The sewage system of a private house consists of internal and external pipelines. Installation of the internal part of the drainage system is complex and requires professionalism and the use of special equipment. In areas where there are outbuildings, plantings or roadbed, special equipment is used and sewer pipes are laid using the horizontal puncture method.
When choosing pipes, you need to consider:
- ability to cope well main task– drainage, do not allow small debris to cling to the internal walls and accumulate, forming blockages;
- resistance to aggressive substances contained in wastewater and soil;
- strength that does not allow the pipes to deform under the weight of the soil laid on top of the pipeline.
Sewage pipes have their advantages and disadvantages, which vary depending on the material from which they are made:
| Pipe material | Advantages | Flaws |
|---|---|---|
| cast iron | durability, | heavy weight, difficulty in transportation and installation, roughness of the internal surface, high cost |
| steel | resistance to mechanical stress, smooth internal walls | instability to moisture, susceptibility to corrosion |
| asbestos cement | durability, lightness, low cost | instability to mechanical stress, roughness of the internal surface |
| polyethylene | low cost, ease of transportation and installation, durability, resistance to chemicals, smooth internal surface | withstandable temperature - up to 50 degrees, instability to ultraviolet radiation |
| polypropylene | withstandable temperature - up to 80 degrees | low rigidity, susceptibility to deformation when mechanical impact |
| polyvinyl chloride | variety of types and sizes, ease of transportation and installation, smooth inner surface, wear resistance | withstandable temperature – up to 40 degrees |
Pipes made of polymers, in addition, can be smooth-walled or corrugated: the former are cheaper, the latter are more durable and elastic.
There are also insulated pipes and pipes with a built-in heating cable - they are used when installing shallow sewers.
How to lay sewer pipes in the ground
Installation of external sewerage into the ground occurs in three stages:
- Preparation of trenches.
- Pipeline installation.
- Backfilling.
Digging a trench
Before digging trenches for laying sewers, calculate the network configuration and determine:
- Optimal geometric shape pipeline: the most efficient and easiest to maintain will be a pipeline with minimum quantity corners and branches, if possible - the pipeline is led in a straight line from the house to the place of wastewater discharge. To avoid obstacles, it is permissible to turn the pipeline at an angle of 30-45 degrees. Right angles in sewer network are unacceptable due to the increased pressure of wastewater on the walls of the pipeline and the increased likelihood of blockages.
- The depth of the trenches, which allows maintaining the operability of the channels in winter period: below the depth of soil freezing per pipe diameter plus 15-20 cm per sand cushion. The minimum permissible trench depth is 0.5 m, the optimal varies from 2 m to southern regions Russia up to 3.5 m – in the northern regions.
- Angle of inclination ensuring free flow of wastewater: usually, a slope of 1-2 cm per meter of pipeline is sufficient;
- Trench width: 40 cm is added to the pipe diameter; for large depths and pipe diameters greater than 20 cm, the trench width is increased for ease of installation.
Underground sewerage includes a whole complex of engineering structures, equipment, as well as sanitary cleaning work that ensures their uninterrupted operation. Sewage is an integral part of water supply and drainage systems.
All wastewater is transported through the system to a settling tank. The system consists of two independent branches, for domestic drainage and for drainage of atmospheric water (storm drainage). It is customary for them to be transported through separate pipelines.
Pad underground sewer, is the most expensive, both in terms of time and material costs. When laying out the system, it is necessary to take into account many criteria that will ensure long-term and uninterrupted operation. One of the criteria is pipe insulation. If the insulation is not done well, the pipes may freeze in severe frost and the drainage will stop. The use of plastic pipes is less dangerous due to the fact that they are not afraid of deformation, since cast iron pipes will not burst.
The depth of laying the external sewer pipe in the ground depends on the depth of soil freezing in your area and is calculated 30 cm deeper than this depth. It is customary to lay underground sewerage to a depth of at least 70cm, and for areas with low winter temperatures, this depth is set to at least 1.2m. Today, the industry produces special polypropylene pipes that have good thermal insulation characteristics. The use of thermal insulation can significantly reduce the depth of sewerage in the ground, and, therefore, reduce the cost of installation and subsequent repair and maintenance work.
Light pipe weight
Easy to install.
Minuses:
Soft, easily deformed when pressure increases,
Pipes with thick walls are very expensive,
They become unusable when exposed to sunlight.
Polyethylene pipes
There are smooth and corrugated. The latter, by the way, are more durable.
Pros:
Possibility of laying pipes to a depth of up to 15 m, since they do not deform under the weight of the soil,
Smooth inner walls
Small mass
Easy installation due to the presence of connectors and tees,
Service life more than 50 years.
Minuses:
Deforms at temperatures above 65° C,
They become unusable when exposed to sunlight,
Installs only in the ground.
Despite all their advantages, polyethylene pipes have little strength, so their rigidity is increased due to the outer corrugated layer.
Asbestos cement pipes
Such pipes are made from a water mixture of cement and asbestos.
Pros:
Resistant to any chemicals,
Service life up to 100 years,
Easy to install and simply connect to each other,
Small mass
They rarely get clogged.
Minuses:
Very fragile (this must be taken into account when purchasing and carefully inspect the pipes for chips and cracks),
Difficult transportation, again, due to fragility.
These two disadvantages overshadow all the advantages of such pipes, so they are now practically not used.
Ceramic pipes
Ceramic pipes were used even before our era, but even now they are also used in sewer construction.
Pros:
Easily tolerate temperature changes,
Resistant to any chemicals, even the most caustic ones,
Easy to install,
They practically do not clog due to the slight roughness of the internal walls.
Minuses:
Very fragile and this makes their installation and delivery difficult,
Small length, which leads to a large number of joints between them.
Because of its fragility ceramic pipes have practically disappeared from the market because they are difficult to use.
Pipe diameter selection
When choosing the diameter of a sewer pipe, you need to pay attention to both the internal and external diameters.
For sewerage of a small private house, a pipe with a standard diameter of 110 mm is suitable. When combining several sewers into one network, the diameter of the pipe must increase. Pipes for polyurethane foam use the largest diameter size.
In most cases, pipes with round. But there are cases when pipes with a rectangular or elliptical cross-section are used.
Rectangular pipes can be installed if the sewage system is located at a depth of up to 1 meter, and ellipsoidal ones in the case where soil or drainage creates very strong pressure on the pipes.
It should also be remembered that if sewer system If the pipe is located shallow, it must be insulated, otherwise the pipes may burst at sub-zero temperatures.
Methods for connecting sewer pipes
There are three connection methods:
1) welding- the most difficult method, as it requires certain skills and special equipment. Used to connect plastic and metal pipes. In case of repair, such connections create some difficulties;
2) bell-shaped- a thin section of the pipe is inserted into the wide end of the second pipe (socket), rubber seals and sealants are used for tightness, and tow is added at the end;
3) coupling (flange, socketless)- the two pipes are pressed tightly against each other with their cuts, a rubber cuff is placed on top and tightened with a clamp. This is the most convenient method for sewer repair.
From all this we can conclude: before choosing a particular type of pipe, it is necessary to analyze all the factors for a specific situation in order to avoid problems in the future. For example, calculate the slope of a sewer pipe depending on the site.
Video: All about sewer installation
Basically, PVC products are used for the construction of modern sewers, which have many advantages and disadvantages. But pipes of other materials, which have their own characteristics, can be used. Due to the fact that the consumer is primarily interested in which pipe to use for underground sewerage in accordance with his budget, we will consider suitable and affordable varieties.
Characteristics of plastic products
Preparing trenches for laying sewer pipes
Pipelines with standard sizes are available for sale. Their diameter is determined by GOSTs, that is, pipes can have sizes of 10, 50, 90, 110, 300 and 160 mm. There are also products of large diameters, but they are not suitable for private construction.
Basically, the connection of plastic pipes is made using a similar technology by inserting into a fitting or other pipeline. Fittings include tees, angles, crosses, bends, revisions, plugs.
All plastic products are light weight, density 0.95-1.4 g/cm3, and differ in dielectric properties. Pipes have a slippery and smooth surface, which protects them from deposits.
PVC pipes are resistant to alkalis, acids and mineral oils. They are characterized by long-term operation, but at a temperature of 70 degrees their strength begins to lose. Therefore they are not suitable for equipment industrial sewerage. Also, PVC pipes are hard and slightly brittle and have low sound insulation.
Polyethylene pipes differ from PVC products in being more slippery and pliable. Polyethylene is characterized by better noise absorption, resistance to mechanical damage, and better chemical resistance to acids, biomass and alkalis. Polyethylene can be used to produce corrugated products intended for underground installation, resistant to pressure and soil displacement. But there is a risk of pipe deformation when pouring hot water.
installation of inspection wells
A more durable material for the production of pressure pipes is polypropylene. Its softening temperature reaches 140 ºС, melting temperature – 175 degrees. Polypropylene sewerage is resistant to boiling water, but at temperatures below 5 ºС the material becomes brittle. Because of this, pipelines need to be laid underground or thermally insulated. Polypropylene is highly resistant to wear, so it can be used for draining wastewater with a high content of solid abrasive elements.
Characteristics of products made of cast iron and other materials
Cast iron pipes can often be found in old buildings, but they are no longer recommended for new buildings. The only advantage of cast iron pipes over plastic ones is their high noise absorption. Otherwise, they are characterized by large mass, high cost, and complex installation. They can be used for laying under roads due to their high strength. If you have chosen these pipes, then it is better to choose products treated with an anti-corrosion compound.
When constructing a sewer system in cities and enterprises, ceramic, reinforced concrete and asbestos-cement pipelines can be used. But they are not used in domestic conditions.
Which pipeline is better to choose for internal sewerage?
Mostly, home owners refuse cast iron products due to difficult installation and large mass, preferring their plastic counterparts. Plastic pipelines can be laid independently without specialists. In addition, plastic is characterized by resistance to aggressive environmental influences and durability.
For laying internal sewerage It is better to choose polyvinyl chloride products that are resistant to wastewater at different temperatures. The pipes withstand freezing and soil pressure, do not form cracks and there is no loss of shape. In addition, plastic structures are sealed and corrosion resistant.
The rules for laying sewers have one condition that must be strictly adhered to - avoid sudden changes in levels and turns. When laying sewerage, you must comply regulatory documentation SNiP P-G.3-62.
security correct angle sewer pipe slope
Selecting the diameter of the sewer pipeline
If you study SNiP 2.04.01-85, it describes in detail the calculation for choosing the size of pipes for sewerage. It turns out that the suitable diameter of the sewer pipe in a private house is 50 mm, to which plumbing equipment for the kitchen and bath can be installed. For the riser and toilet, structures with a diameter of more than 10 cm are chosen, since in such places a large water flow is created.
The toilet should be mounted to the riser via a separate pipeline. There is no need to connect products with a smaller size to its drain, otherwise the flow may block the cross-section of the pipeline and create a vacuum in the connected pipe. Because of this, the siphons of other equipment may become dry.
As a result of this, the optimal choice would be pipes with a diameter of 50 mm for horizontal surfaces that go to the kitchen or bathroom, and for the riser and toilet - 110 mm.
For individual drain points (shower, bidet, sink) you can use smaller pipe diameters of 22-40 mm. Here rubber cuffs or couplings with a transitional size are used.
For apartment buildings (with 5 floors), pipes with a diameter of 100 mm are suitable, and in buildings with more floors, pipelines larger than 150 mm should be laid.
Pipes connecting several risers with access to a sewer well can be up to 20 cm in size.
Features of sewerage installation
In addition to choosing the appropriate pipe size, you should consider the details of laying the sewer system. The diameter of the horizontal pipeline cannot be larger than the riser for drainage. Installation of horizontal connections is carried out with oblique angles and tees. Right angles are allowed only when connecting the riser to a horizontal section.
At sewer bends, inspections are installed - openings with covers for cleaning pipes.
First, a system design is created, which takes into account the following factors:
- soil composition;
- mechanical loads on the sewer system;
- soil freezing depth;
- depth of groundwater.
The project reflects the placement of all drain points in the house, on the territory, the location of the water intake point, and the septic tank. The turning points, sewer pipe installation lines, and inspection installation are also indicated.
At this stage, the material used, the need for thermal insulation, drainage system and the number of adapters are determined. For bends and adapters, a slope of 45ºC must be created; from the pipe to the septic tank the slope must be at least 2 cm per linear meter. If the sewerage system is laid above the freezing point of the soil, it is insulated and the connections are sealed with sealant or silicone.
laying sewer pipes at the foundation stage
Carrying out installation work
Do-it-yourself installation of sewer pipes begins after marking the system on the territory, calculating the installation depth, and selecting pipes required diameter, cleaning facility.
Preparatory work involves digging a pit for a septic tank or cesspool, after which a trench is dug for pipe installation. They need to be dug 20 cm lower than the planned level of laying sewer elements.
Plastic is resistant to low temperatures, but to prevent water from freezing in such pipes, they are wrapped with thermal insulation and covered with a dry mixture of cement and sand in a ratio of 1/3.
laying a drain pipe to a sewer septic tank
In order for the sewer system to work properly, the slope of the pipes specified in the project must be observed. The depth of the trench on a flat surface near the house should be less than near the treatment plant. With a natural slope from the building to the septic tank, a trench is dug with a uniform depth along the entire length of the pipes.
On a steep slope, it is better to divide the sewage system into sections with different levels where drop-off or distribution wells are installed.
The bottom of the trench is compacted and covered with a crushed stone or sand layer. Pipes can be laid in a trench to any depth. When placed high groundwater and deep freezing of the soil, a buried trench is dug into which the pipeline is laid high. When the water level is low, it is placed near the bottom or in the center of the trench.
Before laying pipes in trenches, you should check the inside for cleanliness. Laying of the pipeline begins from the drain points in the house, after which the sewer is installed towards the treatment plant and connected to the remaining branches of the street drain.
You should remember to install pipes using an O-ring or silicone grease, installing them in areas of turns and branches of auditors. After carefully laying the pipes, they are carefully wrapped with thermal insulation. Inspection wells, auditors and a ventilation pipe are installed near the house. If the pipeline is long, it will be necessary to create 1 or 2 ventilation pipes.
Before backfilling the system, a control drain should be performed, which will reflect the quality of the pipe installation.
At the end of all work, the sewer pipes are first filled with a mixture of sand and cement to a depth of 15 cm, and then with soil. Inspection wells and revisions are installed 20 cm above the ground level.
Additionally, you can familiarize yourself with video instructions on laying a sewer system, which you can do yourself if you follow the appropriate rules.
Any type of human activity has a colossal impact on the environment. Especially if this is an industrial production, the waste from which poses a huge danger.
Enterprise wastewater, which has a structure modified by physical or chemical methods and a number of impurities, can cause serious damage to the environment. That is why the problem of industrial waste disposal has been relevant since the advent of industrial enterprises. At the moment, the most effective solution to this problem is the installation of a sewer network. Two types of sewerage can be used as a local sewerage system at a production facility: external and underground.
External sewerage is a complex of structures and systems located outside the enterprise building. It is a network of sewer pipes located on overpasses (supports) and laid to cleaning devices. Underground sewerage includes a set of engineering systems and equipment, sewer pipes to which are laid in dug trenches or punctures.
Installation of external sewerage networks
Ground installation is carried out in most cases in areas with permafrost soils. The pipes are located on channels and trays that are above ground or partially grounded. The method of installing such a sewer network depends mainly on the conditions of the given facility.
Not very aesthetic appearance is the main disadvantage of external sewerage
For installation of pipes with small and medium diameters, steel or reinforced concrete masts and supports are used, for pipes with large diameters - reinforced concrete overpasses. Thermal extensions of the sewerage system are equipped with bent expansion joints. Maintenance is carried out from special sites. If necessary, it is possible to install special bridges for crossing.
In terms of cost, as well as the price of installation and maintenance, external sewerage is more profitable than underground sewerage, but it spoils the aesthetic impression and is not always appropriate.
Underground sewerage installation
Underground sewerage installation somewhat different. There are two types of laying a sewer network underground: channelless (installation of pipes directly in the ground) and channel (laying in special channels).
The first method has a lower cost and is completed much faster than the second. The safety of the pipes is ensured by special insulation and thickening of the shell. The second provides high degree protecting the pipe from mechanical damage and environmental influences. In addition, the channels used in this method are also divided into several types:
- Pass-through (large number of pipes)
- Semi-bore (numerous pipe intersections)
- Impenetrable (many pipes are not large diameter)
Underground sewerage used much more often than aboveground. It provides good pipe protection, is more compact, and preserves the appearance of the environment. However, it also costs much more.
It is unlikely that you will be able to save money on installing an underground sewer system
Aboveground sewerage ideal when crossing difficult terrain or water obstacles. In addition, it is very popular in areas with frozen soil that does not allow underground installation.
Which method is better is a moot point. It all depends on the purpose of the sewer, environmental conditions, aesthetics, convenience and a number of other factors. However, each type has undoubted advantages, which, if used correctly, will serve uninterruptedly for many years.
Even with precise planning of the route for laying an external or internal sewer pipeline, it is not always possible to avoid sharp turns and bends. Most often you have to decide how to bend a sewer pipe when installing in hard to reach places: in niches and under plumbing siphons, when exiting a wall or ceiling, when it is necessary to bypass a ledge or corner. There are two options for solving the problem:
- Use special ready-made bends - fittings and adapters, installing them at the point of change of direction with a special sealant or seal.
Ready-made solutions for creating any complex shape
- Trying to bend the product at the planned bending point is an unreliable, labor-intensive and time-consuming method for preparation.
Materials for manufacturing sewer pipes and features of deformations: which pipes can be bent
Mechanical bending is performed only when it is not possible to change the trajectory; or the pipeline is of non-standard diameter, and it is impossible to select a suitable adapter; if it is necessary to leave a solid bent piece for aesthetic reasons. Not all materials can be bent without the risk of damage, and the result of manipulation depends on experience, skills and the correct use of special tools.
Complex bending of a metal product
Before making a decision, analyze the characteristics:
- Product diameter and material of manufacture.
- Wall thickness.
- Required radius and rotation angle.
Plastic pipeline: characteristics of polymer materials
Most sewer systems collect from lungs plastic structures. Polymer products are produced in all possible standard sizes, with different characteristics for installation indoors and outdoors. Turns, corners and bends can be assembled yourself in a couple of minutes from ready-made auxiliary parts: adapters, elbows, tees and fittings. The possibility of mechanical bending is limited.
Pipelines made of orange polymers intended for laying in the ground are made of frost-resistant thick-walled material. Such products cannot be deformed. The second factor that influences how a turn is performed is diameter. When the radius changes, the shape of the internal section is deformed: instead of a circle, an oval is created. To prevent damage to the pipe, the volume of deformation should not exceed 8% of internal diameter. Manually, or using mechanical devices, you can change the shape of only molded products for internal wiring(gray or white) small diameter - up to 50 - 60 mm.
How to bend a plastic sewer pipe? The choice of method depends on the characteristics of the main polymer compositions used in production:
- Polyethylene. The most pliable material for giving complex shapes. It is rarely used in the manufacture of sewer parts, since it has significant shortcomings: Insufficiently smooth surface, low strength and poor heat resistance. You can form the required bending radius in 2 ways: cold and hot.
Unreliable, but easily bendable, polyethylene
- PVC. Products made of polyvinyl chloride, which are used for sewage, have different wall thicknesses depending on the diameter. The material is quite fragile, so it cannot be changed without heating. Only small-diameter PVC sewer pipes are bent using hot method– PVC has enough low temperature melting. To change the shape of large-diameter products, special electromechanical industrial equipment is used.
- Polypropylene. The hardest and durable material for sewerage. The high melting point is one of the reasons why it is difficult to bend such a sewer pipe. Craftsmen use the liquid heating method. Cold mechanical bending can be used to shape a bend with a small radius.
Bend polypropylene pipe
Important! Regardless of the chosen method of bending and the material used to make the pipe, it should be remembered that during the deformation process, the material along the upper edge becomes thinner, stretching, and along the lower edge it becomes denser. It is impossible to guarantee the tightness of the product at the deformation site. Therefore, too large a bend radius should be avoided.
Metal pipes: is it possible and how to form a bend?
For home sewer installations, metal is rarely used as the main material for pipes due to the high cost and complex process of connections and installation. Metal sections are installed only as a design solutions for connecting plumbing open method without decorative screens.
Metal pipes with bend
Basic materials:
- Copper.
- Stainless steel.
- Steel alloys.
- Combination of inner metal layer and polymer coating
Metal bends easier than plastic
Homemade metal pipes can be bent using cold or hot bending methods. Metal is easier to bend, does not lose its tightness, and does not crack at the point of deformation.
You can change the shape of an all-metal pipe or with an alloy base in 2 ways:
- Cold mechanical.
- Combined: mechanical, with short-term heating.
If it is necessary to make a turn on a long section, you will have to use welding: a bend is formed on a short section of the required diameter from an identical material, and the turn is welded into the pipe cut at the point of the turn.
Cold bending method: instructions and limitations
Manual cold method bending is suitable for changing the shape of metal and metal-plastic thin-walled pipes with a diameter of up to 32 mm. To bend such an internal sewer pipe, you will need:
- Special spring selected according to the inner diameter.
Spring: allows minimal deformation of the internal lumen
- If you don’t have time to search and buy a spring, you can use sand. Additionally, you will have to make plugs for the ends - from plastic, wood, cork.
- Factory blanks are used as a template to create the required radius, or glued from cut-out ones are used. Chipboard sheets cones.
Thin sewer pipes can be bent without special clamps. For products made of hard alloys or thick-walled pipes, special equipment is used: hydraulic machines (bending products up to 60 mm), electromechanical machines (for parts with a diameter of 60 mm).
Professional machine for creating complex shapes
The spring is placed inside the pipe section. Both ends of the spring must be free. If the diameter of the spring is smaller than the diameter of the pipe, the ends can be secured with clamps. After installing the pipe bender, they begin to slowly bend the product.
You need to bend the pipe gradually - the material (especially metal-plastic and polyethylene) returns to its previous position, so a larger radius is created. Thin sections are bent by hand; for products of larger diameter, a clamp or template is used.
High temperature bending: features of the hot bending method
To give the required form non-standard plastic pipe, you should prepare:
- Spring to maintain the inner diameter, or sand.
- Construction hair dryer: it is advisable to buy equipment with multi-stage temperature control so as not to overheat the plastic.
- Forming machine: a board or piece of chipboard panel with clamps attached along the planned shape of the pipe.
Homemade machine
- Blanks along the radius from bars.
Bars for the bend template
Instructions: bending pipe step by step
How to bend without damaging the walls sewer PVC pipe? Before you begin, you should fill the internal gap. A spring or a thick-walled metal pipe is inserted inside the pipe. Some craftsmen advise pouring sand and soldering or capping the edges.
But during heating, grains of sand can stick to the inner walls, which is why dirt will constantly accumulate at the bend.
After filling, the pipe is fixed on the machine with clamps. If possible, you need to put on a silicone molding sleeve so that the walls are not scratched during operation.
After attaching to the machine, radius templates are installed in the planned locations.
Carefully heat the walls along the entire diameter with a hairdryer, bending the pipe according to the template. It is very important not to overheat the surface - PVC melts already at 130 o, polypropylene - at 150 o. Bending must be done very slowly so that sagging and folds do not form on the lower edge of the bend.
Bent pipe must be left in a fixed state until completely cooled. Only after this can you check whether the resulting bend corresponds to the planned one.
Result: how to check the quality and integrity of the fold
The quality of the work can be assessed immediately: if the resulting bend does not visually change the shape of the section, the walls are smooth, without folds or cracks, then everything was done correctly.
Ideal Radius PVC pipes
If the walls have melted due to heating, become significantly thinner, and there are pronounced folds on the lower edge, then such a pipe will have to be thrown away. Irregularities on the inner surface and severe deformation of the section are the reason that plaque will accumulate inside the bend, which will lead to clogging.
Unsuccessful attempt
You can check the tightness of the area by filling the pipe with water. But it is impossible to accurately predict how long a bent plastic sewer pipe will remain sealed. As the pressure inside the system increases, the thinned walls may crack, and microcracks will appear over time.
An alternative to mechanical action: how to bend a pipe
It is better to assemble complex areas from factory parts. Finished products are sealed, have an ideal diameter, and are equipped with insulating gaskets. Even a person without training can assemble a bend of the most complex shape.
Ready-made parts for assembling a pipeline of complex shape
Alternative to mechanical bending:
- Fitting.
- Corrugated flexible hoses.
Flexible sewer pipes: application
Installing a corrugated hose is justified if you need to install it in tight niches - under a bathtub, washbasin. It is also advisable to mount plums from corrugated material for household appliances in places where it is not possible to lay a rigid pipeline. Advantages: low cost and ease of installation. The main material of manufacture is PVC.
The disadvantage of flexible sewer hoses is the presence of ribs on the walls. Plaque quickly accumulates on the folds of the corrugation, and threads cling to the protrusions. Corrugated areas are the most common places for blockages to form and the main reason unpleasant odor.
Large diameter bends
To avoid problems with flexible wiring, craftsmen recommend installing removable fasteners - clamps instead of sealant. In this case, you can easily disconnect the hose for cleaning or replacement.
Connections and bends for thick-walled sewer pipes
Complex distribution of prefabricated pipelines
When planning a home sewer system, it is better to provide alternative options bypassing the ledges. To form complex structures pipelines are selected:
- Elbows with a standard angle of inclination to ensure the correct flow rate inside the bend.
- Adapters and turns - for arranging points of direction change.
- Fittings and inspections - installed at points with the greatest risk of clogging.
An example of arranging a non-standard pipeline in difficult conditions
Definitely, if there is the slightest opportunity to avoid bending sewer pipes, it is worth taking advantage of it. A variety of factory products allows you to find optimal solution even in difficult situations. If it is impossible to install a rigid pipeline, it is better to install a corrugated pipe with the possibility of regular replacement. It is strictly not recommended to bend plastic products large diameter, especially if you plan to install a branch in a screed or under a plasterboard panel - it will be difficult to find and eliminate the leak. Bent plastic pipe It is impossible to repair or seal; the entire section will have to be replaced. If you cannot do without bending, then it is better to entrust the process of bending and installation to a specialist.
The basis of the sewer system is quality pipe. The higher the load on it, the stronger it should be. Nice pipe for drainage in the ground it lasts for more than 25 years without the risk of clogging, breakdown, or depressurization of the collector. At the same time, temperature indicators do not have a significant effect on it.
How to choose a pipe for underground sewerage
When choosing elements for external sewerage, it is important to consider two important parameters:
- The volume of wastewater that will flow through the collector. The larger it is, the larger the cross-section of the external system will be.
- Level of static and dynamic load on the ground. They mean the intensity of traffic in the area and the pressure of the soil on the collector.
It is good to use a pipe with the smoothest possible surface for underground sewerage. inner surface. This will avoid silting of the system and its blockages.
Material of manufacture and technical characteristics
For the production of external sewerage pipes, four types of materials are used - polymer, cast iron, ceramics and asbestos cement. Each of them has specific specifications and is good when used in certain conditions.
Ceramics
Ceramic sewer pipes
Ceramic “sleeves” have the following positive characteristics:
- high resistance to medium and higher loads;
- big throughput with increasing diameter (up to 600 mm);
- Possibility of installation using the joint/groove system without the use of additional couplings;
- inertness to aggressive waste media.
Ceramic pipes have two significant disadvantages - they are heavy and inconvenient to use. self-installation reservoir, and the relative fragility of the material. If installed carelessly, the wall may crack. More often, such elements are used to install public sewer systems.
Polymer (PPP and HDPE)
Socketed polypropylene pipes
Polypropylene (PPP) and low-density polyethylene (HDPE) are used as polymer materials. In the first case, the positive characteristics of the pipes are as follows:
- high ductility, which reduces the risk of damage to the system during installation;
- good linear stretchability;
- resistance to temperature changes;
- long service life;
- light weight of elements and ease of installation.
However, polypropylene “sleeves” are unsuitable for installing a city sewer, since, according to the maximum cross-section of the sleeve, the system can withstand only average volumes of wastewater.
PVC pipes
HDPE pipes have the following characteristics:
- resistance to temperature changes in the range from -50 to +130 degrees;
- rigidity of the elements due to the corrugated outer structure (the rings act as stiffeners);
- resistance to mechanical loads;
- tensile strength;
- smoothness of the inner walls;
- little weight;
- long service life.
Just like PPP pipes, HDPE elements are not suitable for sewer installations with a large volume of wastewater. Besides direct impact ultraviolet light on a polymer destroys it over time. But this does not apply to external sewerage.
Asbestos cement
Asbestos cement pipes
Such a sewer pipe can be laid in the ground for any volume of wastewater. It is important to choose the correct cross-section of the collector. Asbestos-cement elements have the following advantages:
- resistance to aggressive environments and dynamic/static loads;
- inertness to aggressive components in wastewater;
- smoothness of the inner walls;
- less weight than cast iron or ceramic “sleeves”.
When laying sewers, the weight of an asbestos-cement pipe is often its disadvantage, since such work may not be possible to cope with alone. In addition, the fragility of the material when subjected to a strong mechanical impact on it leads to splitting.
Cast iron
Cast iron sleeves
Main positive points cast iron pipe are:
- resistance to various types loads;
- inertness to low/high temperatures;
- corrosion resistance;
- service life (up to 80 years).
But cast iron also has disadvantages:
- tendency to siltation due to the imperfectly smooth surface of the internal walls;
- weight that makes installation difficult;
- cost of elements.
Diameter of sewer pipes
All pipes for external sewerage, made of various materials, have a specific gradation of sizes/sections:
- Polymers. The diameter of the sewerage elements ranges from 40 to 200 mm. As a rule, elements with a cross section of 40, 50 and 110 mm are used inside the house. The external collector is mounted from pipes of larger cross-section.
- Cast iron. The internal section (DN) starts from 150 mm and reaches a maximum value of 600 mm in increments of 50 mm.
- Asbestos cement. Such elements have a diameter from 75 mm to 600 mm.
All pipes with a diameter of 110 mm or more are intended only for the installation of external sewer networks.
Basic requirements for pipes for sewerage in the ground
In order for the sewer system to operate without failures, it is important that the pipes for the external collector meet the following requirements:
- Durability and long term operation. For private sewerage it ranges from 30 years.
- Inert to aggressive/chemical environments.
- Resistance to temperature changes.
- Maximum smoothness of the inner walls.
Provided the system is correctly installed with a slope towards the wastewater receiver, the sewage system will work properly without the need for expensive repairs. In this case, it is advisable to flush the collector under high pressure at least once every 5 years.
In this article we will talk about which pipes are best to choose for underground sewerage and understand their pros and cons.
So, which pipe is better to choose for underground sewerage?
This question always arises when seeing diversity on the market.
To avoid making a mistake in your choice, you must consider the following factors:
- chemical composition of the discharged waste and its temperature;
- maximum discharge volume;
- the maximum possible decrease in temperature in winter;
- type of soil;
- how deep and at what angle the sewer will be laid.
Pipes in external sewers must be very strong and durable and can withstand negative temperatures well.
This is what guarantees their reliability and longevity of the entire sewerage system.
Materials for sewer pipes
There are several types of materials used in the manufacture of pipes:
- cast iron,
- polyethylene,
- polypropylene,
- ceramics,
- asbestos cement.
Moreover, the last two materials are used extremely rarely. Pipes made of plastic or cast iron are most often used.
Cast iron pipes
Malleable cast iron has many advantages over gray cast iron. Nowadays, socketless pipes made of cast iron (sml) are most often used.
The advantages of such pipes:
Very durable
Will last up to 85 years,
They can easily tolerate negative temperatures.
But there are also disadvantages:
Absolutely not suitable for salty soils,
Very heavy, making installation and delivery difficult
Uneven, rough walls contribute to the gradual clogging of the pipe,
Expensive.
PVC pipes
PVC pipes used for external sewerage are orange.
Pipes gray have thin walls (2.7 mm) and therefore deform under soil pressure. They are used only for internal sewage.
If the laying depth of the pipe is more than two meters and boxes are not used, then in this case it is better to use corrugated pipes.
Pros:
Cheapness,
Easily tolerate temperature changes,
Durability,
Smoothness of the inner walls, which prevents blockages from forming,
Light weight of the pipe, which makes installation easier,
They don't rust.
Minuses:
At a temperature drain water more than 40°C the pipes are deformed,
Used only for non-pressure sewerage,
Suitable for small houses.
There are some differences between pipes from different manufacturers. And this also needs to be taken into account.
In addition, there are three classes of pipe stiffness:
1) S - rigid (used at depths up to 8 m),
2) N - medium hardness (depth up to 6 m),
3) L - light (up to 2 m).
Polypropylene pipes
Pros:
Smooth inner walls
Service life is about 100 years,
Easily tolerate temperatures of 100° C,
Not affected by chemicals
Light pipe weight
Easy to install.
Minuses:
Soft, easily deformed when pressure increases,
Pipes with thick walls are very expensive,
They become unusable when exposed to sunlight.
Polyethylene pipes
There are smooth and corrugated. The latter, by the way, are more durable.
Pros:
Possibility of laying pipes to a depth of up to 15 m, since they do not deform under the weight of the soil,
Smooth inner walls
Small mass
Easy installation due to the presence of connectors and tees,
Service life more than 50 years.
Minuses:
Deforms at temperatures above 65° C,
They become unusable when exposed to sunlight,
Installs only in the ground.
Despite all their advantages, polyethylene pipes have little strength, so their rigidity is increased due to the outer corrugated layer.
Asbestos cement pipes
Such pipes are made from a water mixture of cement and asbestos.
Pros:
Resistant to any chemicals,
Service life up to 100 years,
Easy to install and simply connect to each other,
Small mass
They rarely get clogged.
Minuses:
Very fragile (this must be taken into account when purchasing and carefully inspect the pipes for chips and cracks),
Difficult transportation, again, due to fragility.
These two disadvantages overshadow all the advantages of such pipes, so they are now practically not used.
Ceramic pipes
Ceramic pipes were used even before our era, but even now they are also used in sewer construction.
Pros:
Easily tolerate temperature changes,
Resistant to any chemicals, even the most caustic ones,
Easy to install,
They practically do not clog due to the slight roughness of the internal walls.
Minuses:
Very fragile and this makes their installation and delivery difficult,
Small length, which leads to a large number of joints between them.
Due to their fragility, ceramic pipes have almost disappeared from the market as they are difficult to use.
Pipe diameter selection
When choosing the diameter of a sewer pipe, you need to pay attention to both the internal and external diameters.
For sewerage of a small private house, a pipe with a standard diameter of 110 mm is suitable. When combining several sewers into one network, the diameter of the pipe must increase. Pipes for polyurethane foam use the largest diameter size.
In most cases, pipes with a round cross-section are used. But there are cases when pipes with a rectangular or elliptical cross-section are used.
Rectangular pipes can be installed if the sewage system is located at a depth of up to 1 meter, and ellipsoidal ones in the case where soil or drainage creates very strong pressure on the pipes.
It should also be remembered that if the sewer system is located shallow, then it must be insulated, otherwise you may experience pipe rupture at sub-zero temperatures.
Methods for connecting sewer pipes
There are three connection methods:
1) welding- the most difficult method, as it requires certain skills and special equipment. Used to connect plastic and metal pipes. In case of repair, such connections create some difficulties;
2) bell-shaped- a thin section of the pipe is inserted into the wide end of the second pipe (socket), rubber seals and sealants are used for tightness, and tow is added at the end;
3) coupling (flange, socketless)- the two pipes are pressed tightly against each other with their cuts, a rubber cuff is placed on top and tightened with a clamp. This is the most convenient way during sewer repairs.
From all this we can conclude: before choosing a particular type of pipe, it is necessary to analyze all the factors for a specific situation in order to avoid problems in the future. For example, calculate the slope of a sewer pipe depending on the site.
Video: All about sewer installation
