Sewer wells are part of the system that transports sewage to the place of their cleaning or disposal. They are installed throughout the entire line so that at any time it is possible to repair or replace a section of the pipe.
Current requirements for sewer wells
Basic requirements apply to the locations of sewer wells, their types, sizes. A well should also be equipped on a private plot - this facilitates repair work, which sooner or later will have to be performed.
For the central city sewage system with a pipe width of up to 150 mm, the location of inspection hatches is provided every 35 meters. If the pipes have a diameter of 200 mm, hatches are equipped every 50 m. In addition, wells are placed at each section where the line turns, changes in its level, slope, branching or change in the diameter of pipes. In such places, blockages most often occur, which must be removed mechanically.
Technical conditions and operating instructions are developed separately for each material from which the pipes are made.
The diameter of the inspection hatch depends on the diameter of the line:
- with a width of up to 150 mm, the hatch must be at least 70 mm;
- 600 mm - diameter 1 m;
- 1200 mm - hatch diameter 2 m.
If the pipeline is over 1500 mm, the manhole should be about 3 m. This is necessary for a high-quality repair of the pipeline, where several people usually work at the same time.
Construction requirements include the sequence of actions, the selection of suitable materials, based on the characteristics of the soil, its mobility, depth and climatic conditions.
The main types and device of sewer hatches
- inspection - their diameter does not allow a person to go down inside, all work is carried out using tools from the surface of the earth, a plastic pipe with a diameter of up to 700 mm acts as a well;
- serviced - a person can go down and carry out repairs, the diameter of such hatches is from 1000 mm.
By functionality, they are distinguished:
- Storage well. The volume depends on how many people live in the house. The function is to collect and distribute sewage. To facilitate the transportation of wastewater, the storage tank is installed at a low point in the area to avoid blockages along the path of the wastewater. They are made of plastic, brick, reinforced concrete rings, concrete.
- Filtering. Performs the function of removing the liquid fraction through the open bottom. It is usually installed after the storage tank - settled liquid without solid particles flows into it. The presence of a filter well increases the time intervals between pumping out sewage. The second septic tank may contain bacteria that help break down the organic component of the effluent.
- Lookout. Designed to assess the state of the sewerage system in the city or on your own site. In a large area, it is recommended to install several hatches in those places where the pipe changes diameter, turns, changes the angle of inclination, or before tapping into a centralized system.
- Turning. They are installed in those places where the system branches into several directions or turns.If the sewer is clogged, most likely this will happen in this area.
- The cross-over well of the sewage system is installed in the case when the difficult terrain does not allow to correctly set the angle of inclination of the highway. The differential hatch is distinguished by the presence of a vertical pipe, for which an angle of 45 degrees is set.
Inspection hatches are used for any type of wastewater - domestic, industrial or natural - rain, melted snow. The material of the pipes is chosen so that they can withstand the temperature and chemical composition of the transported fluids.
Well construction - components
- a working chamber of sufficient size so that a person who serves this system can fit in it;
- neck;
- hatch, which is made of concrete or plastic;
- tray;
- base of a concrete slab, laid on a layer of crushed stone.
The working chamber is equipped with iron brackets (steps), along which the workers go down inside. The scheme of the sewer well device depends on the functions of the line. If this is a home system, the diagram will be simplified. If it is industrial, with various ramifications and biases, the circuit will need a more complex and functional one.
Materials for making wells
Previously, the main material for the construction of viewing wells was brick. It was laid out and fastened with cement mortar. Now in some old cities there are still examples of such hatches. The arrangement took time and effort. The tightness of the brickwork deteriorates over time and odor may spread.
Over time, the brick began to be replaced with concrete rings. Such material lasts longer and does not allow liquids and odors to pass through. It is faster to mount it: you need to dig a pit of the right size and use a technique to install the rings. To seal the gap between the components, cement is used.
Polypropylene is the material of the future when arranging inspection wells. Its chemical and physical properties allow it to work at high temperatures of liquids - the material softens at a temperature of +140 degrees. It does not corrode. Polypropylene can be affected by ultraviolet radiation, but since the sewer is installed underground, this does not affect the quality of the pipes.
Polypropylene is the second largest sold in the world. Old sewer lines are gradually being replaced by plastic products.
Polyethylene is a durable, heat-resistant material. It has several varieties. For example, cross-linked or ultra-high molecular weight polyethylene is designed to work in extreme conditions - in severe frosts, with a high coefficient of friction from the inside, under shock loading, for working with especially aggressive liquids that flow from industrial facilities to their storage place.
Fiberglass is another polymer material that has a degree of strength comparable to steel products. At the same time, fiberglass products are lighter, do not corrode, and are able to transport liquids that aggressively affect metal or other types of plastic. The main component is quartz fiber.
Corrugated pipes are often used for the installation of inspection chambers. They have a high degree of strength due to protrusions along the entire circumference, withstand loads in the form of ground movement, if such phenomena are typical for a given area.
Design and installation stages
Before the start of construction work, preliminary activities are carried out:
- determination of the highest and lowest levels of the site;
- marking the territory for digging a foundation pit and pipe trenches;
- transplanting plants that are in the path of the highway;
- cleaning of buildings that interfere with work.
The work begins with digging a pit and arranging the walls. Further:
- the bottom is being prepared - it is poured with bitumen or covered with crushed stone;
- concrete rings or plastic pipes of the required diameter are being installed - depending on whether it is a serviced or inspected well;
- walls and joints of concrete rings are rubbed with bitumen or cement mortar;
- when connecting the inlet and outlet pipes, the joints are also covered with hot bitumen, if the plastic can be melted or welded, this is an easier way to seal the structure.
At the end, a concrete or polymer hatch is installed. For a private house, plastic models are more suitable because of their aesthetic appearance.
Maintenance of manholes
Wells, both urban and private, require regular inspection. Repair or cleaning is necessary if the bottom is heavily silted up and an unpleasant odor is heard from the hatch. After the winter period, there is often a failure in the work of engineering networks.
Usually, for repair work, service specialists are called in, who installed the entire sewer system. Do-it-yourself cleaning of the viewing well can be done with the tools and experience.
In private areas, the accumulation of garbage in the well is unlikely, but in the city this is the biggest problem, especially after heavy rains - well mines are clogged with household waste and plastic.
With the wrong installation of the sewage system, repair work will become an integral part of life, therefore, their construction must be trusted by professionals.
The price of a well for sewerage consists of the cost of the materials themselves, as well as the work on their installation. The most reliable and easy to install are plastic shafts for wells. If desired, you can choose reinforced structures at a more expensive price, or conventional ones for inspecting the condition of the pipes. For a summer residence or a country house, it is recommended to choose polymer materials and plastic hatches so as not to spoil the appearance of the site.
