The correct slope of the sewer pipe is a guarantee of its self-cleaning

For the name of the sewer, the word "cloak" is sometimes used, which in parallel has one more meaning: an incredibly dirty place. Unpleasant, of course, but this is reality. The physiological and everyday life of a person is accompanied by an extremely large volume of waste. And far from all of them the sewage system, through which they are utilized, can "digest" without consequences.

For example, any residues of fatty foods are likely to remain on the inner walls of sewer pipes, especially if they are cast-iron tubes that are roughened inside. A new portion of fatty waste will stick to this sticky raid, and so on. So the sewage pipes grow from inside.

The means of combating the blockage is the slope of the sewer pipe, which provides the effect of self-cleaning of the system. This effect is based on two physical phenomena: gravity and hydraulics. The gravitational field of the Earth attracts to its center all objects on the planet, including sewage. If, prior to determining the degree of filling the system with sewage, to ensure that they move through the pipes at a certain rate, these waters will themselves counteract the accumulation of waste within the pipes.

The speed of the flow of sewage within the system and the level of filling of the system are inversely proportional to each other. If you increase the slope of the sewer pipe, simultaneously with the reduction of the filling of the system, the speed of the water flow will increase, and vice versa.

The larger and more complex the size of a dwelling, the greater the number of plumbing fixtures in it, serviced by a branched sewage system. In such conditions, when it is necessary to ensure the optimal angle of the slope of the pipe, a vertical method of laying pipes (ie at right angles to the floor level) is used. Many prefer to use cast-iron pipes for sewerage: traditionally, because of the strength and impressive durability (up to 80 warranty years). However, because of their high cost and high metal content, as well as the considerable weight complicating the installation, they are increasingly choosing to use plastic pipes.

Optimal is the slope of the sewer pipe, which connects the plumbing device and the common sewer pipe of the internal system at an angle from top to bottom. But to lower the pipe below the level where the internal system is connected to a common sewerage network is impossible.

The optimum slope is also affected by the diameter of the sewage pipe: 2 degrees - for 85-100 mm, 3 degrees - for 40-50 mm.

In any case, it is necessary to focus on the optimal speed of sewage water flow in the system (0.7-1 m / s). This is important, since exceeding this speed leads to a decrease in the self-cleaning effect due to the separation of streams and the retardation of solid particles. In addition, the noise level during the flow is increased, which is especially critical for plastic pipes that are not protected by noise insulation.

A gross mistake is the connection when installing sewer pipes made of different materials. This means that under the influence of heat, they will expand differently. As a result, not only the slope of the sewage pipe is broken - the entire system can be disabled.

Calculating the speed of water in the sewage system is reduced to finding an equilibrium between the wear of pipes and their overgrowing. This value is called in hydraulics the economic speed.