- №1.Material of internal sewer pipes
- №2.Cast iron pipes for domestic sewage
- № 3.Polyvinyl chloride( PVC) sewer pipes
- №4.Polypropylene sewer pipes
- №5.Polyethylene sewer pipes
- № 6.Copper and steel sewer pipes
- №7.Size and diameter of sewer pipes
- №8.The slope of the internal sewer pipe
We do not see them, but we actively use them every day. We are talking about domestic sewer pipes that connect all plumbing items with a vertical house riser. The quality and durability of the entire drainage system depends on the quality of the pipes, the right material, the diameter and the angle of inclination. In order to decide which sewage pipes to choose for the internal sewage system in an apartment and a private house, first of all it is better to draw up a project for distributing the system, to evaluate the geometry of the room, the height of the plumbing installation and other features.
№1.Material of internal sewer pipes
Internal sewage wiring can be performed using such pipes:
- cast iron. Previously installed everywhere, today is almost never used;
- polyvinyl chloride( PVC);
- polypropylene. Looking ahead, we note that this is the best option;
- polyethylene. Used infrequently;
- steel and copper. Expensive pipes that have not been used, but sometimes are still used due to their appearance.
Despite the fact that polypropylene and PVC pipes are the most common, when choosing, do not rush to immediately discard the remaining options, as in some cases, iron and even copper pipes can be useful.
№2.Cast iron pipes for domestic sewage
A few decades ago, there was no particular alternative to cast iron pipes, so they are massively found in the houses of old buildings. Today, cast iron is being replaced by plastic, but it is still used. Such pipes are made from gray iron by centrifugal casting. To protect the material from corrosion and to make the inner surface smooth, the pipes outside and inside are covered with a bitumen composition. The diameter of the cast-iron pipes ranges from 5-15 cm, the wall thickness is 10-12 mm.
The advantages of cast iron pipes:
- durability. The service life reaches 50 years and often exceeds this milestone. Some data speak about durability in 90-100 years;
- high strength and resistance to deformation. On the other hand, the material does not tolerate shock loads;
- ability to withstand long-term exposure to hot sinks( from a washing machine or dishwasher, for example);
- resistance to temperature extremes;
- fire resistance;
- environmental safety;
- good sound insulation.
Surely, cast-iron pipes would have remained the leaders, if not for , there are significant shortcomings:
- walls overgrown with time by sediment. All because of the roughness of the material, which even a bitumen coating can not be completely eliminated. The process of overgrowing leads to a narrowing of the lumen of the pipe and reduce its throughput. The one who saw how the pipe looks after long years of operation will never forget this terrible sight;
- heavy pipe weight, which complicates transportation;
- complex installation, which is explained not only by the large weight, but also the features of the connection sections of pipes. To sewer system was sealed, you must correctly connect the elements. Usually use the caulking method or caulking with a cabol;
- susceptibility to corrosion processes;
- high cost.
To build a new sewer system, cast iron pipes are not used today, but they may be needed when reconstructing existing systems. At the moment, the use of cast iron pipes is also justified in arranging the outer sections of private sewers and internal risers.
When choosing, it does not interfere with carefully inspecting the products and tapping each of them. Thus, it is easy to detect cracks and other defects that form when the manufacturing process is broken. A pipe with a marriage does not differ in long service life. For connecting cast iron pipes, various kinds of fittings, plugs and sockets are produced.
№3.Polyvinyl chloride( PVC) sewer pipes
For the arrangement of internal sewage PVC pipes are considered almost the most suitable option. In the production process, some other substances are added to polyvinyl chloride, which include stabilizers and polymers. From the heated mass form the elements of the desired shape.
PVC pipes can be of two types:
- plasticized PVC( PVC) pipes have good elasticity and low strength;
- pipes made of unplasticized PVC( PVC-U) are more rigid and resistant to aggressive effects.
Of course, it is better to use unplasticized PVC, but in practice both types of pipes are used. The diameter of products ranges from 2 to 20 cm.
- reasonable price;
- light weight;
- ease of installation. Separate sections of pipes are connected by couplings and connecting rings - everything goes without welding;
- low temperature coefficient of expansion. With a short or constant increase in the temperature of the effluent pipe will not sag;
- sufficient strength and durability up to 50 years;
- sufficient resistance to ultraviolet rays, so that some parts of the pipe can not be afraid to let on the open surface;
- resistance to corrosion and some aggressive substances;
- due to the smooth inner surface with time, the walls do not silt.
- limited temperature range of operation. With constant exposure to negative temperatures, pipes become brittle and lose tightness, and under constant exposure to temperatures above + 60. .. + 700C, the material is able to deform and also loses its integrity;
- insufficient fire resistance;
- inner walls of PVC pipes are smoother than those of cast iron, but over time they will still appear raid. In addition, over the years, the internal diameter changes. As a result of exposure to high temperatures, the round section is transformed into an ellipsoid one, and this impairs the throughput and contributes to the occurrence of a leak;
- Some corrosive substances contained in drains can still lead to the gradual destruction of pipes.
For fitting up the internal sewage system from PVC pipes, appropriate connecting elements are used. Among them knee , adapted to rotate the pipeline at an angle of 20 to 87 degrees, tee for arranging branches, cross for connecting four pipes, and reduction for connecting sections of pipes of different diameters.
№4.Polypropylene sewer pipes
Polypropylene pipes today are actively used in the arrangement of heating systems, hot and cold water. Material properties are highly dependent on its structure. For domestic sewage, pipes made from a copolymer of propylene and ethylene( PPR ) are suitable; they withstand temperatures up to + 700C.The PPs type pipes behave even better, which calmly withstand temperatures up to + 950С and short-term exposure to even higher temperatures. Reinforced pipes will be more durable, and fiberglass reinforcement is considered optimal. In the product labeling, the working pressure is also indicated: PN10 pipes( withstand 1MPa) will be enough for internal sewage, but more often PN20 is taken.
- durability up to 50 years;
- resistance to corrosion and almost all aggressive substances( acids, alkalis and salts will not damage the material);
- high strength pipes and connections. Polypropylene by strength bypasses polyethylene and PVC, it is more resistant to the appearance of cracks, and the joints are less often depressurized;
- light weight;
- absolute smooth inner surface, so that problems with the overgrowing of the pipe will not arise;
- resistance to high and low temperatures, which allows the use of pipes in almost any conditions. The pipes are not deformed;
- relative ease of installation. The connection of individual sections is made by a special welding machine, almost everyone can learn how to work with it;
- is a relatively low price, but polypropylene pipes will cost more than polyvinyl chloride;
- polypropylene type PPs belongs to the group of flame-retardant materials.
Among the minuses of the polypropylene pipes, only thermal deformation can be noted, so they will have to be either warmed or equipped with compensators.
№5.Polyethylene sewer pipes
Polyethylene pipes are used in the construction of domestic sewers infrequently. Usually either low pressure polyethylene or crosslinked polyethylene is used. The first option withstands a maximum of + 400C, so it makes sense to use it only in places with cold drains. Cross-linked polyethylene is designed to work at temperatures of 0. .. + 950C, can briefly withstand temperatures from -50 to + 1200C, therefore, it is usually used. The material has the following advantages. :
- high strength, wear resistance and flexibility;
- corrosion resistance;
- smooth walls and almost complete resistance to the formation of growths;
- light weight;
- resistance to pressure drops;
- flexibility and uncomplicated installation;
- relative availability in terms of price.
- fear of ultraviolet rays;
- through the material can pass oxygen, which will damage the metallic elements in the system. The manufacturer applies a special coating, but it is quite gentle, so when installing it is necessary to behave very carefully so as not to damage it;
- low resistance to abrasion.
№6.Copper and steel sewer pipes
Copper and steel pipes can be called ideal in terms of durability , strength and corrosion resistance. They withstand any indicators of temperature and pressure, are distinguished by a minimum temperature expansion, and have a smooth non-growing internal surface.
The main disadvantage of is the high price. In addition, copper pipes require specific installation, which only a professional can handle.
It is justified to use such an extravagant version of sewer pipes when outdoor installation is carried out, and plastic pipes will look ridiculous. Often, copper pipes are resorted to when they create a retro interior with a leg-bath.
№7.The size and diameter of sewer pipes
Before proceeding with the purchase and installation of sewer pipes, it is best to draw up a project where you specify all the drain points and the type of plumbing equipment. This will help orient with the diameter and length of the pipe needed. At this stage, it also does not interfere with determining the number of auxiliary parts, which will depend on the number of turns and ramifications. Consider and change the diameter of the pipeline in certain areas.
Depending on the type of sanitary device being connected, select pipes with different diameters:
- for a dishwasher and washing machine suitable sewer pipe with a diameter of 25 mm;
- for a bathroom, a shower cabin and a kitchen sink - 40-50 mm;
- for a washstand and a bidet - 30-40 mm;
- for distributing pipes - 40-50 mm;
- bends from the riser - 65-75 mm;
- central riser and pipe from the toilet - 100-110 mm.
To the calculated length is better to add a margin of 10%.
Calculate also the distance from the riser to each drain point: if it is more than allowed, you will have to provide vents and connectors.
Don't forget to purchase siphons. It is desirable that they are from the same material as the pipe, then there will be a minimum of problems with the connection. After the creation of the pipe layout project, the places where the pipe changes direction and forks, as well as the places where several branches are connected, are counted. On this basis, it can be understood how many reducing connectors( for connecting pipes with different diameters), taps( otherwise knees, an element for creating a bend), need to be made from tees and crosses.
№8.The slope of the internal sewer pipe
The sewer pipe can be divided into two sections, vertical and horizontal. Vertical is a riser to which all horizontal pipes are brought, but they can be called horizontal with a stretch. Sewer pipes should be laid under a slight slope to the riser. This is necessary in order to:
- drains quickly go into a common sewer under the action of gravity;
- did not lead to silting of pipes, which occurs when the sewage stagnates in areas without the necessary slope;
- did not cause unpleasant smells and breakthroughs as a result of siltation.
The larger the diameter of the sewer pipe, the smaller the gradient is required:
- for internal sewer pipes with a diameter of 40 mm, a slope of 3.5 cm per meter is sufficient;
- for pipes with a diameter of 50 mm - 3 cm;
- for pipes 80 mm - 2 cm;
- for pipes of 100 mm - 1.5 cm.
If these values are observed, the optimum speed of movement of drains, 0.7-1 m / s, is ensured.
Resist the temptation to make more bias than required. The greater the angle, the faster the drains will leave the apartment. It seems to be good, but this speed brings with it a lot of problems:
- sewage particles, solid food residues and other debris remain in the pipe under the influence of high flow rates;
- is the pipe silting and clogging. The service life of such a system is several times less than that built according to all the rules.
Slope should not exceed 15 cm per 1 meter. It is formed by means of fastenings on which the pipe will be supported, or by creating shtrob in the wall.
In conclusion, we note that the breakthrough of sewage pipes is one of the most unpleasant accidents that can happen in an apartment. That is why saving on the purchase of pipes and their installation is not worth it.