An example of calculating the sewer slope: formulas and technological standards

What factors influence the choice of roof slope

Despite the fact that humanity is constantly evolving and is no longer dependent on natural circumstances, it is these conditions that often affect the choice of slope.

Atmospheric precipitation, the accumulation of which threatens to collapse the roof or the appearance of dampness and fungus. If in a given region constant rains, downpours, thunderstorms and snowfalls are common, then the roof slope should be increased.Quick disposal of the roof from water is the key to the durability of the structure.

In regions with strong winds, such as the steppes, it is more important than ever to find a middle ground. The wind can simply fill up a too high roof, and tear off a flat one. The most optimal roof slope is from 30 to 40 degrees

In regions with strong gusts of wind - from 15 to 25 degrees

The most optimal roof slope is from 30 to 40 degrees. In regions with strong gusts of wind - from 15 to 25 degrees.

When choosing a roof slope, it is imperative to take into account these two serious factors. Having understood this issue, further work on the flooring will be greatly simplified.

According to GOST and SNiPs, which operate on the territory of the Russian Federation, the roof angle should be measured only in degrees. In all official data or documents, only degree measurement is used. However, it is easier for workers and builders "on the ground" to navigate in percentage terms. Below is a table of the ratio of degree measure and percentage - for more convenient use and understanding.

Using the table is quite simple: we find out the initial value and correlate it with the desired indicator.

For measurement, there is a very handy tool called an inclinometer. This is a rail with a frame, in the middle is an axis and a division scale to which a pendulum is attached. At the horizontal level, the device shows 0. And when used vertically, perpendicular to the ridge, the inclinometer shows a degree.

In addition to this tool, geodetic, drip and electronic devices for measuring the slope are also widely used. You can also calculate the degree of slope in a mathematical way.

To calculate the slope angle, you need to find out two values: B - vertical height (from the ridge to the cornice), C - laying (horizontal from the bottom of the slope to the top). When dividing the first value by the second, A is obtained - the slope angle in degrees. If you need a percentage of the roof angle, refer to the table above.

Storm sewer networks types and system calculation

When erecting absolutely any object, it is necessary to take care not only of the reliability of the foundation and roof, but also of the quality removal of rain or melt water from the site. For this, gravity storm sewers are used, which is a complex engineering network designed taking into account all the important parameters of the facility. At the same time, the depth of the storm sewer must be observed in accordance with SNiP and GOST. Otherwise, the work of communication will be at least ineffective, and in the worst case, it will harm the environment.

Important: the rainwater drainage system from the site must fully comply with the parameters of the object:

• The total area of ​​coatings and sites from which it is necessary to remove rain or melt water;
• Floor covering material.

At the stage storm sewer design it is necessary to comply with all the rules prescribed in SanPiN

At the design stage of storm sewers, it is necessary to comply with all the standards prescribed in SanPiN 2.1.5.980-00, GOST 3634-99 and SNiP 2.04.03-85. Only in this case, the approval of the construction of a water drainage system from the site and its subsequent construction will be carried out as quickly as possible.

It will be necessary to provide the technical task to the regulatory authorities, which is drawn up in accordance with GOST 19.201-78.It prescribes detailed information about the purpose of the communication, the deadlines for its construction, methods of control over construction and technical requirements for the finished system.

In addition to the project documentation, it is worth attaching working papers in accordance with GOST 21.604-82 “Water supply and sewerage. External networks”, which will provide information in the form of drawings of the frontal and longitudinal profile of the finished communication, a plan of the entire designed network indicating its specific sections and all statements regarding the scope of installation work. We read below about what a storm sewer is and the norms for its construction in accordance with GOST and SNiP.

Sewer pipe slope calculation: basic concepts

If the sewer is gravity-flowing, then its efficiency in transporting wastewater due to the laws of gravity depends entirely on the angle of inclination. It is believed that wastewater should move through the pipeline at a speed of 0.7-1 m/s. Only in this case the flow is able to remove solid particles from the system. To keep the flow rate indicator, for each individual diameter, it is required to calculate the slope angle of the sewer pipe.

At first glance, it may seem that the angle should be measured in degrees. But in building codes and reference books on sewerage, this parameter is defined as a decimal fraction. These figures represent the ratio of level reduction to the length of a particular section of pipeline.

For example, on a pipeline section 5 m long, one end is 30 cm lower than the other. In this case, the slope of the sewer pipe will be 0.30/5=0.06.

Formula - determining the maximum, minimum value

The formula for calculating the slope of the sewer pipe

wherein:

• V speed of fluid flow (m/s);
• H filling pipeline;
• d pipe diameter;
• K is the calculated slope factor.

To determine the coefficient (slope), you can substitute V \u003d 0.7-1, d is the value of the diameter of a particular section of the pipeline, H \u003d 0.6xd (according to building codes and rules). It turns out that for a pipeline with a diameter of 100 mm per meter, a slope of 2 cm is required, with a diameter of 50 mm - 3 cm per meter.

It can be seen from the formula that the wastewater flow rate directly depends on the angle of inclination (coefficient). For optimal speed, a minimum sewer pipe slope of 0.02 and a maximum of 0.03 is required. If the roll is less than 0.02, large particles will settle and form a blockage.

If the bank is too high, the speed will increase, which will also lead to the formation of precipitation, since the water will leave too quickly, not having time to carry away the heavy particles of effluent. Increasing the flow rate can also lead to disruption of siphons and constipation.

Required standards in the apartment

When constructing a sewer, there is no need to use a formula for calculations. There is a table that defines the slopes for all taps from plumbing fixtures.

The optimal slope of the sewer pipes in the apartment
device	Drain diameter (mm)	Distance to siphon (cm)	Incline
Bath	40	100-130	0.033
Shower	40	150-170	0,029
Toilet	100	no more than 600	0,05
Sink	40	Up to 80	0,08
Bidet	30-40	70-100	0,05
Washing	30-40	130-150	0,02
Combined drain for bath, sink and shower	50	170-230	0,029
Riser	100
Withdrawal from the riser	65-754

Each section of the sewerage system in the apartment must have a siphon in the form of a device or a bend at the end so that unpleasant odors do not enter the premises. To determine the required values, the principle of the golden mean is important - 1.5-2.5 cm per meter.This is quite enough for an apartment or a country house. The use of formulas is necessary when building large facilities with a maximum volume of wastewater.

In addition, for domestic sewage, the formula is difficult to use, since there is no constant flow.

Here it is better to pay attention to another indicator - the ability to self-clean (remove solid particles)

Since domestic wastewater contains waste with different weights, for heavy components the flow rate is the determining factor, for floating it is the filling of the system diameter. When determining the correct slope, it should be borne in mind that it will be different in each individual section.

Tilt Features

But the magnitude of the slope can not always be taken as the final result. This is due to the fact that there are a number of nuances. It is explained by the properties of the liquid and the characteristics of the collector material.

small angle

Insufficient height difference contributes to slowing down the flow of fluid. As a result of the low speed, the mechanical particles contained in the wastewater settle on the walls of the collector. Oil and fat components enter into a chemical bond with them at the molecular level. A sufficiently strong connection is formed that contributes to the formation of blockage.

This phenomenon is made possible by the good adhesion properties of fatty substances. They stick to the surface of most materials used for the production of sewer pipes - cast iron, steel, asbestos, polymer.

big angle

At first glance, by increasing the angle values ​​for the slope of the sewer pipes, it is possible to create a high-speed flow and avoid the negative phenomena of settling of mechanical inclusions. In practice, exactly the opposite happens. Some zones are created in the highway in which congestion occurs.This is explained:

• There is always hydraulic friction along the pipe wall. Due to the interaction with the surface of the material, water turbulences are created that slow down part of the flow. The resistance becomes stronger as the body roughness increases. This is especially true for cast iron. The flow of moisture, clinging to the structure, loses speed. Solid particles settle on the wall. The same thing happens with fat and oil compounds.
• The creation of a slow flow in the border zone contributes to the dispersal of the rest of the liquid layer. The result is that part of the water does not carry mechanical impurities with it. The lack of a liquid "carrier" causes heavy particles to precipitate and bond to the wall.
• Good adhesion is promoted by oil and fat components, which, due to the low flow rate, have time to come into contact with mechanical particles. The development of blockage begins.

The sequence of blockage formation is different for cast iron products and polymer parts. First, solid inclusions begin to fall out, followed by gluing with an oil and fat component. In plastic products, fat is the first to react. It is fixed on the wall, picks up mechanical particles, and a congestion is formed.

High-speed fluid movement can cause a stall or, in other words, create a "water hammer". This means that a lower pressure is formed behind the “first” wave. As a result, it is likely that liquid will be captured from the siphon, which acts as a kind of water seal. The absence of such a liquid plug will cause musty unpleasant odors from the sewer to enter the room.

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.

Sewer slope pipes in private houses

Replacing sewer pipes in an apartment should begin with getting to know the existing tips. Design and construction is based on the implementation of building codes and regulations (SNiP). SNiP norms establish the smallest slopes of sewer pipes applicable for external and internal drainage systems.

A very large inclined angle of the sewer pipe leads to an increase in the rate of fluid outflow. In this case, solid impurities and particles will settle on the surface inside the drainage system, which for a certain time leads to stagnation, disruption of water seals and the spread of fetid odors. In apartments, it is sometimes difficult to comply with the required slopes for sewer pipes. It happens that, whatever the slope is, it is not always considered sufficient. In such cases, a vertical gasket is used.

Whatever the project, it is better not to exceed the existing norms and parameters. To clarify the correctness of determining the inclined corners of sewer pipes in a personal home, it is better to contact a professional.

In high-rise buildings, sewer pipes are placed not only in a horizontal position, but also vertically.

Using the calculated and optimal filling level

Also, for a plastic, asbestos-cement or cast-iron sewer pipe, the level of fullness must be calculated. This concept determines what the flow velocity in the pipe should be so that it does not become clogged. Naturally, the slope also depends on the fullness. You can calculate the estimated fullness using the formula:

• H is the water level in the pipe;
• D is its diameter.

The minimum allowable SNiP 2.04.01-85 occupancy level, according to SNiP, is Y = 0.3, and the maximum Y = 1, but in this case the sewer pipe is full, and, therefore, there is no slope, so you need to choose 50-60%. In practice, the calculated occupancy lies in the range: 0.3 Hydraulic calculation for filling capacity and slope angle

Your goal is to calculate the maximum allowable speed for the sewer device. According to SNiP, the fluid velocity must be at least 0.7 m / s, which will allow the waste to quickly pass by the walls without sticking.

Let's take H=60 mm, and the pipe diameter D=110 mm, the material is plastic.

Therefore, the correct calculation looks like this:

60 / 110 \u003d 0.55 \u003d Y is the level of calculated fullness;

Next, we use the formula:

K ≤ V√y, where:

• K - the optimal level of fullness (0.5 for plastic and glass pipes or 0.6 for cast iron, asbestos-cement or ceramic pipes);
• V is the velocity of the fluid (we take a minimum of 0.7 m/s);
• √Y is the square root of the calculated pipe occupancy.

0.5 ≤ 0.7√ 0.55 = 0.5 ≤ 0.52 - the calculation is correct.

The last formula is a test.The first figure is the coefficient of optimal fullness, the second after the equal sign is the speed of the effluents, the third is the square of the level of fullness. The formula showed us that we chose the speed correctly, that is, the minimum possible. At the same time, we cannot increase the speed, since inequality will be violated.

Also, the angle can be expressed in degrees, but then it will be more difficult for you to switch to geometric values ​​when installing the outer or inner pipe. This measurement provides higher accuracy.

Slope of sewer pipes schematically

In the same way, it is easy to determine the slope of the outer underground pipe. In most cases, outdoor communications have large diameters.

Therefore, a greater slope will be used per meter. At the same time, there is still a certain hydraulic level of deviation, which allows you to make the slope slightly less than optimal.

To summarize, let's say that according to SNiP 2.04.01-85 clause 18.2 (the norm when installing water drainage systems), when arranging the corner of sewer pipes of a private house, you must adhere to the following rules:

1. For one running meter for a pipe with a diameter of up to 50 mm, it is necessary to allocate 3 cm of slope, but at the same time, pipelines with a diameter of 110 mm will need 2 cm;
2. The maximum allowable value, both for internal and external pressure sewers, is the total slope of the pipeline from the base to the end of 15 cm;
3. The norms of SNiP require mandatory consideration of the level of soil freezing for the installation of an external sewer system;
4. To determine the correctness of the selected angles, it is necessary to consult with specialists, as well as check the selected data using the formulas above;
5. When installing sewerage in the bathroom, you can make the filling factor, respectively, and the slope of the pipe, as minimal as possible. The fact is that water comes out of this room mainly without abrasive particles;
6. Before you start, you need to make a plan.

Expert advice:

Do not confuse the method of installing sewer pipes in an apartment and a house. In the first case, vertical mounting is often used. This is when a vertical pipe is installed from the toilet bowl or shower stall, and already it goes into the main pipe, made at a certain slope.

This method can be applied if, for example, the shower or washbasin is located in the attic of the house. In turn, the laying of the external system begins immediately from the rings of the toilet bowl, septic tank or washbasin.

In order to maintain the desired angle during installation, it is recommended to dig a trench under a slope in advance, and pull the twine along it. The same can be done for gender.

What should be the slope of the sewer pipe by 1 meter

The angle of inclination of sewer pipes is measured not as usual in degrees, but in centimeters per meter, which simply indicates how much higher one end of a meter-long pipe is than the other.

Pipe laying

The principle of operation of the sewer with a drainage pump.

Proper installation of internal sewerage in a private house involves laying pipes at a slope of 20-25 mm per 1 rn. This will ensure the unhindered passage of wastewater through the pipeline, preventing the formation of blockages and without violating the self-cleaning function of the pipes. A greater slope is possible only in short sections.

For work you will need:

• pipes (polyvinyl chloride or polypropylene) with a diameter of 50, 100 mm;
• soldering iron;
• glue;
• rubber seals in sockets;
• clamps.

To install pipes inside the house, you can use polypropylene or PVC pipes. Their diameter can be different. Choosing between these two materials, it is difficult to say which one is better. Therefore, it is recommended to use those pipes that are at hand. But you need to remember that you need a soldering iron to connect polypropylene pipes. PVC, on the other hand, are connected by means of glue or rubber seals in the sockets.

The internal sewerage system, laid in a private house, is most often performed using pipes with a diameter of 50 and 100 mm. The latter is intended for the manufacture of risers in private houses built on two or three floors, for connecting a toilet bowl with them and combining all the tubes included in the sewer system when it is taken out of the building. To connect other sources of wastewater, pipes with a diameter of at least 50 mm are used.

The interconnected pipes are attached to the walls with clamps. They also fix the riser and the pipe, which is installed at the point of exit from the building.

Recommendations for the design of gravity sewers

1. Equipping the sewer yourself, draw up the simplest plan with a minimum of turns and bends. Avoid right angle pipe bends (however, 90 degree vertical angles are perfectly acceptable when laying pipes).
2. External sewerage pipes are laid from the discharge point towards the building.
3. Pipes of internal and external sewerage can shrink over time and change the angle of inclination.

Slope value for pipes of various diameters (non-calculation laying method)

In suburban construction (including in dachas when arranging septic tanks), a simple rule is often used: for pipes with a diameter of 100 mm - 3%. Such average norms are prescribed in SNiP after practical tests.

The slope of the pipes of the internal sewerage:

• 40-50 mm - slope 3 cm / m;
• 85-100 mm - slope 2 cm / m.

The slope of the pipes of the external sewerage:

• 150 mm - slope more than 0.8 cm / m;
• 200 mm - slope 0.7 cm / m.

Storm sewer closed type:

• 150 mm - slope less than 0.7 cm / m;
• 200 mm - slope less than 0.5 cm / m.

Open type storm sewer:

• drainage and asphalt ditches - slope 0.3 cm/m;
• trays and ditches with crushed stone / cobblestone - from 0.04 to 0.5 cm / m.

These values ​​are constant regardless of terrain type. The accuracy of laying is checked by a level.

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 of 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.

What happens if you make the wrong sewer slope?

Since in real field conditions it is often simply impossible to calculate small angles without errors, wise people introduced an easy-to-use unit of measurement - cm / rm, deciphered as centimeters per linear meter.

What is the slope for? In order to create and regulate the speed of water movement.

Moreover, if this bias is more than expected, then users will face some difficulties:

• Increased noise inside the sewer pipes.
• Solid particles, which are heavier, move at a slower speed than water. Therefore, a situation may arise when the water has already “run away”, but the solid particles have not had time. This leads to blockages.
• At an increased flow rate, turbulences are created near the surface of the pipes, creating an additional load on the walls. This can lead to rapid wear of pipes, increasing repair costs.

At the same time, if the slope is made too small, the flow rate is significantly reduced, with the following consequences:

• Water begins to stagnate, and solid suspended particles begin to settle, like snow, and form silt deposits.
• Blockages lead to clogged pipes. Sometimes specialists cannot get to difficult areas to break through silt plugs. Therefore, it is necessary to cut out the intended blockage site and replace it. This, of course, leads to additional and unnecessary waste for anyone.

Therefore, it is very important to adhere to the rule recommended by experts: the water velocity in sewer systems should be in the range from 0.7 to 1 m / s

How the functionality of the system depends on the slope

During the installation of the sewer system, pipes are laid either straight (parallel to the floor) or at a certain angle. The first option is unequivocally erroneous, as it blocks the movement of wastewater and, ultimately, makes the entire system inoperable.

Judging by the photo, the pipes are not even laid parallel to the floor, but with a slight slope towards the bath - that is, incorrectly. When you turn on the water in the sink, it will not flow towards the riser, but straight into the bath

The second solution is correct, but it can be executed in different ways:

1. Make sure the angle is as sharp as possible.
2. Make the slope minimal.
3. Perform installation, focusing on the numbers recommended by regulatory documents.

What will happen in each of the above cases?

Option 1. It would seem that the angle is too sharp, therefore, the steep descent of drains is not dangerous in any way. This opinion is erroneous, since the rapid flow of the liquid does not fully flush out the solid waste.

As a result, they accumulate and form blockages. The second trouble is related to the failure of water seals, the result is a specific sewer smell throughout the house or apartment.

Another undesirable and comfort-disturbing consequence is a lot of noise, which is created by sewage falling down at a high speed.

Option 2. The minimum slope is not much different from horizontal installation. The slow movement of the liquid entails silting, the formation of a thick layer of dirt on the walls of the pipes, and then regular blockages. By the way, SNiP recommends adhering to the speed of effluents in the range of 0.7-1.0 m / s.

Option 3. The most optimal solution is to provide the slope specified in the regulatory documentation, which indicates the dependence of the laying angle of the line on the diameter or length of the pipe. Let's go directly to the norms and calculations.

Indicators of the angle of inclination of the sewer in a private house

Such an indicator as the angle of inclination of the pipe when arranging the drainage system in a private house means the degree of change in its location relative to the horizontal line. The size of the slope angle is calculated as the height difference between the lowest point of the pipeline surface at its beginning and at its end. In the standard measurement system, for comparison, the angle is indicated in degrees.

If a pipe with a diameter of 50 millimeters is used, the slope per linear meter will be 0.03 m. For example, with a four-meter length of the pipeline, the difference in height will be (0.03x4) or 12 centimeters. In order to avoid mistakes, when a sewer is created, the slope per meter is determined using the correct calculation methodology.

main parameters

When laying sewer pipes with your own hands in a private house, it is very important to create their correct slope, observing all the rules when installing them. Too little slope will result in low flow within the line, allowing heavy components to be deposited and requiring all networks to be repaired in the future.

The rules for the correct laying of a sewer pipeline are to ensure sufficient speed for the movement of effluents. This indicator is one of the main ones, and it determines how efficiently the entire sewer works.

The size of the slope of the pipe depending on its diameter

The statement that the greater the slope of the pipe, the faster the flow moves, and the better the operation of the entire system, is erroneous. With a large slope, indeed, the water will leave very quickly, but this is the mistake - with the high-speed passage of water in the line, the self-cleaning of the system is significantly reduced.

In addition, this approach leads to noisy operation of the sewage system, and due to the high speed of movement, increased wear of the inner surface will occur in it.

This will lead to premature replacement of individual sections or the entire sewer will have to be repaired.

Since the speed of movement of effluents is set by the slope of the sewer pipes, there is one more parameter, which is expressed by the difference in height at the beginning of the pipeline (the highest point) and its end (the lowest point of the entire system).

The slope of 1 linear meter of sewer pipes in centimeters in height is the parameter that must be observed when laying sewers. It will be necessary to adhere to the norms for this value, since otherwise it will be necessary to dismantle the entire system, and sometimes repair or alter the water supply.

Regulations

When laying sewer pipes in a private house, it is necessary to follow the rules described in SNiP 2.04.01-85.

Optimal angles of inclination of sewer pipes according to standards

Taking into account the diameter of the pipeline, sewerage is laid with a certain slope per linear meter.

For example:

• if lines with a diameter of 40-50 mm are used, the slope should be 3 cm per linear meter;
• for pipes with a diameter of 85-110 mm, a 2-centimeter slope per linear meter is optimal.

In some cases, the slope parameters are expressed in fractional numbers, and not in centimeters per linear meter. For the above example (3/100 and 2/100), the slope information for the correct laying of sewer pipes in a private house will look like this:

• for lines with a cross section of 40-50 mm - a slope of 0.03;
• for lines with a cross section of 85-110 mm - a slope of 0.02.

What should be the slope of the sewer pipe

The building codes that the water supply and sanitation networks must meet are prescribed in the SP and SNiP and are mandatory for use. According to these rules, the slope of the drain outlets is calculated individually for each construction project. The angle of deviation of the pipeline from the conditional horizontal will depend on several factors:

• material for the manufacture of the outlet;
• cross-sectional dimensions;
• estimated fullness;
• fluid velocity inside the outlet.

In areas where calculations cannot be made, standard data are used, which are recorded in the rules.

For elements of the drainage system with a cross section of 160 mm, 85 and 110 mm, as well as 40 and 50 mm, the slope coefficient is 0.008 / 0.02 / 0.03, respectively.In other words, with a section length of 1 meter, the sewer pipe slope of 110 mm will be 2 cm, and the sewer pipe slope of 50 mm will be no more than 3.5 cm.

It is easy to see that the degree of deviation of the outlet channel depends on the size of its cross section. The smaller the slope, the greater the required slope.

In practice, a slight deviation from the set parameters is possible. The table below shows the standard and minimum allowable values ​​for bends of various sizes, while the standards for large products in the column "smallest" are reduced.

The indicated values ​​apply only if the local conditions do not allow otherwise. In normal situations, the numbers for one hundred and fifty millimeter pipes are 0.008, and for two hundred - 0.007.

The maximum slope of sewer pipes per 1 meter allowed according to SNiP is 15 hundredths. But this value is allowed to be used only for sections where, for objective reasons, it is impossible to maintain a more gentle angle of inclination, and also when the pipe is short (no more than one and a half meters).