Why are sewer hatches round - is it a necessity or a tradition?

Why are the sewer hatches round? And what else can they be? Theoretically, the hatch can be either square or rectangular. But such a design, rather, is an exception to the rules. Luke - this is not a simple laz, it must be reliably closed. It should be easy to maintain and safe to operate.

If convenience is an amateur, reliability at the level of standard loads can be provided by a round cover design. From its shape depends the configuration of the base, which, in fact, is the sewer hatch.

Sewage system

Sewage networks - a complex of facilities designed to collect and drain sewage from users to treatment facilities. The easiest way to do this is through underground communications. Digging a trench, it is laid pipes, which will be drained.

To be able to service the system after a certain distance, inspection shafts are needed. In an urban infrastructure with dense buildings, the ability to conduct sewage networks is only along roads or directly below them. In this case, with intensive vehicular traffic, hatches must be securely closed. But why are the sewer hatches round? They must have sufficient strength to withstand the maximum possible transport loads.

In a large city, the number of inspection hatches and all kinds of mines can be hundreds of thousands. After all, this is not only a sewage system, it is also a network of communications: water supply, heating systems, electricity, gas, telephony and so on.

Inspection wells

For ease of access to communications, the shaft of a well is usually made of a circular shape. Sewer rings, used for the erection of such structures, are most often made of reinforced concrete.

The cylindrical shape of the well is most suitable for maintenance. In such mines it is more convenient to work. They are suitable for ventilation, as the air circulation in the object of the cylindrical shape occurs more intensively.

The lid size, base area and inner diameter are selected in accordance with the purpose of the inspection shaft. In this case, all the elements of the system will correspond to each other as much as possible. The location, possible loads, traffic intensity are taken into account.

Why are the sewer hatches round?

It depends on the shape of the lid. On the one hand, maintenance personnel should have convenient access to underground communications. On the other hand, the well must be securely closed to prevent foreign objects from entering, to ensure the safe movement of pedestrians and the passage of transport. The round lid is best suited for this, which means that the hatch itself should be of this shape.

Depending on the purpose, they are divided according to the type of communications laid under them: engineering cable networks, water supply, gas mains, heating mains, storm and sewerage. The size of the sewer hatch in different countries is different. In Russia, standard dimensions (645 and 800 mm) are most often used. Hatches, manufactured not according to GOST, are designed and developed by manufacturers in accordance with the order and specific technical conditions.

Why is the hatch cover round?

This configuration has a number of advantages. Earlier hatches were made in various shapes. They could be square, rectangular, oval and even triangular to indicate the direction of water flow. However, the round shape of the lid was most suitable.

It will never fall into the well, as if it was not cranked. The round cover is easier to open, so the point of application of force anywhere in the circle will be the same. You can roll it by placing it on the edge. In the manufacture of such a structure is economically more profitable.

The round shape of the lid is less prone to subsidence. It withstands a large load at the same thickness, and therefore, it can be made thinner without loss of quality. In the production of round castings give a smaller percentage of rejects (shells, pores, caverns).

Material

The base and hatch covers for responsible sewer wells are most often made of cast iron. This material has strength, which makes it possible to withstand heavy loads, and corrosion resistance for a long service life. The weight of the structures is sufficient so that the passing transport can not accidentally raise and move the cover. Cast-iron hatches are made when remelting secondary raw materials, they are cheaper than steel analogues.

In places where there is no intensive traffic, it is not advisable to install heavy and powerful structures. Recently hatches of plastic, polymers and composite material have appeared. They are lighter, cheaper, have a sufficient margin of safety, a long service life.

In private houses for equipping sewerage, equipment of inspection wells and septic tanks use sewer pipes made of reinforced concrete. In this case, it is justified to install on them the same base for the hatch. The lid is also made of concrete. It is made of a larger diameter, does not enter the groove, but simply covers the opening of the hatch. The massive construction is heavy enough that it can not be accidentally moved. This ensures the necessary safety during operation.

Specification and marking

For heavy loads on the roads use heavy hatches (class T). They can have a weight of more than 100 kg and a thickness of more than 100 mm. Where no traffic is provided, use light hatches (class A). Designs for the garden, lawn and other areas (Class A) have a diameter of 540 mm and a thickness of 50 mm.

Why are the sewer hatches round and marked? This is done for the convenience of recognizing their belonging to public services. On their covers there are letters: HS - gas network, MG - main gas pipeline, NG - fire hydrant, etc.