Design features of a viewing plastic well

Sewer pipes are located underground. They need periodic care and monitoring. There are special structures for this - viewing wells. They are especially relevant in the city sewage system - more debris gets there and blockages occur more often. In self-contained home systems, they are also installed for ease of system maintenance.

What is a viewing well

An inspection well for the sewage system is a round shaft through which repair work is carried out and access to the most structurally difficult places is provided:

• inlet and outlet pipes with different cross-sections;
• a change in the slope of the pipe or a large relief drop;
• several small-diameter pipes are connected into one wide line;
• couplings;
• pipe turns or changes in the direction of fluid flow;
• installed pumping equipment or pressure reducers.

On straight sections of the highway, wells are installed in increments of 50 m.

Scope of application

Small diameter shafts are used in home systems. For the city sewage system, wide chambers with steps are used to accommodate two people.

For the purpose of use, wells are:

• Inspection - serve to inspect problem areas.
• Drainage - collect water during the repair of underground utilities, then pump it out from there.
• Regulating - located above the taps and valves.
• For equipment - they contain pumps, sensors, meters, and in some cases heating cables.

Materials for revision wells are chosen depending on where the object is located and what its purpose is.

Types of revision wells and their design features

By design, inspection wells are:

• differential - placed in places where there is a gradual decrease in the level and depth of the pipeline;
• linear - for straight sections;
• rotary - located where the pipes change direction;
• nodal - at the junction of several pipes;
• filtration - for disposal of wastewater through the ground;
• control - at the junction of different types of sewerage.

Drop wells are of several types. They are designed to reduce or increase the speed of movement of wastewater through the sewer pipes. Installed:

• in places where it is necessary to increase or decrease the depth of the pipeline;
• inside underground structures;
• if the difference in heights of the inlet and outlet pipes is more than three meters.

Differential wells are multi-stage, fast-flowing, with a vertically arranged pipe, and stilling wells. They are not used in autonomous private sewage systems.

Filtration shafts are designed for wastewater treatment. Often used in private septic tanks. SNiP norms imply that filtration wells should be located at least one meter above the groundwater level. This takes into account the composition of the soil. For sandy loam soils, the filtering area is 1.5 m, for sandy soils 1 m.

Control - located at the junction of the connection of the local and citywide sewerage system, the factory system and the city, autonomous private and city.

Swivel and nodal shafts help control potentially difficult areas where there are multiple pipe joints or there is a risk of system leakage. The pipes are located at the same level.

Linear ones have one pair of nozzles that are located opposite each other. Designed to control straight sections of the highway located at the same level. The distance between the observation wells is 10 m.

Regardless of the type of construction, inspection chambers consist of the following elements:

• hatch - upper part;
• neck;
• mine - a working chamber, where the foremen go down the steps to carry out repair work;
• tray where the inlet and outlet pipes are located;
• bottom - concrete structure.

Wells are commercially available with different levels of inlet and outlet openings.

Revision shafts are made of materials that are most relevant for this section of the pipeline:

• concrete rings;
• plastic;
• bricks;
• stone.

Most often, concrete and plastic corrugated products are used, since they have a long service life. Specially at the factories of reinforced concrete structures, parts are produced from which mines of various sizes are assembled.

Brick and stone structures allow liquids to pass through and smell diffuse.

The shape can also be different - round or rectangular. The height of the tray depends on the diameter of the largest pipe connected to it.

Actual installation requirements

When arranging viewing wells, special attention is paid to the following parameters:

• In urban systems, the mine must be able to accommodate one adult with a toolbox.
• The main material for the manufacture of hatches is cast iron for urban communications and plastic for private sewerage. The weight of the hatch located on the carriageway is 134 kg, for sidewalks no more than 80 kg.
• The size of the throat should allow the use of cleaning tools.

Compliance with sanitary standards and installation rules allows you to avoid accidents and a breakthrough in the sewage system, as well as create conditions for the uninterrupted operation of the monitoring equipment inside the highway.

Installation steps

To install a revision on a stand-alone pipeline, you must:

1. Coordinate the location of the inspection shaft with the general sewerage plan.
2. Make a markup on the site. If trees or shrubs grow there, as well as there are utility rooms, they are demolished, cleaning the place.
3. Provide transport access if the wells are made of concrete.

When everything is ready, you can start digging a pit along the diameter of the shaft. The bottom is leveled and covered with rubble, tamped. Further:

1. The base is laid - a concrete slab or a homemade screed 20 cm thick.
2. Tray is equipped. The pipes are embedded in concrete and sealed with bitumen.
3. When the structure hardens, you can put the upper part of the rings. The joints are sealed with bitumen after being stacked on top of each other.
4. A floor slab and a neck are installed. All joints are rubbed with cement mortar.
5. In the lower part of the clay, a hydraulic lock is made 50 cm above the nozzles, 30 cm wide.
6. Pipes are connected.
7. After filling the ground, the hatch is installed at ground level or higher.

When installing a plastic well, the sequence of actions is the same, but the weight of the products is much lighter, so a crane is not needed. For a plastic structure, there is no need to make a hydraulic lock, since the product itself is sealed. Due to its light weight, plastic is susceptible to displacement when the ground moves, therefore, in its structure there are special chambers at the bottom where concrete is poured.

Due to constant exposure to a humid environment, products may leak. This happens not because of marriage, but because of improper sealing or its absence. For sealing joints, three types of insulating materials are used - bitumen-polymer, cement-polymer, polymer. A gas burner is used for docking with the main product.

Inspection well prices

The cost of work on the arrangement of revision wells is usually included in the general price list if the sewage system is made at the stage of building a house.Depending on the material and the number of mines, you can make a preliminary calculation of how much the sewage system will cost "according to all the rules" and the economy option. In a difficult area, the lack of access to the highway translates into additional costs for repairs and professional cleaning. Therefore, it is not recommended to save on revisions.

The price for a plastic inspection well of a simple design is usually lower than for concrete products. In addition, there is no need to rent construction equipment. On the other hand, concrete structures are much more reliable when properly installed and sealed.