Assortment
There are several types of plastic pipes, namely:
- polyvinyl chloride;
- polypropylene;
- polyethylene;
- metal-plastic.
The features of each of them can be found below.
PVC
Polyvinyl chloride pressure pipes (PVC) used for water supply are made from environmentally friendly food-grade material, while other types of PVC products may contain toxic substances.
UPVC pipes are the most environmentally friendly and safe for human health
Pressure pipes are produced by extracting polyvinyl chloride, to which special components and lubricants are added. The presence of chlorine atoms in the material ensures its self-extinguishing in the event of a fire.
Plumbing made of PVC plastic pipes can transport liquids up to +40°C. If the air around is cooled to 0 ° C and below, then the structure must be insulated, since under such conditions the material loses its elasticity and may collapse.
The average price for PVC-U plastic water pipes is 10 rubles per meter.
Polypropylene
Polypropylene pipes for water supply are extremely durable, resistant to abrasion, flexible, withstand temperatures down to -25°C and are practically unaffected by surfactants. These qualities allow them to serve a guaranteed term of 50 years.
Polypropylene plumbing without harm to the material is able to supply liquids with temperatures up to + 75 ° C, and in the short term - up to + 95 ° C.
Polyethylene
Plastic pipes for water pipes made of polyethylene function in the temperature range of 0–+40°C. They are absolutely harmless and do not affect the quality of transported drinking water.
Polyethylene will keep the water for you in its original state
Depending on the difference in the production process, five types of polyethylene products are distinguished:
- HDPE (low pressure);
- PSD (medium pressure);
- PVD (high pressure);
- PEX (crosslinked).
With their help products with different characteristics and scope are obtained.
metal-plastic
Metal-plastic pipes are a structure of three layers:
- inner layer made of cross-linked polyethylene;
- aluminum foil with a thickness of not more than ½ millimeter;
- polyethylene protective cover.
The guaranteed period of their operation is 30 years, and their operating temperature in the long term reaches 95°C. Safe operation for several hours at 110°C is also possible.
Such a product is able to withstand internal pressure up to 10 atmospheres.
Metal-plastic withstand very high pressure and are boldly used in production
Is it possible to use plastic pipes for heating
Plastic quickly loses its technical characteristics when exposed to high temperatures. Therefore, when choosing plastic pipes for heating, you need to select products that meet a number of requirements:
- Plastic must withstand the temperature of the coolant. The maximum temperature is 95 degrees. At this temperature, the pipes should not deform.
- The pipes must withstand high pressure so that the water hammer that occurs in the system cannot destroy the pipeline.
- Minimum coefficient of thermal expansion. Otherwise, individual elements of the pipeline will sag when heated. When the temperature drops, internal stresses can occur, which adversely affect the strength of the tubes.
- Pipes must be even on the inside. If this requirement is not taken into account, plaque will accumulate on the inner walls, which will lead to blockages.
- Pipeline elements should not be destroyed by various chemicals that may be contained in tap water.
- The individual elements from which the heating circuit is assembled must be durable in order to function for a long time without breakdowns.
- The pipes must have a high sound insulation value so that the flow of water is not heard in the rooms.
Marking
There are several types of plastic used for the manufacture of pipelines:
- PVC pipes;
- polypropylene products;
- polyethylene parts.
A separate group includes tubes, in the manufacture of which a reinforcing layer of aluminum foil or fiberglass is placed between the plastic layers.
The marking varies depending on the type of polymer. It makes no sense to describe the designations on PVC, since this material is not used for the manufacture of water supply and heating pipelines. This type of polymer emits harmful substances when heated, has low performance characteristics.
Polyethylene marking:
- PE 32 is the type of polyethylene with the lowest density index. It is rarely used for the manufacture of pipes.
- PE 63 - used to assemble non-pressure systems. It can be sewage, summer shower. This type of polyethylene does not withstand high pressure, is destroyed by water hammer.
- PE 80 is a type of polyethylene with a high strength index. It is applied to assembly of systems of cold water supply. If the pipeline is laid outside buildings, additional insulation must be used.
- PE 100 - pipes made of this type of polyethylene have the highest strength index. Are applied to production of industrial pipelines, systems of hot, cold water supply, heating contours.
The marking of polyethylene pipes contains the abbreviation SDR, followed by numbers. The lower this indicator, the stronger the product.
Marking of polypropylene tubes:
- PN10. Products with this designation can withstand pressure up to 1 MPa. Permissible liquid temperature - 45 degrees Celsius. Due to the low strength and thermal stability, such tubes are used to assemble sewer drains, cold water supply pipes.
- PN16. The maximum allowable pressure level is 1.5 MPa. The coolant temperature should not exceed 60 degrees. Popular for the manufacture of cold water systems. Rarely used for assembling hot water circuits.
- PN20. Tubes made of this type of polypropylene withstand pressure up to 2 MPa. The maximum allowable coolant temperature is 80 degrees. It is applied to assembly of systems of hot, cold water supply, heating contours.
- PN25 is the most durable type of polypropylene. Such material can withstand pressure up to 2.5 MPa. The temperature of the coolant can rise up to 95 degrees. Withstands temperature fluctuations - up to 110 degrees.
Labeling of multilayer products:
- PPR - the outer layer of the tubes is covered with polypropylene;
- AL - has a reinforcing layer of aluminum foil;
- PP-RCT is the designation of modified polypropylene, which has increased thermostatic properties.
If there is a fiberglass layer inside the pipe, the marking will contain the letters FG, FR.
Polypropylene heating pipes
Installation
Assembling a plastic water pipe with your own hands is a simple matter, but it requires strict adherence to all the rules. The whole process consists of two stages: preparation and assembly.
The first stage involves the construction of a pipeline diagram and the selection of tools. The scheme is carried out in the form of a drawing or as markings on the walls of a room. When compiling it, it should be borne in mind that the internal water supply system consists of several elements: a distribution line, an inlet, a water meter unit, risers, shut-off, control and water fittings, as well as pumps and tanks.All of them should be marked on the diagram. Such a measure will allow you to choose the most successful location of the water supply network and avoid installation errors.
The selection of tools is carried out depending on the type of materials used and the method of laying them. You may need:
- fitting;
- apparatus for welding;
- support;
- pipe cutting tool.
Installation of water pipes from each type of plastic has its own characteristics.
The assembly of metal-plastic pipes is carried out in two ways: press and collet. The pressure connection of water pipes is carried out using press tongs and a crimping press. This method is considered the most reliable, but requires expensive equipment and fittings. The collet fastening is made by brass fittings of the same name. Thanks to this method, water pipes made of plastic pipes can be easily dismantled if necessary. But under the influence of elevated temperatures, the connection may be broken, so its condition should be checked periodically, and if necessary, replace parts.
Polypropylene plastic pipes are fastened by welding. With the help of a special apparatus at a certain temperature, the pipe is heated at the junction from the outside. Next, the heating element is inserted into the plastic fitting for a while, after which the pipeline parts are neatly connected.
Fastening of plastic pipes is carried out using special welding
During the process, it is important to strictly observe the temperature regime and duration, since underheating does not ensure effective sealing, and overheating deforms the parts. The value of the parameters depends on the diameter and thickness of the product is presented in special tables
Do-it-yourself installation of PVC pipes is possible in two ways - in a socket or by cold welding.
The first method is extremely simple and consists in connecting the elements in series using a rubber ring as a seal.
Installation of water supply pipes using the cold welding method is as follows:
In order to make sure that the dimensions of the parts correspond, it is necessary to connect them “dry”.
- The edges of the pipes are processed with a file or a special knife.
- The elements at the joints are coated with a primer, which cleans and prepares the surface for the most effective interaction with the adhesive.
- A special aggressive adhesive is applied to the outer edge of the pipe and the inner part of the fitting, which changes the structure of the upper plastic layer, ensuring the interpenetration of the molecules of the contacting parts. Thus, a reliable fixation of parts is obtained.
To connect a plastic and metal pipe, a spiral double adapter is used, on one side of which there is a thread for a metal part, and on the other - a smooth end for plastic.
supports
The choice of support is a responsible task. It provides the support that plastic pipe plumbing needs, increases the quality of its functioning and service life.
Supports are of several types:
- motionless;
- mobile;
- sliding;
- collar.
The fixed support supports the structure from below and prevents movement.
A movable support for water pipes protects pipes located above the ground from the effects of negative weather conditions and elements (seismic activity, wind, etc.). Thanks to this support, the pipe does not sway vertically, but is subject to moderate vibrations.
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A sliding support for water pipes supports the pipeline and helps to distribute the pressure exerted on it.
Sliding clamp support for pipelines is made of steel. It provides them with solid support, but provides for some expansion or vibration of the elements. Plastic pipes for plumbing
Characteristics of plastic pipes for water supply
The modern market for water pipes offers a huge selection of plastic products of different types and properties. But, despite some differences between them, there are certain signs that characterize plastic pipelines.
Advantages
Plastic pipes for water supply have the following positive qualities:
- rust resistance;
- guaranteed service life up to 50 years;
- low degree of thermal conductivity;
- flexibility;
- elasticity;
- light weight;
- ease of installation;
- lack of electrical conductivity;
- wide application indoors and outdoors;
- the ability to soundproof;
- smooth coating of the inner surface prevents the deposition of insoluble substances on the walls and clogging of the passage;
- lack of reaction with aggressive chemical environments;
- unsuitability for the development of bacterial flora;
- wide operating temperature range - from -100°C to +95°C.
These features allow plastic communications to be used even in conditions of freezing of the transported liquid. Their integrity in this case will not be violated.
Plastic pipes will really save your budget
Flaws
Among the minuses, it is worth noting the limitation of the operating temperature to + 95 ° C. But this feature is not critical for water pipes, since the transported liquid rarely reaches such a maximum mark.
Plastic water pipes cannot be used in fire protection systems. They should not be located near potential sources of ignition, as some of them are highly flammable.
