Installation of sewer pipes in accordance with the angle of inclination
In regulatory documents, such as GOST, SNIP, the slope of the pipeline is given in millimeters. At first glance this is strange, because everyone knows from the school bench that the angle is measured in degrees. But for plumbers the slope is measured in units of length, because they will not lay a pipeline with a protractor in their hands, but for them the difference in height between the entrance of the pipe and the point of wastewater discharge is important. Calculation of the height difference is calculated based on the meter length, so the longer the segment, the greater the slope of the pipe.
In addition, the slope value also depends on the diameter of the pipe. Given both parameters, the minimum slope is as follows:
- for a 1 m section and a pipe with a cross section of 50 mm lying in horizontal lines, the slope is 30 mm;
- for a length of 1 m and pipes with a section of 110 mm, which are used to arrange horizontal lines in bathrooms, the angle of inclination is 20 mm.
- for a length of 1 m and pipes with a cross-section of 160 mm, which are used for arranging the external lines, the angle of inclination is 8 mm.
It would seem, what these several millimeters can influence. The difference is not very noticeable in the meter section, but for a pipeline of several tens of meters, the slope will be palpable.
After we have found out what the slope is for, and what this value affects, we should consider the order of the installation of a non-pressure pipeline using a gradient.
The order of installation of the sewerage pipeline
The stage-by-stage installation of the pipeline will be as follows:
- The first lines on each floor of the house are laid horizontal lines.
- Then a fan riser is assembled, combining the horizontal branches into a single system.
- Finally, the external line is arranged and connected to the fan riser.
The main thing in the installation - do not forget about the angles of inclination in the horizontal wiring.
Set the angle in horizontal lines
The installation of a horizontal line with a slope angle is as follows:
- A pipe of a certain length and optimum diameter is selected. Typically, for sewer systems in horizontal wiring take the pipe diameter equal to 50 mm. We look at the normative documents - for this pipe the slope should be equal to three centimeters in a meter section. The length of the pipe is measured already in place of plumbing work.
- Knowing the required normative angle of inclination, the height difference at the beginning of the sewerage is calculated, i.e.under the siphon, and at the point of discharge near the tee of the vertical riser, based on the known length of the pipeline. For example, for a pipe 3 meters in length, the height difference will be 3 mx 3 cm / m = 9 cm.
- After the calculations, we project the data to the place where the sewage system is supposed to be located. However, first you need to determine the height from the branch pipe to the floor. Then the differences in the heights of the slope and the receiving branch pipe are added, we measure the obtained length from the floor and mark the point under the siphon of the shell. This will be the start point of the horizontal pipeline.
- At the end, it will be necessary to find the required length of pipe with a diameter of 50 mm, insert one end into the riser pipe, and raise the other one to the marked height under the siphon.
Guided by established regulations, you will never go wrong in such an important matter as installing a sewer system.