Sewage slope standards. Slope of pipes of internal and external sewerage

What is the right one slope of sewer pipelinesfor a private house? This is primarily 50% freshness in the bathroom. And secondly, a lot of free time that would have to be spent on pipe cleaning. After all, with insufficient slope of the sewer pipes, solid particles gradually accumulate in them due to friction forces, which will eventually lead to blockage.

If the slope is too large, the likelihood of leaks will increase, and the noise level will also rise. In addition, the separation of liquid into fractions is inevitable. In other words, particulate matter will be settle at the bottom of the pipes, since their speed is significantly less than the speed of water.

Recommended values \u200b\u200bof pipe slope can be found in SNiPs 2.04.03-85 (SP 32.13330.2012). "Sewerage, external networks and structures" and 2.04.01-85 * (SP 30.13330.2012) "Internal water supply and sewerage of buildings". Since the information about maximum and minimum pipe slopes  for external and internal sewerage. But if the goal is to lay the sewers in a private house to a septic tank or cesspool, then the last normative document will be enough.

Slope of outdoor sewage pipes

Least pipe slope values \u200b\u200bfor outdoor sewage  can be found in paragraph 5.5. SP 32.13330.2012. So, according to it, the minimum slopes of pipelines and channels for the following pipe diameters must be taken:

• 150 mm  - from 0.007 to 0.008 (7-8 mm per 1 m);

• 200 mm  - from 0.005 to 0.007 (5-7 mm per 1 m).

In general, for gravity systems, this parameter depends on the speed of movement of wastewater and does not depend on the total volume of liquid.

As for the maximum slope of the pipelines, it is 0.15, provided that the pipe is longer than 1.5 meters.

Slope of pipes of the internal sewerage

The smallest slope for internal pipelines is determined in the following paragraphs SP 30.13330.2012. So, clause 8.3.2 states that in pressureless sewer networks where the fluid must move by gravity, the slope should be at least 1 / D (D is the outer diameter of the pipe in millimeters). Also in this regulatory document is paragraph 8.6.6, which limits the minimum slope of overhead pipelines to 0.005.

The maximum value of the slope of the pipelines here is limited by the number 0.15 (15 cm per 1 meter). But experts still recommend laying sewer pipes with a slope of 0.04-0.07 or 4-7 cm per 1 meter.

Next, I would like to give two tables in which you can find not only the minimum and maximum slope values \u200b\u200bfor the internal water supply, but also its optimal values \u200b\u200bwhen connecting to various sanitary devices.

Table 1. Limit values \u200b\u200bfor slope of sewer pipes, depending on their diameter.

Table 2. Optimum pipe slope for plumbing fixtures.

Example

Calculation of slope of sewer pipes

All of the above was the determination of the optimal slope of the sewer pipes in a non-calculating way (well, or almost non-calculating). But this parameter can also be found out using a special calculation, depending on the speed of the fluid, the diameter of the pipes and the level of filling of the pipelines. True, this is very long and tedious process, which is usually resorted to in the case of large sewage systems (industrial facilities, central sewage for multi-storey buildings, etc.). Those interested can use the formula presented in paragraph 8.3.2. SP 30.13330.2012 or the Callbrook-White formula.

The construction of the sewage system external, storm or internal is carried out on the basis of clear requirements given in SNiPs

Finding these regulatory documents is easy on the Web.

The correct slope of the mounted sewer pipe is the most important point that guarantees the long-term reliable operation of the entire system. This article is devoted to this topic.

Basic information

Too steep slope on the one hand allows drains to quickly reach their destination (septic tank or, for example, a cesspool), but on the other hand, high speed increases the wear of structures, because solid particles in this work like emery. Fats settle on the rough walls, and eventually form clogs there.

Such sewers in a private house usually become unusable twice as fast as properly equipped. In accordance with applicable standards, the maximum allowable slope value can be no more than 150 millimeters per meter of linear communications.

At the same time, a too shallow minimum angle or its absence is a grosser and unforgivable mistake. Such a drainage system is filled in almost 4-6 years, since the pipes cannot be cleaned naturally.

How to determine

What should be the correct bias? The value directly depends on the diameter of the pipes you have chosen. In particular, per meter running for:

• 50 mm - it is 3 centimeters;
• 110 mm - 2;
• 160 mm - only 0.8;
• 200 mm - 0.7.

As you can see, the thicker the pipe, the smaller the angle.

In general, it should be understood that the maximum slope in any case is not allowed to be made more than 15 cm per linear meter. The only exception to this rule is short (less than one and a half meters) communications.

That is, installation is always carried out with a minimum slope (calculated per linear meter) taking into account the maximum value (for the entire length of the pipe) - 15 centimeters.

Such pipes are mainly used for outdoor sewage. According to GOST, communication is mounted here with a slope of 2 centimeters per meter.

In order to determine the optimal angle suitable in your case, you need to multiply the total length of the communication by the norm calculated for a specific diameter (20 millimeters). In this case, by 10 meters, the difference between the levels of the upper end and the lower will be 20 centimeters.

Here are other standard values \u200b\u200bthat should be repelled during the construction of sewers:

• exit from the mansion is carried out at a depth of 70 cm;
• entry into a septic tank - 80;
• the distance to the treatment plant is 10 meters.

When making a calculation, consider only the diameter of the pipe leading from the house directly to:

• sewage system;
• drain hole;
• septic tank.

It should not be confused with ventilation (fan), its dimensions do not play a role here.

Occupancy rate (calculated and optimal)

AT regardless of the type of communications, you will still need to determine the level of their content. Accurate calculation of this parameter will avoid overload and, consequently, clogging.

The main thing here is the speed of the runoff. The slope value directly affects it. To do this, use the following formula: Y \u003d H / D. In particular, H is the amount of water entering the pipe, and D is its diameter.

According to SNiPs, the minimum value of the level of fullness (Y) is 0.3, the maximum is equal to unity. The last value is a 100% load of communication and indicates the absence of any bias.

The optimal filling is from 50 to 60 percent, that is, the Y that suits us is a battle result of more than 0.3 and less than 0.6.

Allowable speed when draining should be at least 70 centimeters per second. This allows solid waste to pass without adhering to the pipe walls.

Therefore, if we take as a basis the fullness of the pipe (H) by 60 millimeters with its diameter (D) 110, then we get Y, equal to 0.55. The result showed that the speed meets the requirements, that is, does not exceed the minimum allowed by SNiPs.

In exactly the same way, the slope for pipes laid underground is also calculated. The only variable is the diameter of the communications.

To summarize

• a meter running pipe with a thickness of 5 centimeters fits within a slope of 3 cm;
• for 110 mm - you need 2 cm;
• for internal and external sewer systems, the maximum value is (for the entire length of the communication) - 15 centimeters.

In addition, the rules require that when laying always take into account the level of freezing of soils in your area. This avoids the formation of ice jams in the winter. If this rule is not feasible for any reason, you can use a special heating element laid along the track.

When arranging sewage only in the bathroom, remember - pipe slopes are allowed to be minimized, since the drains in this case usually come out without solid particles and at a fairly high pressure.

Starting to work on the sewer system, first of all, draw up a plan and indicate the exact dimensions on it. This approach saves money and eliminates many unpleasant surprises.

When laying an external sewer system, dig a trench immediately with the necessary slope - so it will be easier to install the pipeline.

8

When designing a home drain, you first need to know which slope to set for the sewer.

The simplicity of the sewer installation is silent about many small nuances, non-observance of which can adversely affect a particular situation.

One of the most important points is the choice of the angle of inclination.
  An incorrect angle of inclination can cause a backlash - and everything that is lowered into the toilet or sink will return to you, or even rule out adequate operation.

Many inexperienced plumbers do not even know about such a concept as excessive bias. Everyone is accustomed to believing that if the slope is very “steep”, then the waste in this case will drain much faster, and the return of the waste will not happen.

In fact, this is not entirely correct, but this approach has the other side of the coin.

If the pipe has a steep descent, siltation occurs inside it, since the water leaves very quickly. All sewage not washed away by water sticks to the walls, thereby clogging it.

Disruption of water constipation in siphons can also happen, subsequently, an unpleasant odor will enter the house. Agree, it will not be a very pleasant moment, especially if there are guests in the house.

Another important reason to keep the pipes constantly in the water is the influx of air to the surfaces, which will cause corrosion, reducing their service life. Therefore, you must adhere to the correct bias not only in the house, but also outside it.

Maximum slope  for outer pipe  - 0.15, i.e. no more than 15 centimeters per meter. At values \u200b\u200babove this, the system will be completely ineffective.

Minimum bias

Many newly built plumbers or novice builders who independently conduct drainage, face a problem, which is the units of measurement of the slope of the pipe.

In any instruction or reference materials for setting the minimum slope of sewer pipes you will find only decimal fractions of the form 0.02, which means that for every meter there are 20 millimeters of slope.

An important factor is the calculation of the coefficient of fullness.

It is calculated as follows: the height of the water level in the pipe divided by the diameter. The most optimal value will be the variation of the coefficient in the range from 0.5 to 0.6.

Calculation according to SNiP

Referring to the rules of SNiP, it can be interpreted that the minimum slope for sewage in an apartment or a country house depends, first of all, on its diameter.

As an example, the slope of a 50 mm sewer pipe is 3 centimeters per meter per hundred square meters.

Basic rules of SNiP:

• For collectors, the angle of inclination is calculated depending on the filling, flow rate and speed of waste transportation.
• The slope of the pipe should be within acceptable limits and not exceed them.
• The slope coefficient indicates the number of meters of slope per linear meter of sewer pipe.
• In SNiP you will never find the calculation of the angle of inclination in degrees.

Calculation table for pipes of different diameters

Take, for example, the installation and removal of the sewer pipe from the toilet. Here it is best to use a pipe with a diameter of 100.

As you can see in the table, the slope according to SNiP is 1/20, this means 1 meter divided by 20, total 5 centimeters for each linear meter of the pipe.

In this way, you can calculate the necessary slope for absolutely any plumbing fixtures.

Please note that when installing the sewage system, it is worth considering what you are leading it from. For washing, for example, it is not recommended to use pipes with a diameter greater than 50 millimeters, and for a toilet - a maximum of 100 millimeters.

For 110th diameter

Most often used for general drainage and tapping into the central city sewer.

The angle of inclination can vary from 5 to 15 centimeters per linear meter of pipe.

Here, in the first place, the number of connections, various turns and the remoteness of the house from the central city sewage system will play.

Please note: pipes of such a large diameter are only suitable for laying branches to the central sewer and for removing waste from the toilet.

They can also be used for a riser if the house has several floors. For sewage from a kitchen sink, bathtub, washing machine, washbasin, etc. use pipes exclusively 40-50 mm in diameter.

And finally, the video - installation of sewers with the correct slope. Practical methods.

To lay sewer pipes made of plastic is much easier than to build a water pipe from the same plastic. Old cast iron pipes have long been rusted and clogged, and what caused the thought of replacing them? First of all, you need to consider several parameters:

• Number of joints (the fewer joints, the better).
• The number of turns (the less the better).
• The depth of the sewer pit.

In order for the sewage system to function correctly, you need to be guided by the following rules:

2) Sockets of risers must be directed in the direction of the flow of effluents. This is done in order to avoid leaks.

3) Do not shorten or cut fittings.

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

5) Carefully inspect the o-rings for defects.

6) Provide a slope of the sewer pipe by 1 meter.

Installation Rules

Normal operation of the sewer system is impossible without the proper fixing of all its elements. Unfortunately, plastic pipes succumb to such a phenomenon as deformation, in addition, poorly fixed parts under the weight of the earth will sag and change the angle of the stack. A sewer slope of 1 meter in degrees is calculated using the approximate deviation when planting pipes. They also build special fasteners above the pipes in increments of 70 centimeters. The maximum pipe slope is 15%, since a higher degree is not recommended due to frequent blockage.

Measure the slope of the sewage system by 1 meter starting from the construction and ending with the drain pit. Be sure to check the entire length for the presence of the same slope.

Pipe diameter calculations

The value of the diameter of the sewer pipe depends on the number of units of plumbing connected to the system, as well as on such values \u200b\u200bas the slope of the sewer per 1 meter. Professionals give formulas according to which a specific diameter is calculated. It depends on factors such as:

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

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

The riser and pipes connected to the sewer pit should be 100 millimeters in diameter. But if, for example, the pipe has a diameter of 150 millimeters, then the riser should 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 sewage slope (per 1 meter) in the apartment should be 4-5 centimeters from beginning to end, this will ensure a flow rate of 0.7 m / s, the pipe diameter should be 80 mm.

Fan ventilation in the sewer

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

Differential pressure sucks the liquid out of siphons and other places with water congestion, thereby giving access to the room an unpleasant odor.

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

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 stipulated what to install: a fan system (for large volumes) or a check valve (for small volumes).

It works in only one direction, namely in the air passage in only one direction. Ideal for low pressure in pipes - when draining, the valve opens and air draws into the pipe.

Sewerage system cleaning

Cleaners are parts that are installed where the pipe is turning. The same stood in Soviet cast-iron systems for cleaning from blockages. This system was introduced and - easy, convenient and practical. But over time, they abandoned it, since many believed that such a device looked unaesthetically against the general background.

Advice! The sewer slope of 1 meter - external and internal - is calculated equally. Pipe laying trenches should be level so that when falling asleep with the soil there should be no deflection or cracks.

Also, when installing inspection hatches (revisions). 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 sewage system

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

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

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.

Options for docking:

1) The connection is made by two bends at 45 degrees.

2) Three bends of 30 degrees are used.

3) Four taps of 22 degrees are used.

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

Errors in installing the sewage 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 to install the external sewage system.

2) Incorrect sewage slope of 1 meter.

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

1) Plastic pipes are laid in the ground, which is not affected by additional loads (moving for cars).

3) Sealing rubber bands are carefully selected, as they are manufactured separately from sewer pipes and may not fit or loose.

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

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

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

In order to understand what the slope of the sewer pipe should be, it is necessary to calculate the key parameter of the speed of the flow of sewage. The minimum speed is 0.7 m / s. All details are indicated in the regulatory document SNiP.

There is a special formula with which you can calculate the parameters: V √ H / d ≥ K.

V is the speed of movement of wastewater;



H is the degree of filling;

d is the diameter;

K is the coefficient (in the case of glass and plastic pipes it is 0.5, for a pipeline made of another material, 0.6).

If approximately, for each running meter of the pipeline there should be two centimeters of deviation. That is, for a pipe with a diameter of 40-50 mm, the slope of the sewer pipe per 1 meter is 3 cm. The slope of the sewer pipe is 110 mm 2 cm per meter. We recommend that you take into account the diameter, length, number of joints, the number of turns of the pipeline, as well as the number of connected plumbing fixtures.

It is also important to consider the fillability of structures. It depends on the number of people living in the house. The more people live, the greater should be the occupancy of the installation. The formula for calculating the fullness: y \u003d H \\ D (H - level height, D - pipe diameter). The optimal value of fullness is 0.5-0.6. It depends on the material from which the pipe is made. The pipe made of glass and plastic has a filling of 0.5 due to the smooth surface, the pipe made of glass and ceramic has a filling of 0.6 due to the rough surface.