What is a vent pipe and is it needed in a private home? Fan sewer riser Sewerage device without fan pipe

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Should the sewer system “breathe”? Let's figure out why the sewer pipe is installed on the roof

I’m willing to bet that even if you paid attention to the roofs of modern two or three-story cottages, you were only surprised by the abundance of pipes removed, without even suspecting that among them there was also a sewer pipe. And if its purpose is a mystery to you, then you will probably want to know about its feasibility, and in general, for what purposes it is intended.

What it is

Of course, the website is not an encyclopedia, and you will probably want me to support my story with links to those regulating its purpose regulations. And this is quite understandable, because today construction marketers sell so many unnecessary products and additional elements, that a logical question involuntarily arises: is this sewer pipe not one of them? Maybe you can do without it?

No, there's no way around it. This is really important and required element sewer system of any high-rise building. Essentially, the sewer drain pipe is not designed for water movement. Its purpose is to connect the sewer system with the surrounding atmosphere.

There are several reasons for this:

From school course As physicists, you know that draft occurs in any vertical pipe. As the pressure in its upper part increases, air penetrates into the living spaces through leaky connections, and, as you understand, it does not smell like flowers;

A water seal is not a panacea, since the sewerage system has vulnerabilities in the form of connections of the sewer comb (indoor sewer system) and the siphon elbow, the tightness of which is far from ideal.

Massive discharge of water, which is not uncommon in high-rise buildings, leads to the filling of the riser, as a result of which an air front with excess pressure is formed in front of the water flow. This phenomenon can be neutralized by inspecting the basement sewerage system (if this is a private house– then excess air escapes through sewer pipe septic tank);
At the same time, behind the downward moving mass Wastewater a vacuum is formed, the force of which is sufficient to suck out the water seals (from the toilet, from the elbow under the bathtub and sink). The residues are unable to retain air and the rooms are filled with unpleasant odors.

Captain Obviousness suggests: it is possible to solve the described problems, both at the same time, with the help of a jumper between the atmosphere and the sewer system.
During a volley discharge of water, odors will escape through the sewer riser, and the water seals will remain intact.

Regulations

SNiP 2.04.01-85

This condition is realized through risers, in which the exhaust part must exit through the roof or through a ventilation shaft.

The height of the riser depends on the type of roof and is indicated in the table:

The permissible distance from the exhaust part of the riser to the balcony or nearest window is 4 meters.
Why the instructions require this is hardly necessary to explain.

SP 40-107-2003

Another set of requirements under the number SP 40-107-2003 stipulates the case of a drain pipe leaking on an existing roof. In particular, paragraph 4.8 states that the exhaust part of the riser must be equal to 3 meters. But at the same time, it is permissible to combine four or more risers within a technical floor.

It is worth noting that such a system works quite well.
But the slightest leak in any joint will lead to the fact that the owners of apartments on the upper floors will inhale “aromas”, since there is no escape from the draft created in the risers.
The narrowing at the top helps create excess pressure in them.

Installation highlights

Fan pipes still need to be installed correctly:

Underestimating the diameter of the exhaust part of the pipe is extremely undesirable. Diameter transitions from 110 to 50 mm reduce throughput 5 times. And it is quite expected that it will simply not be enough to compensate for the drop in pressure;

The horizontal part of the sewerage system must have a slope of 2 cm per linear meter . Its presence prevents the formation of air and water locks;
Removing sewer risers that open into the attic will not lead to anything good. And not only because of the smells, high humidity will quickly saturate the thermal insulation with dampness, which in turn will lead to rotting rafter system(wooden or metal trusses);
When installing a vent riser on the roof, it should be equipped with a deflector, thanks to which neither debris nor precipitation will get into the pipe. Among the advantages of the deflector, we also note increased traction in windy weather, which increases the efficiency of the entire system.

If after meeting regulatory requirements If you are still full of doubts as to whether you need sewer system ventilation or not, we offer simplified explanations:

If you are designing a house, then know that the district architect will not approve your project without drain outlets if the future building has more than 2 floors;
If the number of floors is 1-2 floors, then the number of toilets and bathrooms matters. A fan output is not needed if there is only 1 of them.

But that’s not all - even if your project includes only 2 floors with one bathroom and one bathroom, their location will play a role:

Fan pipe needed if the toilet is located at different levels;
A connection to the roof is needed if a pipe with a diameter of less than 100 mm will be used to lay the sewer;
A connection between the sewer system and the atmosphere is required if there is a swimming pool in the house;

Availability of sealed treatment facilities will also require the installation of a drain pipe.

Unforeseen moments

Let's go back to apartment buildings, where in last years There is a negative trend - during sewer repairs, residents of the upper floors unknowingly (or perhaps deliberately) dismantle the sewer riser leading to the technical floor.

If you ask about the reason for such “innovation”, then most of the answers will be typical - “who needs it?” But this intervention does not go unpunished - after a couple of weeks, a persistent and unpleasant odor appears in all apartments upstream of a given sewer riser.

In such situation the best solution a sewer valve will be installed to replace the removed section of the system. This device is structurally a “block post” - allowing air only inside the pipe and not releasing it into the room.

Let's simulate a situation in which residents have installed a sewer valve:

In normal mode, due to the resulting draft, excess pressure is formed in the upper part of the riser. It prevents moist and unpleasantly smelling air from the sewer from entering the room;
The vacuum that occurs during a volley of sewer discharge activates the valve, through which air is sucked into the system and the pressure is equalized.

The vacuum valve I describe is not a 100% guarantee against odors.
This can only be achieved by completely sealing all connections.

Author's remarks

I allow myself the rights personal experience add some useful and practical tips to the standard recommendations:

My own house, having 2 toilets and 2 baths located on different floors, was built without drainage. And at the same time, no odors were observed inside the room, since the simultaneous use of two or more outlet points is a rather rare event;

In the house of our friends, similar to my home, we designed and installed a vent outlet. At the same time, we were guided by the requirements of SNiP 2.04.01-85, in the part where the prevailing wind direction is described. It is not worth increasing the exhaust part of the riser by more than 4 meters, since it can freeze in winter;

The likelihood that the pipe will be heated by warm air rising from the house decreases with every extra centimeter of its length.
A couple of days of cold weather - and an ice plug will certainly form inside, and along with it, odors will appear in the apartment or house.

We did not install the fan outlet through the roof, but mounted it ourselves through the gable. A definite plus is the minimum amount of work required roofing material and subsequent sealing.

Conclusion

I hope that in this publication I was able not only to add to your construction glossary, but also to professionally explain how the sewage system functions in your home. And if you are a resident of the upper floors, then warn you about possible consequences unauthorized interference in its work.

As always, the video in this article will allow you to explore additional topic materials. Please feel free to leave your additions and comments. Good luck, comrades!

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What are fan pipes?

Many people have heard from friends and acquaintances that it is necessary to create an installation diagram in a private home. This is due to high-quality ventilation of the toilet, bathroom, kitchen, and entire house, which can be built using a vent pipe.

What is a fan pipe, what can it be, how to install it?

The drain pipe is connected to the sewer system and is designed to perform a ventilation and water seal function with subsequent outlet to the roof. During operation of the sewer pipeline, gases accumulate in it. If you do not install a waterproof barrier, they will penetrate into the living space, which is dangerous for the lives of the inhabitants of the apartment. In addition, an unpleasant odor will spread throughout the house.

It can be of any length, shape, depending on the installation location and the size of the sewer line. This part exhaust system can be straight, angular, placed in horizontal, vertical directions.

To prevent unpleasant odors from entering your home, it is necessary to make a high-quality one. In such cases, it helps, for the manufacture of which plastic is most often used. However, elements of metallic origin were not completely replaced. Today, many people use cast iron in their homes, less often. Metal does not want to give up its positions.

Read with this article: How to bend and connect with your own hands. Review from “A” to “Z” of this product.

Possible schemes

Laying and replacing sewer risers does not allow mistakes in the process of planning and installing the system, otherwise the living space will be filled with an unpleasant odor. To prevent this from happening, in a private house you need to choose the right drain pipe design.

There are 2 installation schemes for exhaust systems:

Horizontal.
According to this scheme, the outlet of the vent pipe must be carried out through a hole in the wall, and not through the roof. This scheme can be used in private construction if it is impossible to make an exit through the roof. The final outlet is covered by a grille rather than a deflector.
Vertical.
With this design of the fan pipe in a private house, the riser goes out through the roof.

There are three types of vertical outlet of the riser to the atmosphere:

output at an angle of 90⁰. It is necessary to make two branches from the riser, one after the other, at angles of 90⁰, after which it will come out vertically upward through the roof;
output at a slope of 45⁰. To directly exit the riser through the roof, it is necessary to alternately make a branch from the main riser, first at 45 degrees, and then at 135 degrees;
the usual vertical type outlet, which will immediately continue to the roof and exit through it to the outside.

Important! The ventilation installation diagram in a private house must be correct, that is, in accordance with suitable diameter and in the right place, anticipate the presence of the opposite, blocking the overflow of feces.

Use of cast iron elements

Over the course of several decades, the arrangement exhaust ducts occurred using cast iron risers. Today, cast iron fan pipes are becoming increasingly rare. But in vain, because using risers made of this material you can be sure of the quality of the exhaust and ventilation ducts. have a number of advantages.

They differ:

strength. The rigidity and density of the alloy contribute to safe operation, which can be purchased at a hardware store. They are used in the construction of private, multi-storey buildings;
long service life. This is due to high wear resistance, which helps maintain excellent technical characteristics for many years;
resistance to influences mechanical type. They are not afraid of accidental impacts, damage, or heavy loads.

Minuses:

tendency to corrosion processes;
difficulty of transportation;
heavy weight;
high price.

When repairing or replacing old cast iron risers, it is necessary to dismantle the existing system. It is not easy to do this if the sewer or exhaust line is located in hard to reach place. How to disassemble a cast iron pipe behind a toilet? It is difficult to carry out this procedure if tow with cement, aluminum or sulfur were used to connect the risers.

First you need to dismantle the parts that are located further from the riser. To do this, you should stock up on a chisel or a hammer with a plastic or rubber head. When you hit the chisel with an iron hammer, pieces of metal sharply bounce off the pipe and can fall into the riser, since cast iron is a very brittle alloy.

Having done everything preparatory work, start removing the cast iron fan or sewer riser:

After destroying this element of the system, gradually approach the crosspiece, leaving 30-35 cm of an almost broken part.
Using the remaining piece, gently loosen it. If this does not help, then use a chisel to start removing the packing, loosen it again, and then remove the remaining fragment.
If the system is condensed with sulfur, then it is necessary to take blowtorch or gas burner and start heating the packing. Before doing this, you need to cover the furniture and walls with a screen so as not to damage them. Preferably this work should be done by two people, since one must remove the heated viscous sulfur.
After removing a certain amount of the heated mass, remove the remainder of the unnecessary part of the part.

An option is possible when you can use a grinder to cut off the rest of the line right up to the socket. This procedure will ensure not only a neat cut, but also a quick, convenient joining of the new one to the old cast iron riser.

Important! The cast iron fan pipe can be used in any extreme situations. This means that such a system will function normally under conditions of a wide temperature range at elevated pressure.

Work with cast iron sewer or sewer pipes, including drilling them, must be carried out with the utmost care. This is due to the increased fragility of the metal.

Over a long period of operation, as a result of corrosion processes, cast iron sewer risers become unattractive. Therefore, they need to be refreshed. cast iron pipe in the toilet?

For painting use acrylic, water-dispersion paint. The shade can be very diverse.

Some owners refresh cast iron risers oil paints. Before painting, you need to get rid of rust, old peeling paint, unnecessary debris, and dirt. Only after such preparation can you begin painting. Painted, restored sewer line will last for another year.

Application of plastic structures

In private homes, when installing systems for removing air and various types of odors, they mainly use plastic vent pipes. They can be round or .

Risers used as fan risers are produced different sizes. When installing an exhaust or supply ventilation fans are in demand plastic pipes with a diameter from 50 to 110 mm and a length of 3-4 meters.

If the plastic fan pipe in the ceiling is cracked, then it needs to be replaced. Repairing this part of the exhaust or ventilation line will not bring the desired result.

When carrying out this procedure, you should adhere to the sequence of work:

using a hammer drill around the riser, expand the diameter of the hole (at least 2 times);
use a grinder to cut the cracked element of the system approximately in the middle of the height so that it is convenient to remove both pieces;
remove the cracked parts and put a new riser in their place;
seal the hole around the installed element exhaust ventilation both from below in the ceiling and in the upper plane of the ceiling.

It must be said about the presence of flexible plastic fan pipes. To connect them to a solid part of the system, it is recommended to use rubber rings for sealing. For better fit into the socket and complete tightness, they must be coated with silicone before installation. When attaching such a section to the wall, metal clamps are used, which are characterized by increased reliability.

Important! Although silicone is an ideal substance for high-quality sealing, it should be remembered that the next time you dismantle it, you will have to put in a lot of effort to remove it.

Today plastic risers can be purchased at any hardware store or store.

Dimensions

There is no separate part called a fan pipe, regardless of size.

This design includes:

regular tee;
lid or grill;
one or more pipes;
safety valve.

The dimensions of drainage pipes for sewerage, as well as for toilets, depend on the specific conditions of their operation.

The following rules must be followed:

You can use parts from any materials;
The size of the pipes for the exhaust riser, including the length, may vary.

Today, the most popular are plastic fan pipes with diameters from 110 to 50 mm, regardless of other linear dimensions(lengths).

Using a 110x45 ani plast w4220 drain pipe, which can be of different sizes, it is convenient to connect the sewerage system to the toilet outlet. Such a detail will seem to glue the toilet bowl to the sewer riser, which will ensure that there are no leaks in the bathroom. The size of the toilet drain pipe depends on the diameters of the drain, sewer riser, and the distance of these elements to the wall or ceiling.

The diameter of the part must be such that the maximum possible sewer flows do not interfere with its normal functioning. Sometimes ventilation and sewage systems are constructed from risers of different diameters. Then you need to use a special adapter.

There is a catalog where you can select the necessary parameters of parts for arranging an exhaust system.

Important! Perfect option placement of the exhaust riser - the place where the internal and external sewers are connected.

Fan pipe ventilation

Current building regulations state that it is not necessary to install ventilation in one-story houses, since in such dwellings the one-time drains are small. Buildings with two or more floors must be equipped with such systems. This is due to the fact that with the help of such risers communication with environment, which means ventilation processes occur.

Many people ask: “Can the waste pipe be vented? And if so, how to connect the vent pipe to the ventilation?” We will give detailed answers to these and other questions.

When installing a vent pipe, it can and simply must be vented, which is most often done. To carry out such a procedure, you must first build ventilation duct.

Need to anticipate installation check valve.

Its purpose:

prevents the return of drain flows;
prevents rodents from entering the sewer and into the premises;
corrects a sewer pipeline with an incorrectly installed slope;
limits the entry of mechanical impurities into the toilet.

The principle of operation of the device is simple: after cistern water comes out, it is triggered and the liquid enters the sewer system. With the valve closed, from the toilet and sewer unpleasant odors do not spread throughout the rooms, since the device is completely sealed.

Important! Install a check valve immediately after the toilet.

Although everyone is trying to install the exhaust system correctly, you can still smell an unpleasant odor from the sewer system in our houses and apartments.

Sometimes odors from the exhaust pipe are blown into the ventilation, since these two channels are located next to each other. To get rid of unpleasant odors, you need to install an aerator at the upper end of the riser. Thanks to this vacuum valve, the system will function perfectly.

Output to the roof

Not everyone knows how to ventilate the roof. This must be done, since the ventilation system in the attic cannot end. The drainage pipe must have access to the roof so that there is a connection with the street and the atmosphere. If the sewer is led to the attic, then all the unpleasant odors will be concentrated there. When the hood does not reach the roof, it is due to increased humidity in attic Mold will begin to appear, which will cause a lot of harm to the entire home. The vent pipe is mounted as on the roof multi-storey building, and one-story.

What to do when the drain pipe on the roof freezes? To prevent it from freezing on the roof, it is necessary to provide insulation around it. The cause of freezing is the formation of condensation, since warm air has the ability to rise up. The result is freezing of the walls with ice, which can lead to the blocking of the exhaust lumen and the cessation of the functioning of the entire system.

The risers are insulated with rolled heat insulators or “shells”, which should be securely fastened.

In some cases, it is impossible to carry out the drainage pipe to the roof. This is not a problem, since you can use horizontal diagram installation of an exhaust system. The end of the ventilation system will not be located on the roof, but will be vented through the wall into the air.

You can buy a roof vent pipe at a construction supermarket.

Important! Regardless of how the drain pipe is routed - onto the roof or through the wall, the system requires a check valve.

In order for ventilation systems to function for a long time and efficiently, when laying pipelines, you must adhere to the above-mentioned norms and rules. Only then will your home not be filled with unpleasant odors, but will constantly feel the flow of fresh air.

About ventilation of concrete septic tanks

For sewerage on their territory, each owner tries to make a two-chamber concrete septic tank. These containers must be ventilated not only to eliminate unpleasant odors. If you correctly design and build a ventilation system in a septic tank, then you will make the living of your family and residents of neighboring houses safe, comfortable, and enjoyable. You need to take care not only of yourself, but also respect your neighbors.

Such a structure is a habitat for bacteria that can quickly process organic waste coming from the sewer system. As a result, dirty wastewater turns into clean water and il. This biological-chemical process is accompanied by the release large quantity gas, which not only smells unpleasant, but can cause an explosion if a spark hits it. Conclusion: high-quality ventilation of a two-chamber concrete septic tank without a drain pipe it is impossible. For the full functioning of a conventional septic tank, it is also necessary to provide ventilation.

Video

To communicate the sewer system with the atmosphere and ensure its ventilation during the construction of communications in residential buildings And public buildings a sewer pipe is used.

Wastewater flowing down a vertical riser creates a vacuum in the pipes, which is partially compensated by the remaining water in the siphons. However, if a one-time powerful drain occurs, the wastewater, when moving downwards, forms a vacuum in the sewerage system and causes the emptying of all siphons. This, in turn, leads to the penetration of unpleasant odors from the depths of the sewer into the premises.

This problem is very real and it causes a lot of inconvenience and discomfort. Installing a vent pipe will help solve it, you can learn about it from our article.

Application of fan pipes

In accordance with current building regulations, the construction of a sewer system without including a sewer pipe in the design is possible if cottage. This is explained by the small number of one-time drains.

However, even in low-rise buildings, the need to install a drain pipe sometimes arises. This occurs in cases of a one-time drain of a large volume, when the cross-section of the vertical riser is blocked by the flow of wastewater by 100%, for example, when using a bathtub and toilet at the same time.

As a rule, the toilet is mounted on a sewer pipe with a diameter of 110 mm, the cross-section of the drain hole cistern usually 70 mm. A pipe with a diameter of 50 mm is supplied to the bathroom, which is then connected to the riser. Thus, the siphon cross-section does not exceed 110 mm. It turns out that when operating one toilet or only a bathtub inner diameter The riser is not completely blocked.

Sinks, washbasins and Appliances connected to the sewer (dishwasher or washing machine etc.) are also not able to significantly affect the volume of a one-time flush, so a drain pipe for the toilet in this case can be installed at will.

If the house has several bathrooms, which are used simultaneously by different family members, the installation of a drain pipe is mandatory.

The construction of a sewer system with waste pipes is advisable in the following cases:

installation in a private house of a sewer riser with a diameter of 50 mm or less;
the presence of two or more floors, each of which has sanitary facilities;
if the house has a swimming pool and other plumbing equipment that generates powerful wastewater.

Installation

Installation of drain pipes

If you are installing a vent pipe yourself, follow the basic rules:

when purchasing building materials make sure that the sections of the sewer riser and the waste pipe coincide; the optimal diameter of the drain pipe (as well as the riser) is 110 mm;
the outer section of the riser should be placed in such a place that the sewer “aromas” from it quickly and easily dissipate in the atmosphere;
The starting point of the sewer system should be located in a heated room, but the final point, on the contrary, should be in a cold room. This provides the necessary difference in temperature and pressure, thanks to which unpleasant odors are removed from the outside of the house.

Pro tip: The sewer pipe is an actual continuation of the main sewer riser and can be made independently from a pipe intended for sewerage of the appropriate diameter.

Unpleasant odors in bathrooms appear due to the fact that siphons of insufficient volume are installed on sanitary fixtures. In small siphons, the remaining water dries out quickly (in 3-5 days, if you don’t use plumbing), which allows odors from the sewer to freely enter the room. Sometimes installing siphons with a larger capacity is not practical, then replacing the drain pipes in the apartment is required.

If the sewage system of a residential building has such a component as plastic drain pipes, the problem is solved as follows:

the air in the sewer riser, rising up and falling outside the pipes, creates a vacuum in the sewer system;
when siphons are dehydrated, air from the room leaks into the sewer, and not vice versa;
the air remains fresh, without an unpleasant odor, even after prolonged non-use of the plumbing fixtures.

Ventilation pipe outlet to the roof

To household tasks house sewerage refers to the transportation of wastewater from the building to an external sewer system. For her efficient work good ventilation is needed, which is provided by risers equipped with fan pipes.

Pro tip: The vertical vent riser must lead to the roof. It is strictly forbidden to place the output in the attic.

To properly install a drain pipe, you must adhere to the following principles:

ensuring the outlet of the vent pipe to the roof, it is provided optimal height– 50 cm; if the roof is used for any purpose and is actively used, the riser outlet should not be less than 3 m;
a sewer pipe of 110 mm in diameter is connected to a sewer riser of equal cross-section;
One drain pipe can connect several risers at once;
It is prohibited to organize the outlet of a riser equipped with a waste pipe together with ventilation system or stove chimneys;
The exhaust pipe outlet, located above the roof, is made at a distance of 4 m or more in the horizontal direction from openable windows, balconies, etc.

Connection of several risers with one drain pipe: 1 - oblique tee; 2 - 45 degree elbow; 3 - straight knee; 4 - straight tee.

A sewer riser leading to the roof does not require the installation of any additional exhaust devices (for example, a deflector, a weather vane). Moreover, the use of these devices can lead to the release of condensation in the system, which, when frozen, will block the outlet openings.

Fan pipes are used to ventilate the sewer system: the sizes of such products vary, but the most common is the use of 110 mm pipes.

Check valve for drain pipe

Installation of the vent pipe is simple: installation is carried out in a channel pre-designed in the ventilation. If ventilation diagram contains a small number of ventilated risers; the fan pipe can be discharged horizontally through the nearest wall. Plus it won't do any harm. interior design premises.

Fan pipes must be equipped with a check valve. It corrects the situation when the sewer pipe has an incorrect slope, and also protects the home sewer system from:

returning wastewater back to plumbing fixtures;
rodent intrusion;
ingress of mechanical impurities.

The valve can be mounted not only inside the drain pipe, but also outside. Internal installation involves preliminary thorough cleaning and degreasing of the pipe, followed by installation of a special insert. The check valve for waste pipes is sold separately from this insert. It is placed in the opposite direction of movement of the drains, and its petals should bend towards the plumbing.

When laying a drain pipe with a working diameter of 110 mm, an adapter will be required to install a check valve. If fan pipes are connected to gray pipes with a sawed-off socket, the valve is mounted in the pipe.

Pro tip: When installing a check valve, experts do not recommend using silicone or any other lubricants, even those intended for sewage systems. Carry out all installation operations on dry surfaces.

Internal wastewater from the building must be regularly transported to external system sewerage system, which is required for its operation. Its operation is ensured thanks to special risers, which are equipped with fan pipes. When installing a sewer riser onto the roof, there is no need to install additional exhaust devices like a deflector and weather vane. You will need to connect several risers using one fan pipeline. Prepare the ventilation duct in advance. First connect the oblique tee, then the 45 degree elbow, then the elbow and then the straight tee.

Place the vent pipe at a height of 30 to 50 cm from the ridge if the roof is not in constant use. If the roof is constantly used, for example, as a summer terrace, then it is necessary to draw a height of three meters.
If your home has two or three risers installed in the sewer system, equip them with one ventilation pipe.
When installing the ventilation pipeline, the distance from windows and balconies must be at least 4 m.

Do not route the ventilation fan pipeline under the roof overhang; it can be damaged by snow and rain that falls on the roof and begins to slide and fall.

The issue of arranging the sewer system of a private house is quite acute, because the cost of a mistake can be quite high. If there are deficiencies in the design and installation of sewage systems, there will always be an unpleasant odor inside the room, which brings not only discomfort, but also real harm household health.

Thinking through the schemes sewer systems, many homeowners wonder what a vent pipe is and what its real use is. Professional plumbers answer this question unequivocally; they consider it an essential element of the septic tank, which they cannot do without. In this article we will tell you how to install a drain pipe and what its functions are.

What it is?

A sewer pipe is an element of a communication system that communicates between the sewer riser and the atmosphere. Wastewater moves along the riser strictly from top to bottom, so when several devices located on different floors are used simultaneously, a vacuum effect occurs inside the riser. A vacuum appears in the system, due to which water is sucked in and the water seal dries out. In the absence of a water plug, unpleasant odors from the sewer penetrate into the room, which greatly reduces the comfort of its use.

The process of vacuum formation inside the sewer riser is associated with the cross-section of the riser and the volume of wastewater. Many Appliances They use sewers to dispose of wastewater - toilet, bathtub, sink, washing machine. The maximum volume of simultaneous drainage is at the bathtub, but individually each of the devices cannot completely fill the sewer system. The situation changes when several devices are used simultaneously, and wastewater fills the entire volume of the riser. In this case, due to the rarefaction in the riser, water is sucked out of the siphon with a squelching sound, and an unpleasant odor penetrates into the room.

Important! Installation of vent pipes is not carried out in all houses. The need to install this element is determined by the number of floors of the house, the number of devices that drain into the sewer and the frequency of use, as well as the diameter of the sewer riser.

Functions

The drain pipe is a connecting element between the sewer riser and the atmosphere, where foul fumes are removed. It is connected to the sewer system at the lowest point of rigidity and discharged vertically through a ventilation duct located near the roof ridge. Therefore, for one-story, small or seasonally used houses, the installation of waste pipes is optional. Although this element of the sewer system performs the following functions:

Note! Fan valve for sewerage or as it is also called an air valve. It is placed on the main axis of the sewer riser on the upper floors of the house, where dirt, splashes, and dust will not reach the membrane of the device.

With a sudden simultaneous discharge into the sewer, wastewater carries with it up to 25 liters of air, which is why a state close to a vacuum is created in the system. At this moment, the fan drain sucks air from the room to reduce the vacuum in the pipe, while the water seal is maintained and odors do not penetrate into the room.

How can I determine if installation is required?

The drain pipe is an optional, but highly desirable element of the sewer system, which perfectly stabilizes its operation. It is considered that installation is necessary for all houses with a height of more than one floor. However, when designing a sewer system, it is important to take into account other minor factors:

Remember that the amount of wastewater is affected not only by the number of plumbing fixtures, but also by the intensity of their use. If the building has two bathrooms located above each other, but only one family lives in it, then it is unlikely that a drain pipe will be needed, but it certainly will not be superfluous.

Types of pipes

When designing sewer systems for private houses, it is necessary to take into account many factors, ranging from the number of floors and devices that drain water into the riser, ending with the diameter of the pipes. Fan pipes are divided into categories based on shape, diameter and material used to make them. The diameter of the drain pipe depends on the diameter of the sewer riser. Based on the material, they are divided into the following types:

Please note! When installing or replacing a drain pipe, you can connect cast iron sections with plastic ones; the main thing is to choose the correct diameter of the pipes so that in no case is there a reduction in the cross-section in the system.

Installation requirements

Installation and replacement of a drain pipe is a rather complex plumbing operation, which definitely requires a project and experience. In most cases, it is laid strictly vertically and discharged through a ventilation duct in the roof. In rare cases, it is possible to route the fan pipe horizontally through the walls of the upper floors. The following requirements apply to the installation of this element:

Remember that, in essence, drain pipes are a continuation of the sewer riser, so they are made from special sewer pipes. If the bottom of the pipe passes through unheated room, it needs to be insulated.