Sewer pipe diameter: measurement and calculation. What you need to know when installing sewerage in a private house External sewerage pipe diameter

Sewage pipes diameter 50 and 110mm

In the process of building a new house or major renovation of an existing building, the question arises of choosing materials for the wastewater disposal system. Among other parameters, it is necessary to determine the diameter of the sewer pipes. It must ensure the normal functioning of the circuit. It is generally accepted to install lines with a diameter of 100 mm in toilets, and 50 mm in kitchens and bathrooms.

Size justification

The twofold difference in size is due to the fact that the toilet needs to provide a large flow of water in a short period of time. In addition, waste from this particular room can block the circulation of wastewater through pipes of small cross-section.

A natural observation may arise that much more water is drained from the bathtub into the central sewer.

This is true. However, installing a larger diameter pipe is inappropriate here. After all, all plumbing equipment is equipped with small outlets. They are not capable of providing a full load for a 100 mm main line. Therefore, it is irrational to clutter the room with large pipes.

There is also no point in looking for a pipe with a diameter of 200 mm if toilet room In addition to the toilet, a bidet is installed:

Firstly, because the simultaneous use of these two nodes is unthinkable. And to reboot the line, a long and continuous operation of both the toilet and the bidet is necessary.
Secondly, the pipe capacity is within proportional dependence from the square of the section. In other words, it will drain wastewater from two nodes just as effectively as from one.

Required diameters of sewer pipes for different rooms specified in SNiP. They are selected in such a way as to not only guarantee timely drainage of wastewater. Their sizes are verified and take into account the need free space to move air. After all, without this apartment buildings water from the ninth floor will displace air from the sewer into the apartments located below. It's unlikely that anyone will like this.

Determination of the diameter of sewer pipes

Many regulatory documents describe methods for calculating the linear parameters of sewer pipes. They are complex because they take into account many factors: intensity of use, length of horizontal sections, angle of inclination, etc.

It is not advisable to use them to organize an allotment on the scale of one apartment or private house. Another thing - practical experience. And he allows us to say that:

For any city apartment or country house with a moderate number of sanitary rooms, a pipe measuring 100 millimeters is sufficient.
For bathrooms, kitchens, urinals and bidets, lines half the size are suitable.
The inside diameter of cast iron systems decreases over time due to deposits.
In apartment buildings, risers measuring the same 100 millimeters are installed. The exception is high-rise buildings (over 5), where 150 mm systems are installed.
Horizontal sections of a multi-storey building scheme that are connected to several risers may have larger size. As a rule, it is 200 mm.
Plastic pipes, if the angles of inclination in horizontal sections are observed, are practically not overgrown with deposits.

From the above facts it follows that the diameter of plastic sewer pipes for the same area may be smaller than for metal analogues.

No wonder on modern market You will also find unusual sizes. The cross-section of polymer products can be, for example, 75.9 mm. Don't get carried away with purchasing them. The fact is that it is not always possible to select fittings and adapters for such models. But making joints only with cement or sealing materials is risky. Sooner or later, such connections will inevitably leak.

General installation rules

Installation of sewer pipes

It is necessary to firmly understand that horizontal connections can only be installed using tees. Right angles are allowed only at the points where the system is connected to the central riser. Subsequently, following this rule will help you painlessly clean your home sewer.

There are several more established axioms of installation:

A horizontally laid pipe should be smaller in size than the riser into which the waste drains.
There should be revisions at turning points. This covered with lid holes that allow you to clear the area of possible blockage. Their installation is not necessary near siphons, connection tees and other elements that can be removed. In three-story (or more) buildings, the vertical riser must have at least 2 inspection points. As a rule, in city houses these elements are installed every 3 floors. In horizontal sections of 12 meters or more, installation of an inspection is also necessary.
Under no circumstances should you plug the sewer riser at the top. This will lead to the spread of unpleasant odors throughout the floors of the house or cottage.
The horizontal lines of the circuit should be laid with a slope, regardless of the type and diameter of the pipes used. A 1 centimeter reduction in height is sufficient per linear meter of the system. In ideally installed systems this figure is 2 centimeters. But you shouldn’t get too carried away - too much bevel provokes the sound of water during release.
Sewer pipes are fastened every 10 sizes of its diameter.

The formation of counterslopes is unacceptable. The sockets must be directed against the flow of water.

Plastic systems require special attention. The fact is that they are most susceptible to thermal expansion. Therefore, during installation there is no need to insert the pipes end-to-end. A little free space (2-3 mm) and they will “play” when heated. In this case, the tightness of the system will not be affected if all sealing elements are installed.

To select the right pipelines, you must take them into account geometric parameters. One of the most important indicators is the diameter of PVC, PPE, and cast iron sewer pipes.

There are certain standards according to which the size sewer pipe depends on the area of its use. Thus, a pipeline with a diameter of 40–50 mm is installed in kitchen and sink drains, and 75–100 mm in diameter in the sewer leading from the toilet.

Standard parameters depend on the volume of water that must leave the container in a certain time. For example, in an apartment in a multi-storey building there are standard toilets, from which a large volume of water along with waste must come out in a short period of time. Therefore, in most cases, the diameter of plastic or cast iron pipes not less than 110 mm.

Table on how to choose the internal diameter for a sewer pipe depending on the use of the outlet:

If you have non-standard parameters of water supply systems, then before installing the sewer system you need to determine the relationship between the amount Wastewater and the speed of their withdrawal. For this, certain geometric parameters are calculated.

In addition to the fact that the correct diameter allows you to calculate the water drainage rate, pipe cleaning is also carried out taking this parameter into account. For example, the technology of sewer cleaning with Kärcher systems is now very popular, but they are used only on pipes with a diameter of 100 mm or more.

Pipe calculation

To individually select a pipe for installation in houses, cottages or in the country, it is necessary to calculate the permeability. To calculate the useful pipe diameter (internal d), you need to know the following parameters:

D – outer (external) diameter, mm;
B – wall thickness, mm;
m – mass linear meter pipes, g (necessary to take into account the number and type of fastenings, if necessary complete replacement pipeline);
S – cross-sectional area, mm 2.

Formulas for calculation:

S = π/4 (D 2 – d 2);

Many manufacturers polyethylene pipes mark most of the required parameters on the communication. But, as a standard, the tap is initially known only outside diameter(D) and wall thickness. Most important parameter is the internal diameter, with its help the pipe is connected to the main and the sewerage is laid, the selection of additional elements, fittings, etc.

Moreover, unlike polypropylene plastic pipes, for cast iron sewer lines, the manufacturer initially indicates the useful internal diameter. Like steel, it is designated DN. May have different meanings, in whole numbers, for example, DN 110 or DN 200. This means that this pipe has a nominal water drainage diameter of 110 or 200 millimeters, respectively.

How to determine pipe sizes

Polypropylene, polyvinyl chloride and others plastic communications foreign-made, most often indicated in inches. It may also be that you need to install fasteners on the pipeline, but its dimensions are also given in inches, while the pipe is indicated in mm.

To do this, you need to translate the known inch dimensions in millimeters. According to the data, 1 inch is 25.4 mm. It turns out that a pipe with a diameter of 2 inches = 50.8 mm, etc. Fractional values are very often used, this is how clamps, fittings, couplings and communications are marked.

Let's look at their meaning in the table:

In inches	In millimeters	In inches	In millimeters
1/8	3,2	1 1/8	28,6
1/4	6,4	1 1/4	31,8
3/8	9,5	1 3/8	34,9
1/2	12,7	1 1/2	38,1
5/8	15,9	1 5/8	41,3
3/4	19	1 3/4	44,4
7/8	22,2	1 7/8	47,6

2 1/8	54	3 1/8	79,4
2 1/4	57,2	3 1/4	82,6
2 3/8	60,3	3 3/8	85,7
2 1/2	63,5	3 1/2	88,9
2 5/8	66,7	3 5/8	92,1
2 3/4	69,8	3 3/4	95,2
2 7/8	73	3 7/8	98,4

But, when measuring a socket manually, for example, with a ruler, the nearest one is always taken minimum size. For example, the diameter in millimeters of a sewer pipe for a sink is 34. It turns out that the outer diameter is 1 ¼ inches. Be careful when selecting sizes, otherwise you will have to buy additional spacers or adapters. But the coupling is selected based on the nearest larger indicator, i.e., 34 mm will be considered 1 3/8 inches.

Video: Pipe joining different diameters in the sewer.

Steel two-way communications may have different indicators on different sides; you need to double-check the data. This can be done by experimental measurements with a caliper or plug gauge.

Table: Diameters of ceramic pipes

SNiP

Before you buy sewer pipes large diameter, you need to familiarize yourself with the requirements of SNiP. There are systems designed for use in large cities; accordingly, they have larger diameters and communications that are used in urban-type settlements or villages. Based on the standards specified in sanitary standards and rules:

For installation of sewerage systems in urban networks with a flow of more than 300 cubic meters in 24, pipes with a diameter of 150 mm are used;
To carry out the installation of drainage for production premises– up to 130 mm, but it is necessary to use a sealing collar;
Laying pipes for non-pressure sewers is permitted with communications up to 100 mm.

Various domestic and foreign companies are engaged in the production and installation of sewerage pipes. The price of communications directly depends on the diameter and material of the drain. Before installing already selected pipelines, it is advisable to consult with a specialist in order to prevent possible leaks and emergency situations due to a discrepancy between the requirements and the purchased pipes.

Which can be used when installing drainage networks in a suburban area.

As you now know, wastewater can be released using a filtration well, a septic tank, or local treatment facilities. But this is not enough to build a sewer system.

You need to know which pipes are preferable to use for installation sewer network. To do this, you need to answer the following questions: “How to choose the material and diameter of the pipes? What is better to use – HDPE polyethylene, polypropylene or high-density pipes?”

In this article, let's look at how one material differs from another and what the choice of diameter depends on.

Sewage pipe material

Today in construction they use various materials, including when laying utility networks, which include sewerage networks.

Depending on the purpose and operating conditions, sewer pipes made of the following materials are used:

ceramic;
concrete;
asbestos-cement;
cast iron;
polymer (PP, PVC, UPVC, etc.).

All sewage can be divided into household ( fecal sewer) And surface runoff melt and rainwater. Depending on the purpose of the sewer network, the conditions for its installation, the diameter and material of the pipes are selected.

Read on to find out which pipes are best to choose in which case.

Pipes for internal sewerage

Internal sewerage is laid inside buildings and is intended to drain wastewater from plumbing fixtures in external network outside the building.

The wastewater flow rate is determined according to SP 30.13330.2012 “Internal water supply and sewerage of buildings” (updated edition of SNiP 2.04.01-85*).

The calculation uses data on the number of plumbing fixtures, the second flow rates of wastewater from these fixtures, as well as the probability of their simultaneous use in order to ensure the free passage of the maximum possible flow rates by sewer pipes.

This takes into account the climatic region and the degree of improvement of the building.

To check the diameters obtained by calculation, you should use tables bandwidth ventilated and non-ventilated risers from polymer materials and from cast iron pipes (Tables 6-12 SP 30.13330.2012) depending on the height of the riser and the angle of connection of floor branches.

These types of calculations are quite complex and are used in the design of multi-apartment residential buildings and industrial enterprises.

To select pipe diameters in a country private house or bathhouse, you can use more in a simple way– tables of standards for drainage from plumbing fixtures based on equivalent costs. In this case, the second flow rate (l/s) from the sink is taken as 1 equivalent, equal to approximately 0.33 l/s.

Based on the table, pipeline diameters are accepted depending on the amount of installed plumbing equipment.

What such a table looks like is shown in the figure below (click to enlarge):

As you can see, the largest diameter (100 mm) is required to connect the toilet. To connect sinks, sinks and washbasins to the sewer system, pipes with a diameter of 40-50 mm are sufficient.

For laying internal sewerage the following materials are used:

Polyethylene;
Polypropylene;
Polyvinyl chloride;
Polybutene;
Cross-linked polyethylene;
Fiberglass.

As a rule, for internal sewerage pipes have grey colour, by which they can be distinguished from pipes for external installation, which are orange.

Peculiarities different materials Let's look at it below.

PVC and uPVC sewer pipes

Pipes made of polyvinyl chloride and uPVC (non-plasticized polyvinyl chloride) are widely used in sewer construction due to the following advantages:

light weight;
low cost of manufacturing and transportation;
ease of machining;
ease of installation of PVC pipelines.

But they also have disadvantages. These include:

deformation under the influence of elevated temperatures;
poor resistance to some chemically active substances in sewage;
flammability with the release of toxic substances during combustion.

HDPE pipes

The abbreviation HDPE means polyethylene. low pressure, which characterizes the method of manufacturing this popular modern systems drainage of material. HDPE pipes are produced in accordance with GOST 22689.2-89 “Polyethylene sewer pipes and fittings for them.”

Notable advantages of polyethylene pipes include:

high tensile strength;
increased rigidity;
temperature range from -50 to 130 degrees;
high smoothness of the inner walls of the pipe;
long service life;
ease of transportation and installation.

The disadvantages include slightly lower resistance to direct exposure to ultraviolet rays than pipes made from other materials.

Polypropylene pipes

Polypropylene pipes are characterized by the best resistance to elevated temperatures and, thanks to this, can even be used in heating systems.

In addition, polypropylene has other advantages - plasticity, resistance to mechanical damage, ease of assembly and high durability of sewer networks made from this material.

Requirements for internal sewerage

When laying internal sewerage, the requirements of SP 30.13330.2012 “Internal water supply and sewerage of buildings” should be taken into account regarding the connection of pipeline fittings and the installation of indentations.

For example, it is recommended to connect sanitary fixtures to risers using oblique crosses and tees.

As a pipe material for internal installation, it is recommended to use pipes made of modern polymer materials that have a guaranteed service life of at least 25 years without changing their physical and chemical characteristics.

In buildings, sewerage is laid hidden - in shafts, channels and boxes made of non-flammable and low-flammable materials (G2). At the same time, laying sewerage under the ceiling, in the walls and in the floor is not allowed. living rooms, bedrooms and kitchens.

The sewer riser is installed at least 20 cm above a pitched or flat unused roof and has a distance from openable windows, vents and balconies of at least 4 meters.

Requirements for internal drains

If you are building a house in which the project involves the installation of internal drains, then you should know the requirements that apply to them:

Internal drains can be installed from polyethylene and metal pipes.
The estimated flow of rainwater and the number of drains are determined according to the climatic characteristics of the design area and depend on the intensity of rain in the area.
Drains are calculated on hydrostatic pressure which may occur in case of blockage. Also, when installing fasteners, it is necessary to take into account the weight of the drain filled with water.
The passage of internal drains through residential premises is not permitted.
Inspections on drains should be installed on the first floors of buildings before release.

Pipes for external sewerage

External sewerage performs the function of draining wastewater to wastewater treatment plants or into filtration wells.

Based on the material of external sewer pipes, there are:

Cast iron;
Concrete;
Asbestos-cement;
Polymer.

Cast iron pipes

Not so long ago, cast iron pipes were the most popular choice for installing both internal and external sewerage networks.

Cast iron has excellent physical and Chemical properties, ensuring his popularity to this day. And, if cast iron can be found in internal sewerage systems today in houses built several decades ago, then cast iron is still used as pipes for external installation today.

The obvious advantages of cast iron pipes include the following qualities:

do not rust;
have high strength, which allows them to be laid in the ground without fear that the pipes will deform under the influence of the weight of the soil or loads from passing vehicles;
Cast iron pipes are very durable and have a service life of up to 80 years.

But they also have disadvantages. The main disadvantages are:

heavy weight, making transportation and installation difficult;
increased fragility - the pipe can be split by hitting it with a hammer or carelessly hitting it against a stone;
the inner surface of cast iron pipes is not as smooth as that of polymer pipes, and gradually builds up on it various pollution, which leads to a narrowing of the bore diameter of the pipes and the appearance of blockages;
significant cost compared to plastic pipes.

Ceramic pipes

At economic justification in external sewerage networks, pipes made of ceramics are used, manufactured in accordance with GOST 286-82 “Ceramic sewer pipes”.

Ceramic pipelines have high strength to physical activity, resistant to chemical composition drains and have significant durability.

The disadvantages include fragility and labor-intensive installation. For product diameters up to 600 mm long ceramic pipes Available in lengths of only 1500 mm.

A very popular choice for installing small-diameter sewer outlets is asbestos-cement pipes in accordance with GOST 1839-80 “Asbestos-cement pipes and couplings for non-pressure pipelines.”

They are easy to install, weigh less than ceramic or cast iron pipes, are also resistant to aggressive chemical environments and have good wall smoothness, which reduces the likelihood of blockages.

Asbestos-cement pipelines are assembled using couplings.

Modern polypropylene or polyethylene pipes can also be used for laying external sewer networks.

They can be distinguished from pipes for internal installation by characteristic stiffening ribs, thanks to which the pipe looks like corrugation. Double walls and ring reinforcements give such pipes strength sufficient to support the weight of the soil when laid at a standard depth.

Plastic pipes are much easier to install than cast iron, ceramic or asbestos-cement pipes.

The video below shows the installation of plastic corrugated polypropylene pipes.

Today one of necessary conditions For comfortable stay in a private house is the presence of a sewer system that works efficiently. Nowadays, this is no longer a luxury, but a norm of life.

Before installing a sewer network, you need to make a design and correctly calculate all the parameters, one of the most important of which is the diameter of the sewer pipes.

Main characteristics of the sewer network

In order to decide which sewer system is best installed in a private house, you need to know the structural system of the sewer network. It is divided into the following types:

Internal;
External.

Internal sewerage is laid inside the house to receive wastewater from plumbing units, such as a toilet, bathroom, kitchen, and discharge it to an external system. To do this you need to install:

Boner;
Fan pipe;
Pipe layouts.

Sewerage can be laid in several options:

Hidden;
Open.

In the hidden version, pipes are laid inside the wall or floor, and in open version they are secured with clamps directly to the wall or floor.

External sewerage is located outside the private house. Previously, wastewater was collected everywhere in cesspool, which is a special container underground. From time to time, as it is full, it is cleaned by workers special service. On this moment more apply modern methods in the form of a station deep cleaning or a storage septic tank.

What parameters need to be taken into account for sewerage?

Today, a huge range of sewage products is produced. All of them are necessarily manufactured in accordance with regulatory documents. In order to choose the right materials for the sewer network of a private house, it is necessary to study the parameters of the sewer network, namely:

Diameter of sewer pipes;
Pipe angle;
Wall thickness;
Length of products.

According to the regulatory documents SNiP, the diameter of the pipes is different sizes and depends on where they will be used:

When discharging wastewater from the toilet, a diameter of 100 mm is used;
When draining wastewater from a bathtub and washbasin, the required diameter is 40-50 mm;
For drainage from washing machine— 25 mm;
To discharge all the drainage into an external sewer, a pipe of the largest diameter is used - up to 200 mm.

In a private house, when draining wastewater underground, products are used that can withstand heavy loads. They must be strong and rigid, since a large layer of soil will lie on them. The most common use is orange pipes with a diameter of 110 mm.

Essentially important point when laying the system is the angle of inclination of the pipes. After all, the uninterrupted gravity flow of wastewater depends on how correctly it is laid. The diameter of the pipes and the angle of inclination are interdependent parameters. Depending on the diameter of the product, the angle of inclination is calculated.

If the angle of inclination of pipes in a private house is calculated incorrectly, stagnation of drains will be inevitable.

Proper installation work inside the house

To install a sewer system in a private house, you should correctly draw up a pipe routing diagram. When laying pipes, the following materials are most often used:

Cast iron;
Polypropylene;
Polyvinyl chloride.

Additionally, when carrying out installation work The following connecting elements will be needed:

Audits;
Tees;
Knee;
Adapters.

To properly install internal sewerage in a private home, you need to consider the following points:

When laying pipes, it is necessary to correctly determine the angle of inclination;
The diameter of the pipes should increase when connecting additional plumbing fixtures;
It is necessary to install water seals to protect against the penetration of unpleasant odors;
The wiring should be done correctly from the riser to the toilet with a diameter of at least 100 mm;
It is necessary to install special cleanings and revisions;
If the sewerage system will be laid in the wall, it must be wrapped with thermal insulation;
It is necessary to install a vent pipe, which serves as ventilation.

The internal sewage system runs from the toilet to the riser, and from it to the outside. The fan pipe is connected directly to the riser using an inspection. It serves for the following purposes:

Ventilation of the sewer network;
Increasing the service life of the system;
Regulating the pressure inside the system.

If a private house has one floor, then a riser may not be needed. It is very important to correctly determine the installation location outer pipe, where all the drains will go. To facilitate installation work, it is best to make “wet rooms” adjacent or close to each other. After completing the installation work, it is necessary to carry out a test run of the system to check the tightness of all plumbing units (toilet, bathtub, washbasin).

Laying external sewerage

Before you begin laying pipes, you need to dig a trench with the minimum possible number of turns. Ideal option there will be a completely straight pipe with no bends. When laying a sewer network, it is necessary to correctly take into account the depth of soil freezing. The quality of wastewater disposal depends on how correctly the external sewage system is laid. To do this, the following points must be taken into account:

Ground water level;
Laying of sewerage must be carried out on a well-compacted pad 50 mm thick;
Set the tilt angle correctly;
The depth of the outer part should be no more than 50-80 cm;
Correctly calculate the distance from the cleaning system to the pipe entrance to the house.

Very important issue is which treatment system is best to choose when laying an external sewer system. Today there are the following types of septic tanks:

Cesspool;
Septic tank with mechanical cleaning;
Autonomous treatment systems.

The cesspool is the most affordable option, since it does not require labor-intensive construction costs, but during operation it requires periodic cleaning with sewerage machines. A mechanical septic tank consists of a tank through which wastewater flows. Inside such a container, wastewater is purified using special anaerobic bacteria. Autonomous sewerage represents complex system, the main component of which is sewage treatment plants.

Currently, a huge selection of different septic tanks is produced. They differ from each other in the following characteristics:

Material;
Productivity;
The magnitude of the short-term load;
The amount of simultaneous wastewater discharge.

In order for living in a private house to be comfortable, and the sewer network to serve uninterruptedly long years, you need to choose the right type of sewer network device. The type of device depends on the following factors:

The amount of water consumed;
Plot size;
Soil features.

Taking into account all the above factors, you can do right choice to provide all the amenities of country life.

During construction own home or if necessary carry out major renovation In the apartment, their owners are faced with the need to install utilities. One of the parameters that you will have to decide on is the diameter of the sewer pipe.

You will also need:

calculate slope future system, on which the functioning of the sewerage system depends,
calculate the number of turns in the highway and their angle;
choose a pipe assembly method;
select fittings and plumbing fixtures.

For correct execution work, you need to design the future structure and select all the building materials. As for the diameter of the sewer pipe in an apartment or residential building, it is customary to use products with a cross-section of 100 millimeters in toilets, and from 40 to 50 millimeters in the kitchen and bathroom.

Sewage pipe diameter

The difference between the diameters is due to two reasons:

when the toilet is flushed, a large volume of water passes through the plumbing fixture;
Solid fractions and objects that can clog the pipe often get into the toilet if it has small size sections.

But in this case, the question arises why the diameter of the pipes in the bathrooms is small, but a significant volume of waste flows through them when they are emptied. This feature is explained simply.

The fact is that the permeability of the sewer pipe corresponds to this parameter in its narrowest place, and this is the bathtub outlet. Its sewer pipe diameter is minimal, and it is covered with a special grill. Therefore, there is no point in using large cross-section products in the bathroom.

If you install a bidet next to the toilet, then the diameter should still not exceed 100 millimeters, since the simultaneous operation of two plumbing fixtures, if it happens, is extremely rare.

Installing pipes large diameter for toilets, not only because of the need to pass solids. The fact is that there should be a small gap left in them for air.

Nuances of system arrangement

To understand why a toilet pipe diameter of such a size is needed, you should imagine closed system, in which wastewater moves at speed, completely occupying the entire internal space.

In this case, the displaced air in all outlets will be under very high pressure. It will squeeze out the water seals in plumbing fixtures, which will cause a lot of trouble for property owners. There will be a terrible smell in the bathroom and there is a high probability that you will have to wash the walls and ceiling of feces.

SNiP 2.04.01-85 describes methods for calculating the diameters of pipes for sewerage in an apartment. They are complex; they take into account the slope of the pipeline on horizontal sections of the main line, the angle of connection of the terminals with the riser and other nuances. The same documentation contains tables that provide the ability to calculate the maximum permeability of pipe products at a certain diameter size.

As practice shows:

To install the entire sewer system in houses and apartments with the optimal amount of plumbing equipment, a product with a cross-section of 100 millimeters will be sufficient.
The diameter of the sewer pipe for sinks, bathtubs and other appliances should be half that size.
If engineering Communication laid in apartment building, then the diameter of the sewer riser pipe in five-story buildings should be 100 millimeters, and in buildings with more floors - no more than 150 millimeters.
General for large quantity apartments are horizontal sections of the sewer system that combine several risers and access to sewer, can be approximately 200 millimeters in diameter.
The diameter of a cast iron sewer pipe in an apartment or private household begins to decrease after a certain time due to fouling of the inner surface different types sediments.
The diameters of plumbing plastic pipes never decrease, since their inner surface is smooth and almost does not collect fat deposits. They also do not silt, sand does not collect in them, provided that they are provided with a sufficient slope and there are no irregularities inside the products.

Based on the above information, the conclusion suggests itself that during repairs when replacing a cast iron 50 mm pipe, you can use a 40 mm plastic product.

The variety of diameters of manufactured sewer pipes is not limited to the previously mentioned sizes. IN trading network you can find pipe products made of polyvinyl chloride or polypropylene, having diameters equal to 75.90, 110,160,300 millimeters.

But, before choosing such products, you need to know that purchasing fittings or cuffs for them, designed for connection with plumbing fixtures, can sometimes be problematic. Perhaps you should not give preference to products with a non-standard cross-section.

In this case, an exception must be made for sewer pipes made of plastic with a cross-section of 200 millimeters or more, since their scope of application is arranging outlets for wells and laying sections between them. The fact is that today there is no alternative to these products. The variety of sizes of plastic sewer pipes makes them increasingly popular.

Choosing the right diameter

When selecting materials for arranging a wastewater disposal system, you should remember not only what diameter the sewer pipes are, but also take into account some of the nuances of such work:

The cross-section of a horizontal pipeline cannot be larger than the diameter of the sewer riser pipe into which waste water is discharged. In addition, you need to remember that any narrowing in the structure located in the direction of movement of the drains are places where blockages will form.
Horizontal connections must be mounted from angles and oblique tees. Angles of 90 degrees are allowed only when connecting a horizontal section of the system with sewer riser. If you follow this rule, there will be no problems if you need to clean the sewer.
It is mandatory to install revisions in the places where the sewer structure turns, which are cleaning holes with covers. An exception is allowed only when there is, for example, a tee nearby that serves to connect a sink. If necessary, it is he who will perform the audit function.
When risers are located in multi-story buildings, revisions are placed every three floors. It would not be superfluous to arrange an audit in horizontal blind areas with a length of more than 12 meters.
The sewer riser is left open at the top, which is explained by the need for air suction, otherwise the vacuum when flushing sewage on the lower floors will suck in the water seal from the plumbing fixture installed on the upper floor, and bad smell quickly spread throughout the entire apartment.
The slope of a horizontal pipe should be 1-2 centimeters per meter. If you make it larger, the water will not only make more noise when drained, but also silt up. When the slope is less, the drainage drains too slowly.
When laying a sewer system under a screed, it should be thermally insulated roll material and then the sound of water will not be heard much.
Plastic products, having a diameter of 40-300 millimeters, can be cut without problems with a hacksaw or grinder. As a result, the cut is smooth and free of burrs. Then you need to chamfer the pipe.
The sewer structure is fastened at intervals equal to ten pipe diameters.
When laying plastic pipes with a diameter of 40 to 300 millimeters, they should be left with free space in case of thermal expansion. Therefore, when inserting pipes into the socket of the previous elements, they do not need to be pushed all the way, but should be left about 0.5 centimeters. Then, during prolonged drainage of hot waste, the pipeline sections mounted end-to-end will not be damaged.
All sewer system assembled so that the sockets are positioned towards the moving liquid.