External sewer pipe diameter. Sewer pipe diameter: how to calculate

The sewer system of an apartment or a country house is a complex structure, during which you should follow the rules and recommendations of professionals. Otherwise, you can face very unpleasant consequences.

For the arrangement of the sewer system, pipes of different sizes and diameters are required. Today, two types of pipes are popular:

Plastic sewer pipes - light, comfortable, characterized by a long service life, good performance properties.
Cast iron pipes - are used for arranging sewer systems much less frequently than plastic ones because of their heaviness and high cost.

The choice of pipes for sewerage is an important and responsible task. The service life of the system depends on their quality. If you make a mistake at this stage, leaks, blockages and other troubles may occur during operation. It is important not only to choose the material from which the pipeline will be made, the fittings for the connection, but you should also accurately calculate the dimensions of the pipes.

Note! The dimensions by which sewer pipes must be manufactured are regulated by the provisions assigned in SPiP.

When arranging or overhauling the sewer system of a country house or apartment, a project is first drawn up, materials and tools for installing the pipeline are selected. The main set of works can be started only after pipes, fittings and other parts have been purchased and prepared.

It is not so easy to choose the right sewer pipes. Particular attention should be paid to the diameter of the sewer pipes, as well as to the indicators of weight and length. Also, when designing a sewer system, the following indicators should be calculated:

The slope angle, ensuring the correct, uninterrupted operation of the sewerage system, timely and quick transportation of wastewater to the cesspool.
Number of connections and turns.
Options for connecting sewer pipes to each other, with a sewer riser, with plumbing fixtures.

Today, a wide range is presented on the market, which differ not only in size, but also in the scope of use, technical characteristics, and material of manufacture. The correct choice of elements for the pipeline is the key to a reliable and long-term functioning of the sewer system, respectively, the owners will not have trouble during operation.

Diameter

The question of what diameter of sewer pipes to use is one of the most important. There are several indicators for determining the diameter of sewer pipes:

The inner diameter of sewer pipes is one of the most important indicators. It is the main criterion for classification. It is important not only when choosing pipes, but also other elements of the pipeline (tees, couplings);
The outer diameter directly depends on the inner diameter (always larger);
The nominal diameter serves as a criterion for marking pipes in production;
Nominal diameter;
Wall thickness.

If, when choosing, you gave preference to cast iron products, please note that their inner diameter decreases over time. The rough surface of the walls contributes to the retention and accumulation of fatty deposits and sewage.

If all indicators are not indicated on the pipe, they can be subtracted from those available using special formulas. The diameter of the external sewer pipe, as a rule, exceeds the diameter of the elements of the internal pipeline. The SNiP has information on what the minimum allowable dimensions for arranging a sewerage system in an apartment or a country house may be.

Note! Often, pipe parameters are indicated in inches, which is not very convenient, especially if the work is done by a non-professional. There are special tables with which you can easily convert inches to millimeters. If there is no table at hand, you can convert the inch size to metric by multiplying it by 2.54.

Weight and length

When choosing pipeline elements, the weight of the sewer pipes is also important. Modern technologies make it possible to produce not only durable, but also very light materials that are easy to handle during installation. These are plastic products presented in three versions: polypropylene, polyethylene and polyvinyl chloride. As for cast iron products, they are too heavy; when working with them, one cannot do without the use of special equipment.

Their cost depends on the weight of the pipes, because the heavier the product, the more material it took to manufacture it. The weight is determined by the length of the pipe, the ratio of the outer and inner diameters.

When arranging the sewer system, one should not neglect such an indicator as length. The larger it is, the fewer connections will have to be made. Normally, the length of the pipes varies from one to six meters. If necessary, the products can be cut with a hacksaw for metal. Cast iron pipes are adjusted to size using a grinder.

The ratio of diameter and other parameters

Weight, length, wall thickness, diameter - indicators that are mutually dependent. The purpose and scope of sewer pipes depends on them. For the arrangement of the internal pipeline and the construction of external sewage, products of different sizes are used. By choosing them correctly, you can protect yourself from breakdowns and troubles that may arise during the operation of the system.

The dependence of the main indicators of sewer pipes on the diameter is determined by the following rules:

For pipes with a diameter of 160 mm, which are used for arranging external sewage, the wall thickness is 3.9 mm. Pipes with a diameter of 110 mm are much lighter, their wall thickness is 3 mm;
Large pipes (160 mm in diameter) weigh about two kilograms per linear meter, while products with a diameter of 110 mm weigh only a kilogram.

The dependence of diameter, weight and other indicators will be different if cast iron or plastic pipes are used.

The sewer system consists of pipes of different diameters. To choose the right pipes for the pipeline, you should pay attention to all the markings on the surface of the products. There, as a rule, two indicators are indicated: wall thickness and outer diameter.

Pipe sizing

On the market or in a plumbing supermarket there is a wide selection of products that belong to the sewer pipe category. Dimensions are determined by the needs of the owner. Different products are used for arranging external, internal pipelines, connecting plumbing fixtures to the system.

If you do not have professional skills and special knowledge, in order to choose the right sewer pipes, follow the recommendations specified in SNiP. During operation, the pipe should not clog, leak.

To connect the toilet, bathtub and kitchen sink, pipes of different diameters are used. This is due to the fact that plumbing fixtures accept and release different types of sewage and work differently.

To connect a toilet bowl to the system, you will need a pipe whose diameter exceeds 100 mm. This is due to the fact that it becomes necessary to pass a lot of water in a short period of time, as well as to transport solid waste of various sizes (fecal matter, toilet paper).
A pipe with a diameter of 50 mm is suitable for connecting a bathtub and a sink. The fact is that the release of a plumbing fixture is small. Even if you install a large pipe, the water will not leave faster due to the release.

There are also pipes for connecting a shower stall, a washing machine and other appliances, but their diameter ranges from 25 to 50 mm.

Note! The diameters of sewer plastic pipes for the pipeline may be smaller than those of cast iron. Plastic products are distinguished by the fact that they have smooth inner walls that are unable to retain waste, and, accordingly, the throughput is better.

Diameter calculation

On products manufactured by manufacturers of sewer pipes, there are special markings by which their size is determined. First of all, it should be determined from what material the pipes will be used to equip the sewer system. Today you can buy a plastic pipe of almost any diameter. As for the length of the products, it can be easily adjusted with a hacksaw.

A value is applied to the plastic pipe, which determines the outer diameter of the product. Having this parameter and the wall thickness, you can easily calculate the inner diameter. The range of PVC sewer pipes includes a product line with a diameter of 25 mm to 200 mm. The length ranges from 1 to 6 meters, but it is not the main indicator, since the pipe can be cut. The most popular pipes with diameters of 110 mm.

As for cast iron products, their weight is much greater than plastic pipes. Cast iron pipes are shorter, they are produced in sizes from 1.5 to 3 m. The inner diameter of sewer pipes is indicated on the products, which can be in the range from 50 mm to 400 mm. It is possible to cut a cast-iron sewer pipe, but this is a rather time-consuming, sometimes dangerous process. Individual elements are connected using special fittings.

For the desired diameter calculation, the following formula is used:

d- internal pipe diameter, mm;
Q- heat flow, kW;
v- coolant velocity, m/s;
dT- temperature difference, deg.

Purpose of pipes of different diameters

Each pipe has its own purpose. The tables presented in SNiP allow you to calculate the required number of pipes for installing a sewer system. When choosing pipeline elements, the following data should be taken into account.

A pipe with a diameter of 100 mm is used for arranging an internal pipeline when the usual number of plumbing fixtures for an apartment or a mansion (toilet, bathtub, shower, kitchen sink, washing machine) is connected to the sewerage system.
A high-quality drain in sanitary facilities such as a bidet, a washbasin is provided by pipes whose diameter does not exceed 50 mm.
For the installation of a sewer riser in a multi-storey building, pipes with a diameter of 150 mm are used.
Exit to the cesspool, the combination of several risers is carried out using sewer pipes with a diameter of more than 200 mm.

Note! If a plastic pipe is used, its diameter may be slightly smaller than cast iron products. The patency of PVC pipes does not deteriorate during operation due to the accumulation of silt and grease inside.

Installation nuances

The construction of a sewer system is a rather complicated task. You can't do without professional advice. In order to correctly calculate the number and dimensions of pipeline elements, you should seek help in drawing up an estimate and a sewerage project from a specialist.

It is important to remember that it is impossible to make a transition from a large diameter pipe to a smaller diameter product. The junction will become a place for the formation of blockages, the occurrence of leaks, breakthroughs.

When installing the pipeline, care should be taken to carry out revisions - these are holes that open if it becomes necessary to clean the pipes.

No one is immune from accidents in sewer systems. Therefore, each owner prefers to protect himself from such a scourge in his own way. For data...

Once upon a time, dark times reigned on our planet. And there was no end in sight. But with the development of the sewer system, everything changed. It happened in ancient Rome before the beginning of the new chronology. And already in the 20th century AD, this drainage system began to settle down everywhere in all developed cities of the world. Therefore, now a person is so accustomed to this convenience that, in spite of everything, in the case of repair or construction, he is ready to endure and overcome all the difficulties associated with the installation of a sewer in his apartment or house.

And there really are enough problems. After all, it is necessary to choose the right diameter of pipes, count their number, build a sewer, and of course, choose material from which the pipes are made. This article is intended to answer the last question. Since such important indicators for us as price and service life depend on the type of material.

To date, the following types of sewer pipes:

steel;

cast iron;

ceramic;

asbestos-cement;

plastic - PVC and polypropylene polyethylene;

metal-plastic.

Let us turn to each of these types of products separately and determine their main characteristics.

Steel pipes

Pipes made of steel are most often used in the installation of water supply and heating systems. But they try not to use them for sewage, since the material is highly susceptible to corrosion. In the case of stopping their choice on this type of pipes, experts recommend covering them with bitumen or buying galvanized ones if possible.

Steel pipes are distinguished by a wide range of diameters and can be produced both welded and seamless. The latter, in turn, are more durable and reliable, but also more expensive than the former.

Table of the main characteristics of steel pipes

Index	Meaning	Note
Price	from 100 rubles/p.m.	The cost of a steel tube with a diameter of 100 mm for Central Russia for the period of 2015
Life time		The service life depends on the steel grade, wall thickness and the quality of the anti-corrosion coating. A few words about corrosion. So, on average for steel, it is 0.1 mm per year.
Mounting methods	welding, threading, couplings, flanges	The connection of steel pipes can be made in any way available today. But still the most common are welding and threading.
	anti-corrosion	Steel is susceptible to rotting, so pipes for external sewerage must be treated with waterproof compounds, for example, coated with bitumen. For wiring sewers indoors, it is enough to paint them.
Weight 1 rm. meters	about 8 kg	Weight indicated for pipe ø102x4
Available diameters		In the case of a sewerage device for a residential building, in the construction market, you can easily choose the right diameter
Maximum temperature	800°C and 60°C	Steel pipes themselves easily tolerate domestic temperatures. But the protection can soften under the influence of lower temperatures. For example, for bitumen it is set at 60°C. Therefore, if you want the pipes to last for a long time, then choose anti-corrosion protection in accordance with the temperature regime of operation.
		In steel pipes, more often than in others, it is necessary to break through the blockage that has formed. This usually happens due to a decrease in the diameter of the pipe due to corrosion.
Strength	excellent	Steel pipes have excellent strength both under the influence of high and under the influence of low temperatures. But upon impact, dents can form on them, which, if significant, will lead to rapid clogging of pipes.

Cast iron pipes

At present, it is the cast-iron pipes that were buried back in Soviet times that the management companies are trying so diligently to replace. Thanks to this, residential yards often become like a war zone - trenches, artificial hills, heavy equipment and people in overalls ready to accomplish a feat, but not today.

Cast iron pipes were used in the USSR for two simple reasons - a long service life and a low price.

Table of the main characteristics of cast iron pipes

Index	Meaning	Note
Price	from 120 rubles/p.m.	cost of a cast-iron tube with an inner diameter of 100 mm for Central Russia for the period of 2015
Life time		The service life of cast iron pipes depends on the quality of the cast iron and the composition of the anti-corrosion protection
Mounting methods	through a socket or sleeve	Cast iron pipes are produced both with a socket (broadening at the end of the pipe) and without it. In the first case, one pipe is inserted into another, and the connection is sealed with a rubber gasket and lubricated with a water-insoluble lubricant. In the second case, pipes of the same diameter are connected to each other at the end using a coupling, on which there is a clamp for tightening. It is also worth noting here that cast iron pipes are leaders in the complexity of installation.
	anti-corrosion	These pipes, just like steel pipes, need anti-corrosion treatment - painting, bitumen coating, etc. If they are produced in accordance with GOST 6942-98, then a layer of bitumen should already be applied from their inside and outside.
Weight 1 rm. meters	about 13 kg	The weight is for a pipe with an inner diameter of 100 mm and a wall thickness of 4.5 mm
Available diameters		The easiest way to find the diameters of cast iron pipes is 50, 100 and 150 mm, as they are produced according to GOST 6942-98. As for large diameters, they are produced according to GOST 9583-75. Also, according to the latest standard, it is advisable to purchase pipes if a pressure sewer with a high design pressure is planned.
Maximum temperature	400°C and 60°C
The frequency of clogging	less than in steel pipes	Due to the internal waterproofing, large particles entering the pipe will pass much better than in steel pipes. It also delays the time when the product begins to decrease in diameter due to corrosion.
Strength		Cast iron pipes can withstand significant mechanical stress. But in those cases when the tensile strength is overcome, this product does not bend, but breaks.

Ceramic pipes

Ceramic pipes are very similar in their properties to cast iron pipes. But unlike the latter, ceramic pipes do not rot. In other words, they are 100% resistant to corrosion, acids and alkalis.

In everyday life, such pipes are used quite rarely due to their high cost. Therefore, if it was decided to use this particular type of pipe, then be aware that they are laid during the construction of non-pressure industrial and domestic sewer networks.

Table of the main characteristics of ceramic pipes

Index	Meaning	Note
Price	from 800 rub./p.m.	cost of a ceramic tube with a diameter of 150 mm for Central Russia for the period of 2015
Life time		It all depends on the external operating conditions and the attitude of moles towards them.
Mounting methods	through the bell	Ceramic pipes in 99% of cases are interconnected through a socket using seals
	not required	These products are resistant to aggressive environments, water and fire without any additional protection.
Weight 1 rm. meters	about 8 kg	The weight is indicated for a pipe with an inner diameter of 150 mm and a wall thickness of 19 mm
Available diameters		In accordance with GOST 286-82, the inner diameter of pipes starts from 150 mm and ends at 600 mm. The minimum wall thickness in this case is 19 mm.
Maximum temperature	over 1000°С	For domestic needs, such pipes are quite suitable.
The frequency of clogging	less than in cast iron pipes	The likelihood of blockage in such pipes during operation is much lower than that of cast iron pipes. This is facilitated by the nominal larger diameter, smooth surface and resistance to corrosion.
Strength		The result after applying significant loads to these pipes corresponds to cast iron pipes, with the only correction that the ultimate loads, after which a chip appears, are lower than for the latter.

Asbestos-cement pipes

Asbestos-cement pipes are made by mixing such rare components as asbestos fiber and Portland cement.

When installing sewage, such pipes are rarely used due to their low strength and complexity of installation. And if they are used, then most often only for non-pressure systems (although there are modifications for pressure systems). Where they have earned their popularity is in power supply, namely in the laying of electrical cables.

Table of the main characteristics of asbestos-cement pipes

Index	Meaning	Note
Price	from 80 rubles/p.m.	The cost of an asbestos-cement tube with a diameter of 100 mm for Central Russia for the period of 2015
Life time		The service life depends on external conditions and the quality of protective compounds. For example, in such a standard as SP 41-106-200, the service life of asbestos-cement pipes for heat pipelines is indicated as 25 years.
Mounting methods	couplings, flanges	If we are talking about a new sewerage laying, then it is most convenient to butt-join these pipes using asbestos-cement or plastic couplings. In the case of repairs, most often they resort to cast-iron flanges and special bolts.
	not required	Asbestos-cement pipes do not require any special protection. But in order to extend their service life, you can “walk” with bitumen before installation.
Weight 1 rm. meters	about 10 kg	The weight is for a pipe with an inner diameter of 100 mm and a wall thickness of 9 mm
Available diameters		The main standards according to which asbestos-cement pipes are produced are GOST 539-80 *, GOST 1839-80 and GOST 11310-90. In accordance with them, the inner diameters of these pipes are 100, 150, 200, 250, 300, 350, 400, 500 mm. The minimum wall thickness is 9mm.
Maximum temperature	over 160°С	For domestic needs, such pipes are quite suitable.
The frequency of clogging	similar to cast iron pipes	These products have a slight roughness, which increases over time. For this reason, blockages can form in pipes of small diameter.
Strength		Asbestos-cement pipes do not tolerate impacts with sharp objects.

plastic pipes

These pipes primarily include products made of polyvinyl chloride (PVC), polypropylene and polyethylene. These pipes have become widespread only in our time. It is on them that the old cast-iron pipes are being replaced.

This choice of service companies is connected primarily with the fact that plastic pipes have an excellent combination of price and quality. So, at a relatively low cost, they have a long service life and resistance to decay.

A few words about the use of each type of plastic pipes. PVC pipes are often used for laying outdoor systems. This is primarily due to the fact that they are cheap and well resist aggressive environments. True, it is worth noting here that speaking of the cost of purchasing PVC pipes, one must also take into account the insulation, since this material becomes brittle under the influence of low temperatures. In addition, experts advise not to use these pipes for building an internal sewage system due to the release of toxic fumes when the polymer ignites.

Polypropylene pipes are produced in two types: for external and for internal pipelines. The first are made single-layer with moderate strength and ability to withstand low temperatures. The latter consist of two layers - a perfectly smooth inner and corrugated outer. As for strength, it is much higher than that of pipes intended for internal pipelines. Therefore, two-layer products resist well the loads exerted on them by the soil.

Polyethylene pipes are currently at the stage of conquering the market. The main argument that can move competitors is their ability not to collapse (they only deform) under the influence of frozen fluid in the pipe. Such pipes are used for the installation of non-pressure sewerage systems.

Table of the main characteristics of plastic pipes

Index	Meaning	Note
Price	from 400 rubles/p.m.	The cost of a PVC pipe with a diameter of 100 mm for Central Russia for the period of 2015
Life time		The maximum service life is set for non-pressure pipes with a medium temperature of 20°C. Accordingly, at higher temperatures and increased pressure, plastic pipes will last much less.
Mounting methods	socket, coupling, fitting, welding, gluing, carving	The connection of plastic pipes to each other can be made by any method common today. But a few points need to be clarified here. So, the connection through the socket is made using a rubber seal. If the choice fell on couplings, then they must be made of the same material as the pipes. Flanges are used in the case of joining plastic pipes with metal ones. Fittings are used to connect pipes of small diameters.
	fire fighting	Plastic pipes do not rot, which means that they do not require anti-corrosion protection. But the material from which they are made is capable of igniting with the release of toxic smoke. Therefore, indoors it does not hurt to protect them from fire.
Weight 1 rm. meters	about 4 kg	The weight is for a pipe with an inner diameter of 100 mm and a wall thickness of 4 mm.
Available diameters		PVC pipes are produced in accordance with GOST R 51613-2000, polypropylene - in accordance with GOST 26996-86. For external sewage systems consisting of polymer pipes, there is a standard - GOST R 54475-2011. In accordance with it, the limit values \u200b\u200bof plastic sewer pipes are determined.
Maximum temperature		At high temperatures, such pipes lose strength
The frequency of clogging	less than in cast iron pipes	In plastic pipes, due to the smooth inner surface, blockages appear quite rarely. This usually occurs in places of kinks and if small diameter products were used.
Strength	below the average	These pipes, compared to others, have the lowest strength at a similar material thickness.

Metal-plastic pipes

For a long time, the best minds in the world have been thinking about how to create pipes so that they are strong, like steel, and perfectly resist corrosion, like plastic. And then one day it was decided to combine metal with plastic. The product turned out to be quite durable, well processed and resistant to aggressive environments and decay, but expensive.

In addition to the high cost, this type of pipe is produced mainly in small diameters. In connection with these pipes made of metal-plastic are rarely used in the sewerage system.

Table of the main characteristics of metal-plastic pipes

Index	Meaning	Note
Price	from 500 rubles/p.m.	The cost of a metal-plastic pipe with a diameter of 63 mm for Central Russia for the period of 2015
Life time		The service life depends on the temperature of the transported medium and the pressure in the pipes. So, in non-pressure pipes, where water flows with a temperature of about 20 ° C, it is maximum.
Mounting methods	coupling, fitting	Most often, metal-plastic pipes are interconnected using compression, press and sliding fittings.
	fire fighting	The outer and inner layers of these pipes are made of plastic. So fire protection won't hurt.
Weight 1 rm. meters	about 2 kg	The weight is for a pipe with an inner diameter of 63 mm and a wall thickness of 2 mm.
Available diameters		Metal-plastic pipes are produced in accordance with GOST R 53630-2009 only in small diameters. In this regard, in the sewerage system, they can be used with great restrictions. For example, as the initial section of the pipeline from some equipment.
Maximum temperature		These pipes withstand slightly higher temperatures than ordinary plastic ones.
The frequency of clogging	less than in cast iron pipes	Suitable for plastic pipes
Strength		Due to the metal layer, these pipes withstand stronger mechanical stress than plastic pipes.

So you learned about the main characteristics of sewer pipes. It remains only to choose and buy the most suitable for you.

Sewer pipes diameter 50 and 110mm

In the process of building a new house or overhauling an existing building, the question arises of the choice of materials for the drainage 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 toilet rooms, and 50 mm in kitchens and bathrooms.

Rationale for dimensions

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

A logical remark may arise that much more water is drained from the bathroom 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 able to provide a full load for a 100 mm line. Therefore, it is irrational to clutter up the room with large pipes.

It also makes no sense to look for a pipe with a diameter of 200 mm if a bidet is installed in the toilet room in addition to the toilet:

First, because the simultaneous use of these two nodes is unthinkable. And in order to reset the line, you need a long and continuous action of both the toilet and the bidet.
Secondly, the throughput of the pipe is proportional to the square of the section. In other words, it will be just as effective in diverting drains from two nodes as it is from one.

The required diameters of sewer pipes for different rooms are indicated in SNiP. They are selected in such a way as to not only guarantee the timely removal of wastewater. Their dimensions are verified and take into account the need for free space for air movement. Indeed, without this, in apartment buildings, water from the ninth floor will displace air from the sewer into the apartments located below. Hardly anyone will like it.

Determining 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: the intensity of use, the length of horizontal sections, their angle of inclination, and so on.

To organize a tap on the scale of one apartment or a private house, it is not advisable to use them. Another thing is practical experience. And it allows us to assert that:

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

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

It is not surprising to meet unusual sizes in the modern market. The cross section of products made of polymers is, for example, 75.9 mm. Don't bother buying them. The fact is that it is far from always possible to pick up fittings and adapters for such models. And 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 must be firmly understood that horizontal connections can only be mounted using tees. Right angles are allowed only in places where the system is connected to the central riser. Subsequently, following this rule will help to painlessly clean the home sewer.

There are several more well-established axioms of montage:

The horizontally laid pipe should be smaller in size than the riser into which the drains merge.
In places of turns there should be revisions. These are holes closed with a lid, allowing you to clean the place of a possible blockage. Their installation is not necessary near siphons, connection tees and other elements that can be removed. In three-story (and more) buildings, the vertical riser must have at least 2 revision points. As a rule, in city houses, these elements are mounted every 3 floors. On horizontal sections with a length of 12 meters or more, revision installation is also required.
In no case should you jam the sewer riser at the top. This will lead to the spread of unpleasant odors throughout the floors of the house or cottage.
The horizontals of the scheme should be laid with a slope, regardless of the type and diameter of the pipes used. 1 centimeter of height reduction is sufficient per linear meter of the system. In perfectly mounted systems, this figure is 2 centimeters. But do not get carried away too much - too much bevel provokes the sound of water during release.
Fastening of sewer pipes is carried out every 10 sizes of its diameter.

The formation of counter slopes 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, it is not necessary to insert pipes "end-to-end". A little free space (2-3 mm) and they will "play" when heated. The tightness of the system in this case will not be affected if all sealing elements are installed.

To choose the right pipelines, it is necessary to take into account their 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 of the sewer pipe depends on the area of its use. So, a pipeline with a diameter of 40–50 mm is installed in kitchen and sink drains, and 75–100 mm in the sewer leading from the toilet bowl.

Standard parameters depend on the volume of water that must leave the tank in a certain time. For example, in an apartment of a multi-storey building there are standard toilet bowls, from which a large volume of water should come out in a short period of time along with waste. Therefore, in most cases, for toilet bowls, a diameter of plastic or cast iron pipes of at least 110 mm is selected.

Table on how to choose the inner diameter for the sewer pipe, depending on the use of the outlet:

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

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

Pipe calculation

For individual selection of a pipe for installation in houses, cottages or in the country, it is necessary to calculate the patency. To calculate the useful pipe diameter (internal d), you need to know the following parameters:

D – outer (outer) diameter, mm;
B – wall thickness, mm;
m is the mass of a linear meter of the pipe, g (required to take into account the number and type of fasteners, if a complete replacement of the pipeline is needed);
S - cross-sectional area, mm 2.

Formulas for calculation:

S \u003d π / 4 (D 2 - d 2);

Many manufacturers of polyethylene pipes mark most of the required parameters on communications. But, as a standard, only the outer diameter (D) and the thickness of the walls are initially known for the outlet. The most important parameter is the inner diameter, with its help, the pipe is connected to the main pipe and the sewer wiring, the selection of additional elements, fittings, etc.

At the same time, unlike polypropylene plastic pipes, for a cast-iron sewer communication, the manufacturer initially indicates a useful inner diameter. Like steel, it is designated DN. It can have different values, in integers, for example, DN 110 or DN 200. This means that this pipe has a conditional water outlet diameter of 110 or 200 mm, respectively.

How to determine pipe sizes

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

To do this, you need to convert known inch sizes to millimeters. According to the data, 1 inch is 25.4 mm. It turns out that a pipe with a diameter of 2 inches \u003d 50.8 mm, etc. Fractional values \u200b\u200bare often used, so clamps, fittings, couplings and communications are marked.

Consider their meaning in the table:

Inches	In millimeters	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 the socket manually, for example, with a ruler, the nearest minimum size is always taken. 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 choosing sizes, otherwise you will have to buy additional gaskets or adapters. But the coupling is selected based on the nearest larger value, i.e., 34 mm will be considered 1 3/8 inches.

Video: Docking pipes of 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 cork gauge.

Table: Diameters of ceramic pipes

SNiP

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

For the installation of sewerage 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 laying of a drainage system for industrial premises - up to 130 mm, but it is necessary to use a sealing cuff;
Laying pipes for non-pressure sewers is allowed with communications up to 100 mm.

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

When installing communication networks, it is important to choose the right pipes, because it depends on them how reliable the water supply, gas supply, sewerage and heating will be. Wall thickness is one of the defining parameters. The material is also important. Mostly steel pipes are laid, but their closest competitors are PVC. In this article, we will consider two systems - sewerage and heating.

About sewer networks

Pipes are produced in accordance with TU 2248-022-23208482-02. One of the key roles in the choice is played by the wall thickness, it must comply with the requirements of GOST. It is clear that this parameter is tied to the diameter of the product. To divert drains from sinks and bathtubs (but not the toilet), a product with a diameter of 75 mm is used. For the toilet, a pipe with a diameter of 100 mm or 110 mm is used. Large sizes are relevant when installing risers and outlets for drains outside the boundaries of buildings.

The larger the diameter, the thicker the wall. So, steel pipes with a diameter of 150 - 160 mm are made in such a way that the thickness is at least 3.9 mm. If the sewer is laid out from 110 mm pipes, then the parameter will be within 3 mm. In addition, the weight of the product also changes.

Heating system

The wall of the pipe, with which it is planned to install heating, is calculated using special formulas. Calculations are rounded up. Steel products are not made with a wall thickness of less than 0.5 mm. According to GOSTs, during measurements, it cannot be lower than the calculated value, which is calculated with an eye to operating conditions.

It is important to remember that heating is a system in which high temperatures are created, while the pipe wall is calculated based on the material used. Since the products are steel, the heating must be installed from analogues, the residual wall thickness of which is not lower than the values of a special series. So, for products whose diameters are 25; 45; 89; 108; 273; 325, residual values are selected 1 0; fifteen; twenty; thirty; 40; 4 5 mm. respectively.

It is the strength calculations that determine what the thickness will be. Take into account the corrosive properties of the product that is planned to be transported through pipes, operating conditions, temperature and internal pressure. All this affects which wall will be selected.

Some features of thickness calculation

Heating and sewerage are two systems that are calculated using special methods. The wall (internal and external diameter of the product) is calculated with an eye to categorization. At the same time, great attention is paid to the magnitude of internal pressure. If it is determined that the pipes are planned to be operated at a pressure of less than 10 MPa, then the general method is used. It is suitable for most products.

If the pressure is above 10 Mp, the wall thickness is calculated according to the formulas reflected in the GOST rules. When choosing a pipe, homeowners need to make sure that the wall of the product is tested for strength. This is reflected in the certificates. Products are tested for tension, compression, twisting, etc.

Heating is installed according to special standards, as it is necessary to achieve maximum system performance. Thickness is not the last indicator of reliability. Pipes are selected with a margin of safety, while their wall is calculated depending on the length of the pipeline. The thickness is determined taking into account the temperature coefficient and other features.

And what do the experts say?

It is better to entrust the choice of pipeline to experts. Only craftsmen can take into account the subtleties of products. There are many standard solutions, but it is recommended to learn more about their features. Choosing at random is fraught with excessive spending, so you should not cut off your shoulder, it is better to consult experts.