The sewerage system has many elements that are designed to ensure the smooth operation of the network. The viewing well acts as one of the main structures, with the help of which specialists carry out a functional check and clean the sewer. This indicates that these components of the system are the central link in the external sewage system.
Main varieties
Depending on the purpose, some types of manholes can be distinguished, among them: linear, rotary, nodal, control, flushing, differential, as well as special ones with enlarged neck sizes. Linear should be located on the straight sections of the sewer system in increments that depend on the diameter of the pipe. Swivels are located in those places where the system changes the direction of the lines, for example in turns. This kind of wells differs from the above-described configurations of the tray, which is represented by a shape in the form of a smooth curve with a minimum radius of curvature. It should be equal to three pipe diameters. When determining the angle of rotation, specialists should remember that it should not be more than 90 °. The nodal manhole is located at those points where several lines of the system are connected into a single unit. They have a chute assembly that connects a maximum of three inlet and outlet pipes. If we are talking about large collectors, then the nodal wells in them are called connecting chambers.
Description of other types of manholes
Control wells are located at the points of connection of the yard, intra-channel or factory network to the one located on the street. They are installed outside the construction line from the side of the houses. Such wells are necessary to control the operation of the system of added objects. Flushing wells are installed in the starting areas, where there is a chance of precipitation due to low speeds. The overflow wells should be located at the points where the inlet pipe and the mark of the outlet pipe tray differ. Special wells have a more impressive neck and hatch. The collector should have a diameter of 600 mm, and the distance between the wells will be 50 m or more.
Features of the manhole
The viewing well is based on a tray, a hatch, a neck and a working chamber. The design can be made of different materials: rubble stone, reinforced concrete blocks or bricks. In the diagram, these elements are indicated by polygonal, round or rectangular shapes. The base has a reinforced concrete slab laid on a pillow of crushed stone. The main technological part is the tray made of monolithic concrete brand M200. In this case, formwork is used, which is poured with cement mortar and reinforced with reinforcement.
The viewing well has a pipeline that goes into the tray part, and wastewater moves along it. If we are talking about a linear variety of the well, then its chute part is straight, and the bottom is vertical. The height of the tray should not be less than the parameter that determines the diameter of the larger pipe. On both sides of the tray there should be shelves that have a slope in its direction. These regiments will serve as the sites on which workers are housed during repair work.
Features of the main components of the well
If you are interested in the device of the inspection well, then you should know that its working chamber has a height of 1800 mm. Whereas the diameter will be determined by the diameter of the pipe. If the last parameter is 600 mm, then the diameter of the working chamber should be equal to 1000 mm. The neck has standard sizes that are 700 mm. If the diameter of the pipe is 600 mm, then the neck should be positioned so that cleaning devices can be placed in it. For descent, the working chamber and neck are equipped with brackets and hinged stairs.
State standards for hatches
To a simple layman it may seem that the hatch is not such an important element of the inspection well. But this is not so. The main material for the manufacture of this component is cast iron. Cast iron hatches for manholes are made in accordance with GOST 3634-61. This element has a housing with a cover for installation on the neck, and the diameter of the latter should be equal to 700 mm. The passage openings have a diameter of 620 mm. If there is a need to lay the hatch on the roadway, then its mass will be equal to 134 kg, while the lungs are located on the sidewalks, and their weight is 80 kg.
Hatches of manholes, the GOST of manufacture of which was mentioned above, can also be made of polymer materials, the latter are lightweight, durable, environmentally friendly and durable. When using polymeric materials, fillers are added to the ingredients during the manufacturing process, making the processing impossible. Therefore, such products are not of interest to the receivers of recycled materials.
Well device
In order for the system to function correctly, GOST must be used, manholes are performed according to standards 8020-90. At the initial stage, excavation work is being carried out, which provides for the need to dig a trench and a pit. Before that, specialists carry out preparatory work in the form of marking the territory, demolishing shrubs and arranging an exit to the construction site. After the pit is ready, its bottom is cleaned, the angles of the slopes of the walls are checked with the project, as well as the level of laying. If you decide to use a stone structure, then at the bottom of the pit you need to equip a waterproofing layer, the thickness of which should be 20 cm. Waterproofing can be done using bitumen mastic.
To create a concrete or reinforced concrete well, you need to prepare the base, make a concrete pillow, the thickness of the latter should be 10 cm. You can use the finished concrete slab.
Methodology
Specialists carry out the device tray of the desired shape of concrete with reinforcement in the form of reinforcement. The ends of the pipes should be sealed with concrete or bitumen. The inner surface of the rings is treated with bitumen. As soon as the bottom gains strength, you can proceed with the installation of rings and floor slabs. Then you should grind the joints with cement mortar and waterproof them with the same bitumen. In places where the pipeline will be part of the system, a 30 cm clay lock should be made, the height of which is 60 cm greater than the diameter of the pipe.
Final work
Tests must be carried out during the day, for this the well is filled with water to the upper edge, and plugs are installed on the pipes. This recommendation applies only to sealed containers. Outside, the walls are covered with soil, which is well compacted. Around the mouth is a concrete blind area, the width of which is 1.5 m. The remaining joints should be isolated with bitumen.
Conclusion
If you want the sewage system to work properly, then you should use GOST. Cast iron hatches for manholes, for example, are also manufactured according to state standards, which were mentioned in the article above.