The device of sewer wells of different types. Modern device of a sewer well: differential, with a riser, plastic Rotary sewer wells
The technology for arranging sewer wells has been worked out to the smallest detail and documented. Building codes prescribe the main series of codes that the work being carried out must comply with. In particular, SNiP has the number 2.04.03-85 and is called “Sewerage. External networks and structures”. The document regulates the placement of different types of structures, the dimensions and requirements for the structures being erected.
Regardless of the purpose, private or public use, the installation of sewer wells must be carried out according to the rules and requirements. For example, a viewing object must be placed in front of the entrance of the local sewerage system to the centralized collector, outside the red building line.
It is especially important to know that, according to SNiP, sewer manholes with pipelines up to 150 mm in size are arranged every 35 m, at 200 - after 50 m of straight-through sections of pipelines. In addition, the installation of structures is indicated for:
- Rotary changes in the water runoff system;
- When changing the diameter of the pipeline or the presence of a slope;
- At the entry points of additional branches.
Documents governing the requirements: for reinforced concrete products - GOST 2080-90, for polymer structures - GOST-R No. 0260760. Manufacturers offer specifications for plastic structures, supplementing existing regulations.
Stone structures can be made of prefabricated, monolithic concrete, reinforced concrete mixtures, bricks. Filtering structures are made of rubble stone. For the manufacture of polymer structures, the use of polyvinyl chloride (PVC), polypropylene (PP), polyethylene of the desired density (PE) is permissible.
Important! Models can be made of combined material.
Dimensional rulers, work on the arrangement of wells
Sewer wells according to SNiP must have the following dimensions:
- Pipelines up to 150 mm in diameter - at least 70 mm;
- Diameter up to 600 mm - from 1000 mm;
- Diameter size up to 700 mm - from 1250 mm;
- Diameter 800-100 mm - from 1500 mm;
- With a diameter of 1500 mm and above and a depth of 3 m and above are subject to individual consideration.
Volumes are not separately regulated, everything must be calculated from the depths and diameters specified on the diagrams. As for the work, the general cycle includes both preparatory actions, installation and completion.
- Breakdown or marking of the territory, according to the rules of construction;
- Cleaning the area from shrubs, vegetation;
- Demolition/relocation of interfering structures. The impossibility of action is stipulated by special standards;
- Preparation and arrangement of the entrance, the road to the construction site.
Arrangement and installation of a typical sewerage structure preparatory work according to SNiP:
- An excerpt of a pit;
- bottom cleaning;
- Reconciliation with the project in terms of the level of laying, the angles of the slopes of the walls;
- For stone structures, the arrangement of a waterproofing bottom layer, as shown by the diagram or plan (layer of at least 20 cm), subsequent tamping.
All preparatory work has been completed and the next stage is installation.
stone wells
The steps and actions are:
- Preparation of the base involves laying a slab or arranging a pillow made of M-50 concrete with a thickness of 100 mm;
- Arrangement of a concrete tray (M-100) reinforced with a steel mesh of the desired shape;
- Seal with concrete and bitumen end openings of the pipeline;
- Creation of an insulating layer of the internal cavity of the rings of the structure;
- The rings are installed only after the tray has gained strength (2-3 days), then the floor slab is laid. The solution used for work - M-50;
- Sealing joints with cement mixture;
- Waterproofing with bitumen;
- Mandatory plastering of the tray with cement, followed by ironing;
- Installation of clay interlocks at the entry point of a pipe/pipes with a width of at least 300 mm and a height of 600 mm greater than the diameter of the pipeline.
Subsequent test work takes place within a day and includes the complete filling of the structure with water with the blocking of the pipeline by temporary plugs. If leaks are not detected, the well walls are backfilled, a blind area measuring 1.5 m is equipped, the joints are insulated with a hot bituminous mixture - work on SNiP has been completed, the system can be put into operation.
The installation schemes for brick structures practically repeat the concrete ones, but instead of combining the rings, a stone is laid out. Waterproofing works are completely identical. Thus, stone wells of any type of sewerage are installed: household, industrial, storm water or drainage. But each design has its own nuances:
- The storm drain is equipped with lattice hatches that have a catchment function;
- Drainage wells themselves are drainage systems, so installation does not require special calculations.
Differences in configuration are determined by the series:
- KFK/KDK - household drains;
- KLV / KLK - storm water;
- KDV / KDN - drainage wells.
The size table gives a complete picture:
Drop wells
A more complex configuration determines the scope and requirements of SNiP for overflow wells. In addition to the tray device, it is necessary to make:
- Installation of risers;
- Have a water pumping equipment;
- Install a water wall;
- Create a practical profile;
- Set up a pit.
Otherwise, with regard to the installation of the shaft, base, floors - the rules are the same as the previous ones.
Important! The exception is a standing overflow well - a metal pipe is required to be installed in the base, which will prevent the destruction of the concrete structure.
The schema looks like this:
- Pipe-riser;
- Pillow water-breaking;
- Metal base (plate);
- Funnel reception (stand-up).
The funnel is required for compensatory discharge processes that are formed in the riser due to the rapid movement of flows. Do-it-yourself creation of overflow wells in private areas is not recommended, unless it is a pipeline with a diameter of 60 cm and a level difference of up to 3 m, but such pipes are practically not used in individual systems, successfully replaced by other types of wells.
The requirements of SNiP for drop wells are simple, installation is recommended in the following cases:
- It is necessary to significantly reduce the depth of the pipeline;
- If there are intersections with other underground utilities;
- Need to adjust the flow rate of wastewater;
- In the case when the well is the last before the direct discharge of wastewater into the river, lake.
The same reasons can serve as a reasonable justification for installing a drop well on your own site.
Arrangement of pipeline inlets into the well
Depending on the conditions of a particular place and soil, the entrance parts to the well are performed in different ways. Installation on dry ground is easier, as it regulates only two types of materials: cement and asbestos-cement mixture. For wet ground installation requires resin strand and waterproofing materials. But both methods are designed only for soils without subsidence.
On moving soils, SNiP installed movable connections: winding pipes with flexible plastic insulating packing. If you deviate from the rules, then you can insert a metal sleeve into the hole of the hatch and arrange a packing from a waterproofing material already inside.
polymer wells
Being a fairly new alternative replacement for stone wells, plastic structures are successfully used to create structures, however, so far only in private households.
Installation is regulated not according to SNiP, but only in accordance with the specifications, so the installation does not require functional features. An important difference between the simplest wells of intra-yard networks is simplicity, a large volume of water passage and the strength of the material. In addition to other advantages, polymer structures can reduce the size, for example, a concrete well of 1 m can be replaced with a plastic one with a diameter of only 30 cm. Despite the small volumes, maintenance will be even much easier than a stone well.
There are plenty of other benefits too:
- Easy installation;
- Low costs for digging pits, pits - smaller sizes do not require large excavations;
- The outlets and tray design are clearly defined by the standards, are factory cast, and therefore there is no need for additional equipment or fabrication;
- The materials for the manufacture of wells are indicated above, polymer structures are combined with any pipes made of plastic, cement, asbestos.
That is why it is worth once again paying attention to the choice before starting the installation of a sewer manhole. All installation schemes are simple, SNiP clearly indicates installation requirements, tray sizes, recommended volumes. But at the same time, the owner will be able to save on related work, the purchase of equipment and time costs.
Summer cottages, where it is not necessary to equip many wells, to build a tray for each, it is more practical to equip them with polymer structures. Modest in size, they do not lose their functionality and practicality.
An integral part of any drainage system are sewer wells, or chambers.
Their device is provided even at the entrance to the septic tank, located at their summer cottage. Therefore, no wonder - every day we see them under our feet. But does everyone know what is inside, and what are these structures for?
This article will tell you everything, or almost everything, about wells, both for those who have no idea about them, and for those who think they know a lot about them.
The equipment of any special facilities for control, repair, maintenance or functional needs is provided for by the requirements of SNiP 2.04.03-85 “Sewerage. External networks and facilities”, and is dictated by common sense.
Let's say there is a drainage pipe in which a blockage has occurred.
What can be done in the absence of a camera that allows you to identify the problem area and eliminate the trouble? The question is rhetorical.
Therefore, the standards describe in sufficient detail where, in what quantities, and which wells to install.
Part 1. Classification of wells
Each structure of this kind has its purpose and method. They can be classified according to several criteria.
There are the following types of sewer wells:
- On the network - wells can be arranged on any drainage networks:
- Domestic and industrial drains
- Drainage
- Stormwater
- According to the material of manufacture:
- Concrete
- brick
- Polymer
- By appointment:
- Variable
- Lookouts:
- With change of flow direction:
- Swivel
- nodal
- Straight-through:
- Linear
- Control
- Flushing
Naturally, the most important characteristic is what functions the sewer well performs.
A drop well differs from a viewing well in that it is designed to change certain physical characteristics of the water flow.
Inspection chambers are designed to perform certain actions on the pipeline.
1. Manholes - tasks by type
Manholes must be installed under one of the following conditions:
- Changing the diameter or slope of the pipeline
- Change of flow direction
- When attaching side branches
- On straight sections, depending on the diameter of the pipe - after 35-300 m
The well itself is made in the form of a shaft with a chamber inside, where the incoming and outgoing pipelines are connected by a special tray.
Each of the wells of this type has its own purpose. However, in one structure, several tasks can be solved at once.
According to the device, all sewer manholes are of the same type, as a rule, the difference can occur only in the depth of occurrence.
All their parameters are quite strictly standardized.
For structures intended to change the direction of the flow of wastewater (nodal and rotary sewer well), the tray is made of a specific shape.
Its parameters are described by the SNiP mentioned above.
The main essence of the requirements is that the angle of rotation cannot be less than 90 °, and is performed with a smooth rounding, the radius of which is from 1 to 5 diameters of the incoming pipe.
A rotary sewer well is placed in those places where a change in the direction of the pipeline is provided, and nodal - where one or two branches are connected to the network.
The nodal well tray can be designed for no more than three incoming pipes, and one outgoing one.
A once-through well is most often linear, that is, located on long sections of the network without branches and turns.
It has a tray that exactly repeats the direction of movement of drains and is designed to check the condition of pipelines, and, if necessary, clean them.
It can also be installed in places where there is a slight change in the input-output level.
It can also be a direct-flow and control well, which is installed at the points of connection of the house or quarter network to the central highway.
But, since in such places a nodal structure is still needed - it is, as a rule, that combines these functions.
Important information!
As a rule, a direct-flow sewer well is arranged - it is installed in the initial sections of the networks, where the drains have not yet gained sufficient speed, and there is an increased likelihood of blockages.
As a rule, water is supplied here, and sometimes pumps are installed.
2. Types of overflow wells
The next type, differential sewer wells, are designed to change and adjust the flow of wastewater in height, as well as to change the speed of their movement - both up and down.
Therefore, the designs of these devices are very diverse.
Cases when it is necessary to arrange sewer overflow wells:
- If you need to reduce the laying depth for the incoming pipeline
- There is a risk that the stream will become too fast or slow, change speed dramatically
- Highway crosses underground structures
- The well is the last one before the discharge into the reservoir, and has a flooded outlet
Based on the variety of tasks, the internal arrangement of these structures also has many design solutions.
Drop types:
- With practical profile and downstream water jet
- Tubular, may have a different design, but always - based on a vertical pipe
- Equipped with water and drain wall
- Multi-stage, shaft type - dampen the flow rate as it follows the cascade
- Fast currents - short sections of the pipeline with a large slope. Designed to accelerate the flow in areas where it is possible to slow it down.
A separate case is overflow sewer wells equipped with a water seal.
Their specificity is that here a change in the flow level is created in the opposite direction - it does not decrease, but rises.
This is achieved through a special chamber, where effluents are pre-accumulated.
A similar scheme is used in those sections of the network in which it is possible for ingress or production of explosive and flammable substances.
The water valve prevents the fire from spreading back in an emergency.
The installation of a differential well in the form of a fast current can also be used in an individual sewerage system, if there is no certainty that the flow volumes will be sufficient for self-cleaning of the pipeline.
Part 2. Well equipment
Everyone is familiar with the picture: an uncle with a grubby face sticking out of the hatch with a shifted lid, who is repairing something there.
And until now, if you ask any post-Soviet person what a sewage well is made of, in 99% of cases he will answer: "From concrete."
And in most cases it will be right, since until now the bulk of these structures on the main pipelines of drainage systems are made in accordance with SNiP, from reinforced concrete rings, less often - cubes, or assembled from slabs.
Modern polymer systems, in many respects superior to their hard stone predecessors, are just beginning to enter the domestic market.
However, for all its shortcomings, the traditional ring, apparently, will remain a symbol of the sewer well for a long time to come.
1. Well made of reinforced concrete elements
SNiP, which regulates the creation of sewer networks, including wells for them, was written at a time when large structures made of polymers, and even high strength, were not yet thought of.
It was also carried out exclusively by the manual method - from where the uncles appeared in the hatches.
Their task was to push the cleaning wire towards the blockage while the assistants at the top rotated the other end of it.
In order for a person to go down inside and work, the following standards were provided: the minimum size of the well was allowed to be 700 mm.
Round slabs are also produced in the same size - the base and the ceiling with a hole for the hatch (Ø 700 mm).
As a result, a standard reinforced concrete well consists of the following elements:
- Round or rectangular base
- Rings
- Cover with hatch hole
- Manhole cover (cast iron, in recent times - it is polymer)
The round plan form was adopted as it optimally resists the pressure of the surrounding soil.
Since it is impossible to predict the place of use in advance, both rings and base plates are produced absolutely even, only with embedded parts (loops) for installation.
In the lower ring, during installation, it is necessary to punch holes at the entry points of pipelines, and on the slab - to arrange a tray of the appropriate shape from concrete or cement.
This design is used both in manholes of all types, and in differential ones - with a device corresponding to the type of structure.
At the same time, the height of the well is gained due to several rings - standard and additional. Before installing the next ring, you have to remove the mounting loops of the previous one.
In this case, all structural elements, including the base and ceiling, as well as the pipeline inlets, are sealed with cement.
It is clear that the waterproofing of sewer wells arranged in this way leaves much to be desired.
As a result: wastewater pollutes the ground, and groundwater contributes to the overflow of sewers.
2. Polymer wells
A completely different degree of freedom was given to designers of sewer networks by wells made of modern plastics.
The development of technology also had its say: modern mobile complexes can serve hundreds of meters of sewer pipelines without descending a person underground.
This made it possible to significantly reduce the size of products.
Where previously it was necessary to use meter-long, at least 70-centimeter rings, now you can install a compact plastic device up to Ø300 mm.
Polymer products are also distinguished by their low weight and the ability to clearly adjust the size to the needs of a particular highway.
Classification of plastic wells
By access:
- Serviced (with personnel access, f from 1000 mm)
- Without access (served from above, f less than 1000 mm)
According to the material of the mine:
- Smooth single wall
- Smooth double wall
- Corrugated single wall
- Corrugated double wall
- Combined
A telescopic (retractable) design of a sewer well made of a smooth-walled pipe is possible, a corrugated pipe has this property by default.
Basically, polymer wells are made separately - the shaft pipe is completed with the necessary types of neck and tray part, where the corresponding piping is made.
But recently, trayless models have also appeared, in particular, those designed for direct-flow wells.
It should be noted that both inspection and overflow sewer wells are made of plastic, but in the latter case, more complex design solutions are used. Polymer products provide almost 100% waterproofing of the mine.
To control, clean or urgently repair the drainage system, special facilities are needed that allow you to quickly access communications. A manhole for water supply is used for such purposes.
What is a manhole
An inspection or inspection well is a sewage device that allows you to quickly access various parts of the plumbing system. Depending on the type of use and the place of installation, the inspection outlet can be of various shapes and diameters. The main difference of its design from other storage tanks and septic tanks in an increased diameter. Its size allows you to easily get inside an adult.
There are such types of manholes:
- Linear. Its installation is carried out exclusively on flat horizontal sections of the water supply. It is installed in several places, for example, nodes or pipe joints;
- Turning. In places where communications turn, an inspection hole is necessarily organized, since it is these areas that are most susceptible to deformation. Its design is a curved body that can be rotated a certain number of degrees in relation to the pipes;
- Nodal is used in areas where several pipes are connected. This is the largest inspection sewer outlet. It can be equipped with 2, 3 or more water outlets;
- The differential is a rather complex configuration, which takes into account the transition from the high level of the pipe to the low one.
Drainage and sewer manhole can be made of various materials: plastic, polymer, cast iron, steel, reinforced concrete. For example, for non-pressure storm sewers, it is customary to use PVC plastic models, which are often pipes of increased diameter. To protect against deformation, they are placed in metal mesh casings.
Reinforced concrete manhole is the most common option for a private house. Concrete models are known for their affordability and reliability - they can be made by hand, besides, concrete does not deform from earth pressure. But the service life of such a branch is less than 20 years. Under the constant influence of effluents, the material is destroyed. Like concrete, brick can serve as the material for the inspection pit. This model can be used to ground the house.
Cast iron models are used to organize monitoring of the state of sewer outlets of multi-storey buildings. Its installation is almost impossible to carry out independently, moreover, over time, cast iron can become covered with various growths. But at the same time, this type of wells is one of the most durable and reliable.
Design features
The street manhole is the following design:
- Bottom. All inspection outlets must be of closed type;
- Working part. It can be a wide ring, a curved geometric figure, less often a square or a rectangle. Here, if necessary, a specialist is immersed;
- Lid, GOST 3634-99. A plastic or cast iron hatch for a manhole is an essential component. It protects the sewer from external pollution and guarantees the safety of households. It is recommended to supplement it with a lock.
Sometimes structures are equipped with a ladder, which allows you to move freely along the well. It is sometimes replaced with shelves. Their drawing is shown below.
The principle of the system is simple. The main pipe passes into the observation structure by connecting to the tank. The junction is carefully sealed. In any inspection outlet there is a tray part - the one in which the inspection is carried out, and the working one. Drains from the sewer pass through the working area, so it has a slight slope.
Video: manhole d 300mm from a plastic pipe
Installation
Installation of a manhole requires compliance with the requirements of SNiP. They say that the tray must be located on a dense sand cushion. Depending on the level of soil freezing, wall insulation may be needed. For these purposes, the pit is equipped with a clay or textile casing.
General requirements for the design and installation of wells:
- They should be located at a distance of at least 30 meters from each other. This indicator depends on the diameter of the main pipeline. For example, a scheme with a pipe from 600 mm requires a minimum distance between the branches of 100 meters. In addition, observation structures should be located at each "important" section of the sewer system;
- If a plastic branch is selected, it is recommended to use a cable type of pipeline. It differs from the classic corrugated surface, equipped with numerous stiffeners;
- It is also important for the drainage system that the inspection structure is not washed away by groundwater.
Step by step installation instructions:
You can buy ready-made manholes in any plumbing stores, their price depends on the brand and design features. For example, a model from Uponor (300 mm) in St. Petersburg will cost 60 euros, and in Krasnodar - 58.
Sewer wells are an inseparable component of the drainage system. They are designed to collect wastewater, distribute the interchange of the main to the discharge zones and clean up certain sections of the pipeline.
Types of sewer wells
A structure of this kind has its own purpose and method of construction. Sewer tanks differ in a number of ways.
By functional purpose
There are several types of wells:
- Cumulative. This is a more modern and environmentally friendly version of the waste pit. It carries out fractionation of effluents and sewage. Liquid and light particles are sent to the filter, and heavy particles sink to the bottom of the storage tank. The volume of the structure is 2-50 thousand liters and depends on the amount of water used. It must be installed at the lowest point of the site, which ensures the correct angle of inclination of the sewer pipes.
- Filtering. The facility is designed to discharge wastewater into the soil. There is no bottom in the design of the well. The installation of filter collectors is allowed only on sandy and sandy-clay soils. As a rule, wells are made from. Sand, crushed stone and special materials can serve as a filter.
- Lookout. It is used for periodic inspection and convenient cleaning of the drainage system in small areas where the direction, slope or diameter of pipes changes, in connection areas. Unlike other types of treatment facilities, presented in the form of a pipe or a collection tank, the inspection tank is an open container. It is mounted in a straight line with a step of 15 meters, while the initial well is placed at a distance from the house no closer than 3 meters and no further than 12 meters.
- Turning. The structure is intended for areas with an extensive drainage pipeline, as well as in cases where the angle of rotation on the pipeline exceeds 90 degrees. This is due to the lack of the possibility of constructing a continuous straight section from a residential building to a storage septic tank. Rotary collectors must be erected at each bend of the laid pipe. This design can be used as a viewing septic tank, which makes it quite easy to clean a certain section of the pipeline through it.
- Variable. Used in areas with a large elevation difference. In this case, the inlet pipe is placed much higher than the outlet. The design of the septic tank has a descent, which is a vertical pipe entering the well, which is connected to the inlet. The descent is attached to the wall of the tank by means of clamps. The length of this element depends on the difference in the section. On the reverse side of the lowering, a 45 degree outlet is installed.
According to the materials used
Collectors are made from various materials:
- Reinforced concrete. The structures are distinguished by their strength, resistance to the negative effects of chemical compounds, and sufficient ease of installation. In addition, they have a large weight and different diameters of the rings. Products are used for the device of septic tanks of the filtering, accumulative and viewing type. Suitable for installation in any type of soil.
- Brick. For the construction of the collector, clay waterproof bricks are often used. Bricks can be used to build square, rectangular or round structures.
- Plastic. Polyethylene structures are characterized by high strength, tightness, wear resistance, as well as ease of installation and relatively low cost. Are applied to the device of rotary, differential and viewing septic tanks.
Reinforced concrete structures are distinguished by their strength, resistance to the negative effects of chemical compounds, and sufficient ease of installation.
Rules and requirements
The process of planning and construction of sewer systems is carried out by Special Rules and Regulations (SNiP), which regulate certain requirements, the main of which are:
- Structures should be located away from drinking water sources and plumbing systems.
- Collectors should be installed at a distance from residential buildings and nearby areas.
- The volume of the tanks must correspond to the number of people living in the house and the average volume of effluents for a certain time period.
- The depth of the pit for the tank should not exceed 2.5 meters, and its diameter should be half a meter larger than the diameter of the structure.
- The need for waterproofing with high groundwater levels.
- The bottom of the pit is mandatory covered with a sand cushion 10 cm high.
- Between the bottom of the tank and the bottom of the pipe a gap of 60 cm must be provided.
Collectors should be installed at a distance from residential buildings and nearby areas
Sewer well device
Preparatory work
Preparation for the construction of sewer septic tanks consists of several stages:
- drawing up a drawing of a sewerage scheme with marking the installation site of the collector, planning on the site;
- cleaning of the construction site;
- organization of a temporary road for equipment at the construction site;
- digging a pit and a trench;
- cleaning and leveling the bottom of the pit.
Stone well device
The construction of a septic tank from reinforced concrete rings is carried out as follows:
Consider the construction technology of a brick collector:
- A pit is being dug, at the bottom of which a formwork is installed and poured with a solution of cement, sand and gravel 20 cm high.
- Allow the solution to dry for 7 days. while periodically spraying with water.
- After the mortar has hardened, laying begins brick walls using a cement mixture.
- The erected walls are plastered sand-cement mortar.
- Waiting for the complete solidification of the solution, perform ironing of the surface by rubbing a thin layer of dry cement into the plaster.
- Collector bottom form depending on its purpose.
- Waterproofing in progress plastered layer.
- Covers interior walls septic tank with mastic or bitumen.
- Form holes for pipes.
- Pipes are started, and the resulting gaps sealed with sealant.
- Fill up the space between the pit and the walls of the well with soil and carefully rammed.
- Cover the collector with a hatch.
The construction of a well made of natural stone is carried out in a similar way. Difficulties in the process of its construction arise due to the unequal size and shape of the stones. Therefore, the arrangement of the collector requires much more time and solution consumption.
Features of the device of wells
When building a septic tank, it is important to take into account the installation features of each, depending on their purpose and material of manufacture.
The peculiarity of the filtering well is that its main task is to clean wastewater from harmful impurities. To accomplish this task, the bottom of the collector is covered with crushed stone about 1 meter high. In this case, the bottom is not completely filled with concrete mortar, but only around the perimeter. This prevents the foundation from collapsing and water from escaping through the center of the circle where drainage and cleaning takes place.
For the construction of a manhole, it is customary to use a pipe with a diameter of 46 cm. This pipe size makes it possible, if necessary, to clean the structure with water through a hose. If it is necessary to descend into the tank, the diameter of the pipe must exceed 92.5 cm.
When erecting a viewing manifold on a site without a pavement, an additional blind area is required, which contributes to the removal of wastewater. If the road surface is of high quality, the installation is carried out 7 cm above the ground surface.
Storage tanks are equipped at the bottom of the site to ensure the flow of water into the well. The structure is placed at a depth of 3-6.5 meters, no more than 7 rings are used during construction. At the bottom, special recesses are made, which are filled with sand or gravel. Water from the tank can be used for domestic needs.
- It is not recommended to make the trench depth too large., because you will need to add soil, which will sag over time. As a result, the highway may change the correct slope.
- To avoid damage to the pipeline under the pipes during their laying no hard objects are allowed.
- Choosing a site for the construction of a filtration or a storage collector, it is necessary to provide for the possibility of the entrance of equipment for cleaning the structure.
- Despite the fact that the sewer septic tank is a wet type of wells, it is required to ensure its tightness. This is necessary in order to minimize the penetration of wastewater into the environment. For waterproofing the joints of the rings, special waterproof compounds are used.
- During the period of providing a waterproofing layer for 3 days, it is necessary to exclude the influence of mechanical loads and low temperatures on the surface. During this time, the areas to be treated should be moistened regularly using a conventional sprayer. You can also cover the surface with a film that helps to reduce the evaporation of moisture.
No sewerage system can function for a long time without constant monitoring and maintenance. For such purposes, special hydraulic structures are used - sewer wells. There are several types of such structures, each of which is designed to solve certain problems. Below we consider the device of sewer wells of the main types, as well as the requirements for their installation in accordance with SNiP.
- differential;
- viewing;
- accumulative;
- filtration.
Worth paying attention. For many people, such devices are mainly associated with city sewers. However, if the autonomous network has a complex structure, then their use becomes relevant for a private house.
differential
In areas with difficult terrain, laying the pipeline can be difficult due to the inability to maintain the correct slope of the main line. If the height of the drop exceeds 30 cm, then it is necessary to use a drop sewer well, the device of which allows you to normalize the speed of the flow of effluents.
The inlet pipe is located at the top, and the outlet at the bottom of the structure. The falling water flow is extinguished against the bottom structure and is directed further along the system. If the drop is too high, additional extinguishing stages can be used to more effectively reduce the wastewater velocity.
The design of the overflow sewer well
Lookout
The longer the line, the more difficult it is to control its operation and carry out repairs. To simplify the maintenance of the system, viewing structures are used, which are installed along the entire length of the pipeline. The interval between them depends on the diameter of the pipe:
- for Ø150 mm - 35 m;
- for Ø200 mm - 50 m;
- for Ø2000 mm - 300 m.
The manhole consists of a rectangular or round shaft, the bottom of which is equipped with a special open-type tray for the flow of wastewater from one pipe to another. An open tray allows you to monitor the movement of wastewater and clean the pipe.
For your information. A variety of viewing structures is a rotary well, which is installed in places where the highway changes its direction. It is at these points that the likelihood of blockages is the highest.
The device of the inspection sewer well depends on the characteristics of the line. It can be mounted on a straight pipe or have one outlet and multiple inlets, making it easy to plan and install the system.
Types of viewing structures for sewerage
Cumulative
The end point of an autonomous sewer is a storage well designed to collect all waste from a drainage, storm or domestic sewer system. The sealed container is gradually filled with water, which is subsequently removed using pumping equipment or a sewage machine.
In case of accumulation of domestic sewage, such a structure is located near the roadway to provide convenience for sewage work. If such a well design is part of a storm sewer or drainage system, then water can be pumped out using a conventional pump and used to water the site.
Sewage storage tank
Filtration
One of the options for removing wastewater from the sewer is to drain water into the ground. To do this, it must undergo additional cleaning using a filtration well. Most often, such an element is installed after a septic tank or is the end point of a drainage and storm system.
Important. The drainage of water into the ground is carried out only at a low level of groundwater. If groundwater is located less than one and a half meters from the bottom of the well, then a storage tank is used.
A typical design of a filtration well for sewage consists of the following elements:
- manhole cover;
- ventilation outlet;
- sewer pipe inlet;
- perforation at the bottom of the tank;
- bottom gravel-sand filter.
Filtration well device
What can a sewer well be made of
Regardless of how the sewer well is arranged and what it consists of, it can be made from different materials. The most popular options are reinforced concrete rings, brick and plastic.
Reinforced concrete rings
The use of reinforced concrete rings is considered a fairly popular method of arranging sewers. The number of elements depends on the depth of the pipeline and the purpose of the structure. For manholes, one ring may be enough, and for storage wells, as a rule, 3 to 5 rings are used.
Installation of the structure is carried out in several stages:
- A pit or trench is being prepared.
- The bottom is leveled, covered with a layer of rubble and poured with concrete.
- Reinforced concrete rings with pre-punched holes for pipes are installed on the frozen base.
- Joints are sealed with bituminous mastic or other waterproofing material.
- A reinforced concrete slab with a hole for the hatch is laid on top.
The installation of a sewer well made of precast concrete requires the use of lifting equipment
Brick
Instead of reinforced concrete rings, you can use a more affordable material - brick. Of course, the masonry process takes longer, but in this case no additional equipment is needed. In addition, you can use old brick for construction, which will save even more.
A brick well can be both rectangular and round in shape. The bottom and top floors are equipped in the same way as when installing concrete rings. Inside the surface is plastered, and outside it is insulated with a hydro-resistant material.
Brick well - an affordable solution for a private house
Plastic
Every day, finished products made of plastic are becoming more and more popular in the arrangement of autonomous sewage systems. Their installation is very fast: the structure is lowered into the prepared trench and joined with the connected pipes.
Interesting to know. Previously, the use of plastic for sewer wells was limited due to the low frost resistance of the material. However, thanks to recent developments, this problem has been solved, and plastic products are now able to withstand temperatures down to -50°C.
Plastic structures are easy to install and maintain
Basic requirements for the construction of wells
According to SNiP, the device of sewer wells must meet the following requirements:
There must be at least one manhole in the area between the outlet of the internal sewer and the entrance to the septic tank. Also, such structures are placed when the system is rotated, in places of branches and when the diameter of the pipeline changes.
The size of the structure depends on the diameter of the pipeline and is regulated as follows:
- with a pipe diameter of up to 17 cm - at least 70 cm;
- from 17 cm to 60 cm - 100 cm;
- from 60 cm to 70 cm - 125 cm;
- from 70 cm to 100 cm - 150 cm;
- from 120 cm and more - 200 cm.
- As a material for manufacturing can be: monolithic concrete, reinforced concrete, brick, rubble stone and polymers (PVC, PP, PE). A combination of these materials is also possible.
- Mines should not be located near sources of drinking water and plumbing systems.
- All joints and entry / exit points of the pipeline must be securely sealed.
Waterproofing the pipe and the outer surface with bitumen
Despite the rather simple arrangement of sewer wells, the installation technology can raise a number of questions from inexperienced craftsmen. By trying to save on professional services, you may end up spending more on system rework and optimization. Therefore, in the absence of relevant knowledge in this area, it is better to turn to specialists.