. And at this stage, they are faced with joining plastic pipes to old cast iron ones.

If you are a resident of a multi-storey building, then do not forget to convince all the neighbors not to use the sewer for a couple of hours in order to avoid unpleasant moments during installation. To connect such pipes, you need to use fittings that were made specifically for this purpose.

Important! When connecting the central cast-iron pipe and the plastic one, which will be connected from the apartment, the angle should not be 90 degrees.

Docking options:

1) The connection is made by two 45 degree bends.

2) Three 30 degree elbows are used.

3) Four 22 degree elbows are used.

With any option, the sewer slope per 1 meter must be calculated individually. If the system is installed in a private house, then such wiring will not be needed, only a larger diameter of the sewer pipe will be selected.

Errors during the installation of the sewerage system

Many make mistakes during installation, and the system often clogs or does not function at all. The most common mistakes:

1) The internal view of the pipe is used for the installation of an external sewage system.

2) Wrong sewer slope by 1 meter.

3) The presence of burrs on the pipes after sawing.

1) Laying of plastic pipes is carried out in the ground, which is not affected by additional loads (moving for cars).

3) Sealing rubbers are carefully selected, as they are produced separately from sewer pipes and may not fit or sit loosely.

4) Lubrication (shampoo, detergent, soap) should be used to connect the pipes. This will greatly facilitate the work.

5) For the normal functioning of the drain system, an entry gap is recommended: for a pipe of 50 millimeters - 0.36 cm, and for 100 millimeters - 0.47 cm.

6) To connect plumbing fixtures with a flexible hose, you need to use special sealing cuffs. The diameter of the inlet must match the diameter of the pipe.