Construction of inspection wells leading into the house. Construction of a sewer well: requirements and types

The process of planning and construction of sewer systems is not complicated, however, there are special rules and regulations of SNiP that impose certain requirements for installation and materials. There are also special government services that check the design of the sewer well according to SNiP, and if violations are detected, they may impose a fine or require that the system be rebuilt.

Therefore, before building a sewer well with your own hands, you need to familiarize yourself with their main types and installation rules.

Types of sewer wells

According to their functional purpose, mines are divided into several main types:

viewing rooms;
differential;
rotary;
accumulative;
filtration.

Each of these types performs its specific function.

Inspection well

An inspection well (photo) is a shaft that is located above the main drainage line. Such a shaft makes it possible to conduct a visual inspection of the system’s performance and, if necessary, carry out its flushing or mechanical cleaning during operation.

In most cases, such shafts are installed on straight sections of drainage at a certain distance, however, shafts installed at turns or intersections of communications can also be called inspection shafts.

Inspection shafts can be of several types:

linear, installed on straight sections;

rotary, installed in places where the direction of the highway changes. In order to avoid hydraulic resistance, the angle between the incoming and outgoing lines must be at least 90 degrees;

nodal, installed at the junction of several highways. Such chambers connect one outlet pipe with several incoming pipes, but there can be no more than three incoming pipes;

control, installed in places where the private system is connected to the main one.

Note! The distance between inspection shafts is determined by the diameter of the pipe. For example, with a pipe diameter of 15 cm, the distance between the wells is set to no more than 35 meters. With a pipe diameter of 50 - 70 cm, the distance between the shafts is 75 meters.

Drop well

The construction of a differential sewer well is a simple structure (see photo), which is installed in the following cases:

when reducing the depth of the ditch under the drainage main;
when bypassing other underground pipes or communications;
to prevent high fluid velocity.

According to the type of design and functions, drop wells are divided into several types:

a conventional shaft with a liquid supply in the upper part and an outlet in the lower part;
difference with the baffle-drain wall to reduce the flow rate;
short channels with a large degree of slope to increase flow speed;
a mine with multi-stage drops.

Rotary well

Such shafts are installed in those sections of the highway where sharp turns of the channel are necessary, since it is in these places that blockages of the system most often occur.

Storage well

Storage shafts or wells (photo) are designed for collecting and storing waste liquid with its subsequent pumping using a pump or special vacuum trucks.

For private homes, installing sewer wells of this type can be an advantageous solution if the nearest central system is far away or non-existent. Depending on the volume, such shafts can be made of reinforced concrete rings, monolithic concrete or large plastic containers.

With a small amount of wastewater, installing a plastic tank is most justified, since the price of such a tank is low and the installation process can be done with your own hands, without the involvement of equipment or professional construction teams.

Filtration well

Filtration shafts or wells can be open or closed. Both types of wells are designed to separate wastewater and separate large debris and heavy substances from the liquid.

Open-type structures are mines made of perforated concrete blocks, where liquid goes through special holes into the ground, and heavy substances remain within the mine and are subsequently removed by special equipment for burial or disposal.

Closed wells are sealed containers with technological outlets, which are located at different heights. As wastewater enters, floating particles are removed by the upper channels, sedimentary layers are removed by the lower ones.

Sewage is an indispensable thing in city life, used to drain wastewater, which in its absence would have no place to go. It is present in every residential area.

What does a sewer well consist of? – a question of interest to many. The structure of the sewer well is as follows:

Bottom – the lower part of the well, which comes into direct contact with wastewater.
The shaft is a 1.8 m long cavity inside a well equipped with a ladder, used for various technical work.
The working chamber is the space in which all work with pipes is carried out.
Neck - the upper part of the well with a hole for the hatch.
The hatch is the closing component of the well, which allows you to avoid foreign objects, including animals and people, from entering the well.

In graphical expression, the design of a sewer well has the following form:

The designs of sewer wells are quite varied, so they can be divided into the following types.

Variable

Differential sewer wells are structures installed in places where it is necessary to reduce or increase the intensity of wastewater.

Installed in the following cases:

When there is a risk of changing the flow rate.
When a sewer crosses a highway.
When laying another pipeline.
In case of partial flooding, the water outlet.

Observation

Inspection sewer wells - wells used to monitor the condition of the system as a whole, as well as to eliminate faults that have arisen in it, have no analogues.

Installed in the following places:

In the area where the slope and diameter of the pipe changes, it is most prone to failure.
In the area of flow change.
In places where the main pipeline branches off.
In places that seem to be reliable, but still require surveillance.

Rotary

Mounted in places where the pipeline turns.

Nodal

Installed in case of branches from the main pipeline.

Direct flow

Linear – designed directly for routine checking and cleaning of networks.
Flushing - installed directly at the beginning of the network to flush it.
Control - installed in places where treated water is directly discharged into the sewer system to monitor its quality indicators.

Features of calculating the size of a sewer well and the depth of its installation

The first thing you need to do before building a well is to calculate its volume and determine its location. When making calculations, you should, first of all, take into account the number of bathrooms and people in this house. The volume of the well is directly dependent on the amount of water consumed. Thus, a family of four uses 1000 liters of water per day.

According to existing standards, it is considered that a well for drainage, with a bottom area of 1 sq. m. m. copes with a volume of water equal to one cubic meter. The working volume of the pit must have a reserve equal to three times the daily norm. Accordingly, the volume of the pit for a family of 4 people should be 3 square meters. m.

Knowing approximately the required volume of the sewer, you can calculate its size. The average depth of a sewer well is 2.5 – 3 meters. We subtract the distance above the drain pipe, which is equal to 70 cm, and obtain the working depth of the well, the maximum of which is 2.3 meters. Next, using a simple mathematical operation of a geometric nature, we calculate its volume.

The volume of a sewer well is calculated using data such as:

The area of the well bottom.
Well height.

The most common wells are round in shape, this is explained by their simplicity and ease of maintenance.

Types of bottom

Round bottom - such wells are often called barrels.
Quadrangular bottom - made in the shape of a square or rectangle.

The area of a circle is calculated using the following formula - S = πR2. Based on this, it turns out that the volume for a well with a working pit volume of 3 square meters. m will be equal to 3 m 3 = 2.3 m * 3.14 * R2.

Having made some calculations, we find the value of R, it is equal to 0.65 m, and accordingly a hole with a depth of 3 meters should have a diameter of 1.3 meters. In the case of a rectangular or square well 3m deep. its bottom area is 2.3 m.

The depth of the sewer well is calculated taking into account the additional depth, width and height, which will later be used for reinforcing walls that protect the well from the crumbling earth ball. Installation of protective walls can be made of the following material:

Reinforced concrete rings.
Concrete.
Brick.

The bottom of the pit is covered with layers of sand and crushed stone, the thickness of which is at least 30-40 cm. Taking into account the brickwork, which is 12 cm, the width of the pit should be increased by 25 cm, and the depth by 40 cm - a layer of crushed stone and sand. When making calculations, rounding up is possible; rounding down is unacceptable. It should be remembered that the depth of the sewer well is one of the most important indicators, the calculations of which require special attention.

Features of the design and installation of sewer wells made of concrete rings

Concrete rings are widely used among utility companies involved in the maintenance and installation of underground pipelines. They are also used for the construction of drainage and storm sewer systems, underground pipelines, and collectors. They have no analogues.

High-level performance properties make it possible to use it in any climatic region. Due to the huge number of advantages, concrete sewer wells are in great demand.

Concrete rings for wells have a number of advantages, such as:

Low cost.
Speed of installation work.
Ease of waterproofing work.
High structural strength.
Long service life.
Correct geometric shape.
Tight fit of the rings to each other, ease of eliminating remaining gaps.

Disadvantages of concrete rings:

Low threshold for resistance to splitting, increased fragility and cracking.
The need for vehicles to move even a short distance.
Huge mass, requiring high costs for installation and delivery.

Reinforced concrete rings are a common material widely used in laying sewer systems. Construction of a sewer well using concrete rings requires the following steps:

Development of a scheme for further installation and calculation of the cost of work.
Preparing a pit, which includes digging a hole according to predetermined dimensions.
Having created a pit, they begin to work on the bottom of the well.
We install the main (first) ring, which sits on the concrete solution. After this, the pipes are laid into the holes made in advance in the rings. The remaining cracks at the joint are tightly sealed with a sealing agent.
Next, all other rings are installed in such a way that the position of their locks coincides. The resulting cracks are sealed with sealant.
A concrete slab and hatch are placed on top of the resulting structure.

Features of the design and installation of brick sewer wells

The construction of a brick sewer well requires a number of knowledge and skills. Knowledge is required to allow the work to be carried out, starting with the installation of the frame and other structures and ending with the internal and external design of the structure.

To build a brick well, only red - burnt brick or stone of natural origin is used. To connect the materials together, a cement solution made from river sand is used. Also, components such as brackets, anchors, round frames and fittings are used for a brick well.

Installation of a brick sewer well has the following sequence:

Having previously calculated the volume of the well and its dimensions, we mark the pit. A small pit can be dug manually or using an excavator.
At the bottom of the resulting pit we install the formwork and fill it with a 20 cm layer of mortar made from sand, crushed stone and cement. Leave to harden for 1 week, periodically moistening with water.
After the mortar has hardened, we begin laying the walls using cement mortar.
We plaster the resulting (finished) walls with cement mortar. After it has set, we perform ironing - rubbing dry cement into the wet plaster.
The bottom of the well is formed depending on its further purpose.
We waterproof the dried plaster. We take mastic or hot bitumen and cover the entire inner surface of the well.
We knock out a hole for the pipes. We insert the pipes and seal the remaining gap with silicone.
We fill the gap formed between the pit and the walls of the well and cover it. For a drainage well, ventilation is installed, which is done by installing a plastic pipe. A fungus is placed on top of the pipe. The edges of the well are covered with soil so that the base of the well is 10 cm above ground level.

Plastering a well

The solution used for plastering should have the thickness of purchased sour cream. The solution is applied with movements directed from top to bottom. To obtain smooth walls, vertical and horizontal beacons are used. Existing metal structures are also covered with a layer of plaster, which will protect them from corrosion. Next, they design the head and clean the bottom, which is covered with a gravel-sand mixture.

The construction of a well from natural stone is carried out according to the same scheme, only it is much more complicated, due to the fact that the stones have unequal sizes and shapes, which require time to adjust them and greater consumption of mortar, which costs money.

The sewer system consists of many elements that together ensure the coordinated operation of the network as a whole. The inspection well is in this case the main structure, which not only checks the functioning, but also timely cleans the sewer. Thus, we can say that inspection wells are the central link of the external sewerage system.

linear, installed on straight sections of the entire sewer system at a distance that depends on the diameter of the pipes;
rotary wells are located in places where the direction of the line changes, i.e. on turns. This type of well differs from the linear one in the configuration of the tray, which has the shape of a smooth curve with the smallest radius of curvature, which is equal to three pipe diameters. The rotation angle should not exceed 90 degrees.
junctions are installed at the connection points of several sewer lines. They have a tray assembly connecting no more than one outlet and three inlet pipes. Nodal wells in large collector networks are called connecting chambers;

Types and types of inspection wells depending on the internal structure of the pipeline

control tests are carried out in parts of the connection of the factory, intra-block or yard network to the street network, and they are located outside the boundaries of the red line of the construction site - from the side of the houses. Control wells are necessary to control the operation of the sewer system of added objects;
flushing wells are needed for flushing the system in the primary (starting) areas, where precipitation is possible due to low velocities;
drop wells are provided in areas where the elevation of the outlet and inlet pipe trays differs;
special wells with enlarged neck and hatch dimensions are mounted on collectors 600 mm in diameter at a distance of more than 50 m from each other.

How is a water supply inspection well constructed?

Regardless of the type of accessory, the inspection drainage well consists of a base, a tray, a working chamber, a neck and a hatch.

Wells can be made of different materials: brick, reinforced concrete blocks, rubble stone.

In the diagram (plan), inspection wells come in round, rectangular and polygonal shapes. The base consists of a reinforced concrete slab, which is laid on crushed stone. The main technological part is the tray, which is made of monolithic concrete (M 200) using templates - formwork, followed by rubbing the surface with iron or cement.

The pipeline passes into the tray part through which wastewater flows. In linear wells, the tray part is straight, and the surface in the lower part is vertical. The height of the tray is not less than the diameter of the larger pipe. Berms (shelves) are formed on both sides of the tray, which must be given a slope of 0.02 towards the tray side. The shelves serve as platforms on which workers are located during operational activities.

Important!
The working chamber should have the following dimensions: height 1800 mm, and the diameter depends on the diameter of the pipes. So with d 600 mm - 1000 mm; at d 800-1000 mm - 1500 mm; at d 1200 - 2000 mm.

The well necks are standard - 700 mm. With a pipe diameter of 600 mm, the necks must be installed so that they allow the entry of cleaning devices (cylinders and balls).
Necks and working chambers are equipped with hanging ladders or brackets for descent.

The transition to the neck is possible using a conical part or a reinforced concrete floor block.
At ground level, the necks end in a hatch, which can be light or heavy.

Important!
The installation of hatches with an improved road surface is carried out 70 mm from the earth's surface - in the green zone; in undeveloped areas - 200 mm above the ground.

If the well is located on an uncovered area, then a blind area should be built around the hatch to drain the water.

Standards for the manufacture of hatches

At first glance, it may seem that the hatch is not such an important element of the manhole, but in fact this is not the case. The proof is the standards that must be observed during their manufacture. The main material is cast iron (GOST 3634-61). Cast iron hatches consist of a body with one cover for installation on necks with a diameter of 700 mm and with an opening for passage with a diameter of 620 mm. Heavy hatches are laid on the roadway and have a mass of 134 kg, while light hatches, laid mainly on sidewalks, weigh no more than 80 kg.

Along with cast iron, polymer materials are used for manufacturing, which are characterized by strength, lightness, durability and environmental safety.

This is interesting!
During manufacturing, special fillers are added to polymer hatches, which make the recycling process impossible. That is why such hatches are of no interest to waste collectors.

Intervals between inspection hatches

When installing, it should be taken into account that the distance between linear type inspection wells depends on the diameter of the pipe. It looks like this:
d = 150 mm - 35 meters;
d = 200 mm - 50 meters;
d = 500 mm - 75 meters;
d = 700-900 mm - 100 meters;
d = 1000-1400 mm - 150 meters;
d = 1500-2000 mm - 200 meters;
d > 2000 - 300 meters.

The distance between adjacent inspection wells is strictly standardized

Inspection wells are the main component of the sewer system, not only providing unhindered inspection and monitoring of the operation of city pipelines, but also creating conditions for carrying out important operational activities. It is noted that the process of constructing inspection wells is a costly undertaking, because it requires, in addition to time and effort, the use of large-block massive structures and specialized equipment.

Installation procedure for inspection wells

We determine the location of the inspection well and prepare it for excavation work - we clear the area, think through the access of equipment, if necessary.
We prepare the foundation pit according to pre-made calculations.
We arrange waterproofing. To do this, pour gravel and crushed stone onto the bottom of the dug pit, and pour a layer of bitumen on top.
For a reinforced concrete inspection well, the bottom is filled with concrete (the tray is made using reinforcement). When the concrete dries (it will take about two weeks), you can install the rings.
We seal the joints and gaps.
The connection between the pipes and the inspection well is isolated. Bitumen or concrete mortar is suitable for this.
We test the well - temporarily fill it with water and leave it for at least a day.
We fill the outside of the well with soil, compacting the soil tightly.
For the neck we make a concrete blind area about 1.5 m wide.

Video: installing a plastic manhole

Video: manhole made of plastic pipe

Video: advantages of plastic wells

The video clip will introduce you to the advantages of progressive plastic manholes:

Sewage wells are an inseparable component of the drainage system. They are designed to collect wastewater, distribute pipeline junctions among discharge zones, and clean certain sections of the pipeline.

Types of sewer wells

A structure of this kind has its own purpose and method of construction. Sewage 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 option for a waste pit. It carries out fractionation of wastewater and sewage. Liquid and light particles are directed to the filter, and heavy particles fall 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 structure is designed to discharge wastewater into the soil. The well design has no bottom. The installation of filter collectors is allowed only on sandy and sandy-clayey soils. As a rule, wells are made from. Sand, crushed stone and special materials can serve as a filter.
Lookout. 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 collection tank, the inspection tank is an open container. It is mounted in a straight line in increments 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 a branched 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 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 an inspection septic tank, which makes it quite easy to clean a certain section of the pipeline through it.
Perepadny. Used in areas with large elevation differences. In this case, the inlet pipe is placed much higher than the outlet pipe. The design of the septic tank has a drop, which is a vertical pipe going into the well, which is connected to the inlet. The lowering is attached to the tank wall using clamps. The length of this element depends on the difference in the area. On the reverse side of the lowering, a 45 degree bend is installed.

By materials used

Collectors are made from various materials:

Reinforced concrete. The structures are durable, resistant to the negative effects of chemical compounds, and fairly easy to install. In addition, they have a large weight and different ring diameters. The products are used for constructing septic tanks of filtering, storage and inspection types. Suitable for installation in any type of soil.
Brick. For the construction of the collector, clay waterproof bricks are often used. Brick can be used to build structures of square, rectangular or round shape.
Plastic. Structures made of polyethylene are characterized by high strength, tightness, wear resistance, as well as ease of installation and relatively low cost. They are used for installing rotary, differential and inspection septic tanks.

Reinforced concrete structures are durable, resistant to the negative effects of chemical compounds, and fairly easy to install

Rules and requirements

The process of planning and construction of sewer systems is carried out by Special Rules and Regulations (SNiP), regulating certain requirements, the main of which are:

Structures should be located away from from drinking water sources and plumbing systems.
Collectors should be installed at a distance from residential buildings and nearby areas.
The volumes of the tanks must correspond to the number of people living in the house and the average volume of wastewater 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 at 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 It is necessary to provide a gap of 60 cm.

Collectors should be installed at a distance from residential buildings and nearby areas

Construction of a sewer well

Preparatory work

Preparation for the construction of sewer septic tanks consists of several stages:

drawing up a drawing of a sewerage diagram with marking of the installation location of the collector, layout of the site;
cleaning the construction site;
organization of a temporary road for equipment at the construction site;
digging a pit and trench;
cleaning and leveling the bottom of the pit.

Construction of a stone well

The construction of a septic tank from reinforced concrete rings is carried out as follows:

Let's consider the technology of building a brick collector:

A pit is being dug, at the bottom of which formwork is installed. and filled with a mortar of cement, sand and crushed stone 20 cm high.
Allow the solution to harden for 7 days, while periodically sprinkling with water.
After the mortar has hardened, start laying brick walls using cement mixture.
The erected walls are plastered sand-cement mortar.
Without waiting for the solution to completely harden, iron the surface by rubbing a thin layer of dry cement into the plaster.
The collector bottom is formed depending on its purpose.
Waterproofing in progress plastered layer.
Cover the inner walls septic tank with mastic or bitumen.
Form holes for pipes.
The pipes are started, and the resulting gaps sealed with sealant.
Filling the space between the pit and the walls of the well with soil and compacted thoroughly.
Cover the collector with a hatch.

The construction of a well from natural stone is carried out according to a similar scheme. Difficulties in the process of its construction arise due to the unequal size and shape of the stones. Therefore, the construction of the collector requires much more time and solution consumption.

Features of well construction

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 a filter 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 solution, but only along the perimeter. This prevents the destruction of the base and the release of water through the center of the circle in which drainage and cleaning occur.

To build an inspection well, 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 using a hose. If you need to go down into the tank, the diameter of the pipe must exceed 92.5 cm.

When constructing an inspection collector on an area without a road surface, an additional blind area is required, which facilitates the drainage of wastewater. If the road surface is of high quality, installation is carried out 7 cm above the ground surface.

Storage tanks are installed in the lowlands of the site to ensure water flows 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 depressions are made, which are filled with sand or crushed stone. Water from the reservoir 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 subside over time. As a result, the highway may change the correct slope.
To avoid damage to the pipeline under the pipes during their installation It is forbidden to place hard objects.
Choosing a site for the construction of a filtration or storage manifold, it is necessary to provide for the possibility of equipment access to clean the structure.
Despite the fact that a sewer septic tank is a wet type of well, its tightness must be ensured. This is necessary in order to minimize the penetration of wastewater into the environment. To waterproof the ring joint areas, special waterproof compounds are used.
During the period of providing a waterproofing layer for 3 days, it is necessary to exclude the impact of mechanical loads and low temperatures on the surface. During this time, the treated areas should be regularly moistened using a regular sprayer. You can also cover the surface with a film, which helps reduce moisture evaporation.

An integral part of any drainage system are sewer wells, or chambers.

Their installation is even provided at the entrance to a septic tank located on a summer cottage. Therefore, it is no wonder that every day we see them under our feet. But does everyone know what’s inside and what these structures are intended 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 structures for control, repair, maintenance or functional needs is provided for by the requirements of SNiP 2.04.03-85 “Sewerage. External networks and structures,” and is dictated by common sense.

Let's say there is a drainage pipeline in which there is a blockage.

What can be done in the absence of a camera that can identify the problem area and eliminate the problem? The question is rhetorical.

Therefore, the standards describe in sufficient detail where, in what quantities, and what kind of wells to install.

Part 1. Classification of wells

Each structure of this kind has its own purpose and method. They can be classified according to several criteria.

The following types of sewer wells are distinguished:

By network - wells can be installed on any drainage networks:
- Domestic and industrial wastewater
- Drainage
- Stormwater
According to the material of manufacture:
- Concrete
- Brick
- Polymer
By purpose:
- Variable
- Observations:
- With a change in flow direction:
  - Rotary
  - Nodal
- Straight-through:
  - Linear
  - Tests
  - Flushing

Naturally, the most important characteristic is what functions the sewer well performs.

A differential well differs from a viewing well in that it is designed to change certain physical characteristics of the water flow.

Inspection cameras are designed to perform certain actions on the pipeline.

1. Manholes - tasks by type

Manholes must be installed if one of the following conditions is met:

Changing the diameter or slope of the pipeline
Changing 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, one structure can provide solutions to several problems at once.

In terms of design, all sewer inspection wells are of the same type; as a rule, the difference can only arise in the depth of their location.

All their parameters are quite strictly standardized.

For structures designed to change the direction of wastewater flow (nodal and rotary sewer manholes), the tray is made of a specific shape.

Its parameters are described by the above-mentioned SNiP.

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 junction wells are placed 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 pipe.

A direct-flow well is most often linear, that is, located on long sections of the network without branches or turns.

It has a tray that exactly follows the direction of movement of the 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.

There can also be a direct-flow control well, which is installed at the points where a house or block network is connected to the central highway.

But, since in such places a central structure is still needed, it is this that, as a rule, combines these functions.

Important information!

As a rule, a direct-flow sewer well is installed - 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 differential wells

The next type, differential sewer wells, are designed to change and regulate the flow of wastewater in height, as well as 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 install sewer drop-off wells:

If you need to reduce the laying depth for the incoming pipeline
There is a risk that the flow will become too fast or slow, changing speed dramatically
The highway crosses underground structures
The well is the last one before discharge into the reservoir, and has a flooded outlet

Based on the variety of tasks, the internal structure of these structures also has many design solutions.

Types of drops:

With a practical profile and a water outlet in the lower pool
Tubular, can have a different design, but always based on a vertical pipe
Equipped with a water trench and drain wall
Multistage, shaft type - dampen the flow velocity as it moves along the cascade
High-flow pipelines are short sections of pipeline with a large slope. Designed to accelerate the flow in areas where it can slow down.

A separate case is differential 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 wastewater is pre-accumulated.

A similar scheme is used in those sections of the network into which explosive and fire hazardous substances may enter or be produced.

The water valve prevents the fire from spreading back in an emergency.

The installation of a differential well in the form of a high-flow can also be used in individual sewers, if there is no confidence that the volume of drainage will be sufficient for self-cleaning of the pipeline.

Part 2. Equipment of wells

Everyone is familiar with the picture: a guy with a grimy face sticking out of a hatch with a shifted lid, fixing something there.

And to this day, if you ask any post-Soviet person what a sewer well is made of, in 99% of cases he will answer: “Concrete.”

And in most cases he 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, superior to their hard-stone predecessors in many respects, are just beginning to enter the domestic market.

However, with all its shortcomings, the traditional ring will apparently remain a symbol of the sewer well for a long time.

1. Well made of reinforced concrete elements

SNiP, which regulates the creation of sewer networks, including wells on them, was written at a time when large structures made of polymers, and even high strength ones, were not even thought of.

It was also carried out exclusively by hand - which is where the guys appeared in the hatches.

Their task was to push the clearing wire towards the blockage, while assistants above rotated its other end.

In order for a person to get 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 - base and ceiling with a hole for a hatch (diameter 700 mm).

As a result, a standard reinforced concrete well consists of the following elements:

Round or rectangular base
Rings
Ceiling with a hole for a hatch
Manhole cover (cast iron, recently sometimes polymer)

The circular plan shape was adopted as it optimally resists the pressure of the surrounding soil.

Since it is impossible to predict in advance the place of use, both rings and base plates are produced absolutely flat, only with embedded parts (hinges) for installation.

During installation, you have to punch holes in the lower ring where the pipelines enter, and on the slab you have to make a tray of the appropriate shape from concrete or cement.

This design is used in manholes of all types, and in differential wells - with the installation of structures corresponding to the type.

The height of the well is gained through 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 pipeline inlets, are sealed with cement.

It is clear that the waterproofing of sewer wells constructed in this way leaves much to be desired.

The result: wastewater pollutes the ground, and groundwater contributes to sewer overflow.

2. Polymer wells

Wells made of modern plastics gave sewer network designers a completely different degree of freedom.

The development of technology has also had its say: modern mobile systems can service hundreds of meters of sewer pipelines without going underground.

Thanks to this, it became 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 diameter 300 mm.

Polymer products are also distinguished by their low weight and the ability to accurately adjust the size to the needs of a specific highway.

Classification of plastic wells

By access:

Serviced (with personnel access, f from 1000 mm)
Without access (served from above, diameter less than 1000 mm)

According to the mine material:

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 manufactured separately - the shaft pipe is equipped with the necessary types of neck and tray part, where the corresponding piping is installed.

But recently, trayless models have also appeared, in particular, designed for direct-flow wells.

It should be noted that both inspection and differential sewer wells are made from plastic, but in the latter case more complex design solutions are used. Polymer products provide almost 100% waterproofing of the mine.