At least once in his life, a person working with his own hands came across sewer pipes made of polymeric materials and assembled a drainage system. Fortunately, the sewerage assembly method "pipe - socket " are very simple and even primitive with which it is easier to deal with "steamed turnips"
For this reason, many are engaged in laying this pipe, without having elementary knowledge of how to assemble it correctly. My task in this article is not just to say how to assemble, but to tell what physical processes occur when a liquid passes through pipes and fittings at different angles.
If you ask a question on the Internet at what angle to lay sewers with a diameter of 50 mm and 110 mm, then we can get the answer that for a pipe of 50 mm the condition applies: for one meter of pipe, a slope of 3 must be observed cm. And for a pipe of 110 mm 2 cm. The question arises? And where did these calculations come from, they took them from SNiP 2.04.03-85 and SP 32.13330.2012 and these documents were not "fools".
So, we know the angle of inclination of the pipe. And what happens if they are not followed?
First case: Negative sewer slope or lack thereof.
Sometimes in apartments you can find an option when the sewer tee is raised high from the floor level, naturally this situation should be corrected. But sometimes they don't pay attention to this moment and the sewer pipes have almost no slope to the central riser, which leads to stagnation of sludge in the pipes and frequent blockages. In addition, liquid begins to flow through the glands of the sockets. Therefore, always maintain a slope of 2-3 cm per meter of pipe, depending on the diameter.
Second case: a large slope of the sewer pipe.
Let's say you need to raise the toilet from the floor level, for some reason, in this case you need to follow the rules, or the liquid and feces float smoothly, or immediately "fall:
But usually they apply the rule, cheap and cheerful, they lay the route along the shortest path, what cannot be done, this is what it will lead to
In such a pipe, the velocity of the liquid increases, and the harder "sludge" does not keep up with it, so it is smeared "on dry" along the pipe. Over time, due to a lack of liquid at the bottom point, a blockage may form.
Conclusion: When I started my practice as a plumber, my mentor explained this procedure in this way: "Waste products should float in the pipe, gradually propping up liquid. If the water runs away faster (large slope) or lags behind (small slope), then problems are assured.