Plastic pipes, their types and characteristics. Rules for the selection of products for plumbing systems. Features of structures made of polymeric materials.
Plastic pipes are the general name for products made of polyethylene, polypropylene, polyvinyl chloride and metal polymers that are used to create water supply systems for apartments and houses. The industry produces such samples in a large assortment for the installation of structures in various conditions. The article provides information on popular types of plastic pipes for water supply systems, which will be useful to users.
Read separately an article about the installation of plastic pipes for water supply
Features of plastic water pipes
Plastic pipes were created from polymers thanks to the development of modern technologies. They are gradually replacing metal counterparts due to improved performance characteristics. There are several types of plastic pipes that differ in properties and installation methods (see table below).
|Polyvinyl chloride||For supplying cold water outside and inside buildings||After installation, a rigid structure is formed|
|Polypropylene||Cold and not very hot water supply outside and inside buildings||The pipes consist of three layers, have a large linear expansion, and are not flexible enough for a complex route|
|Polyethylene||For supplying cold water outside and inside buildings||Very flexible products, performance deteriorates at low and high temperatures|
|Metal polymer||Cold and hot water supply outside and inside buildings||Retain their shape after bending, withstand very high pressure|
Despite the different properties of the materials from which the pipes are made, the products have a lot in common:
- With proper installation and maintenance, the operation of plastic pipe systems can last 50 years, which is many times longer than the service life of metal counterparts.
- Cavities are not clogged with salt and other deposits, the surface does not rust. But this does not guarantee perfectly clean water from the tap, so a filter at the outlet of the system is required.
- The products are lightweight, 3-10 times lighter than metal ones. They do not place any special stress on other structures.
- Modern samples are made from environmentally friendly material that does not pollute the soil and does not degrade water quality.
- The dense material dampens fluid flow noise.
- Installation of a water supply system from such products is simple, it can be done without assistance.
- Pipes can be laid on any route, and no complicated equipment is required for turns.
- They tolerate large temperature changes well, do not burst when freezing and do not swell when heated.
- Products do not require special conditions for storage and transportation.
- The price of plastic pipes for water supply, in comparison with metal samples, is low.
To keep the system operating as long as possible, follow our recommendations when choosing products:
- Before starting work on the construction of a water supply system, develop a pipe layout on the site, which will take into account all the subtleties and nuances of the environment. According to it, it will be possible to determine the amount of consumable material, the diameter of the samples, the type of product that is optimal for a particular case. Consider the length of the blanks with a margin, taking into account possible rejects.
- Before you buy plastic pipes for water supply, study their main characteristics: diameter, thermal expansion, working pressure, fluid temperature, chemical resistance. The service life of the system depends mainly on the combination of the pressure of the working medium and its heating. The higher they are, the faster the structure will fail. If the pressure is low, and the temperature is high (or vice versa), the water supply system will last as long as possible. Manufacturers guarantee a long service life of the system even at a water pressure of 4-5 atmospheres and a temperature of 65-70 degrees. In some types of pipes, for example, polypropylene, the wall thickness of the product affects the service life.
- When purchasing, find out the linear expansion of the samples, especially if they are used in a hot water system. For example, 1 meter of polypropylene pipe increases in length by 9 mm when heated by 60 degrees. Therefore, consider in advance the possibility of free movement of the composite elements. Otherwise, internal stress can damage the structure.
- Reinforced-plastic products practically do not lengthen when heated, but there may be a problem with fittings that connect adjacent cuts. Therefore, there must always be access to the joints of the parts to control their condition.
- The throughput of the system depends on the diameter of the pipe. For ordinary plumbing, buy products with a diameter of 11 to 21 mm, for risers - more than 25 mm.
- The size of plastic pipes for plumbing is also affected by the number of turns and bends in the structure. If there are few flat areas, add larger diameter samples to avoid problems with fluid flow and pressure.
- Plastic pipes that are planned to be used outside the building must be insulated. The method of thermal insulation and the material is chosen depending on the climatic zone and the average temperature in winter.
- Products have great strength, but if the line is not properly assembled, even they will collapse. In most cases, the trouble occurs in extended systems in which there are no temperature compensators.
Sizes of plastic pipes for water supply
Plastic pipes for water supply are made from petroleum products and their derivatives. However, despite the common raw materials, there is no universal brand of products. At the production stage, special additives are introduced into the composition that change the properties of finished products.
On the territory of the CIS, 4 types of plastic pipes for water supply systems are produced according to their own GOSTs: metal-plastic, polypropylene, polyvinyl chloride and polyethylene. Each species has its own range of sizes, shown below.
The sizes of plastic pipes for water supply are presented in the table:
|Pipe type||GOST||Application||Diameter, mm||Wall thickness, mm|
|Polyethylene (PE)||GOST 18599-2001||Light pipes||20-110||2, 0-29, 3|
|Medium pipes||2, 0-45, 3|
|Heavy pipes||2, 0-45, 5|
|Polyvinyl chloride (PVC)||GOST R 51613-2000, GOST 32412-2913||Drainage from bathtubs and sinks||10-315||1, 8-6|
|Toilet drain||from 100|
|Drain from washing machines||25-32|
|Reinforced plastic||-||Plumbing installation||15, 20||2|
|Sewerage||40, 48||3, 9, 4|
|Polypropylene (PP)||GOST 32415-2013||Internal communications||40, 50, 110||8, 1|
|External communications||from 150||32, 1-35, 2|
Next, we will consider the types of plastic pipes for water supply and their features.
Varieties of plastic pipes
Plastic pipes for plumbing differ in physical properties due to different chemical compositions of materials. A brief description of the products most used in systems is given below.
They are the first plastic pipes that began to be used to create plumbing structures. Marked with the letter designations PVC or PVC. They have an aesthetic appearance that allows you to lay branches without masking. Installation can be carried out in an open and closed way. Such pipes are inexpensive.
Additives are often added to the composition of the material, which change the properties of pipes and increase the scope of their application.Products burn poorly, have increased chemical resistance.
The wall thickness of PVC pipes for water supply (GOST R 51613-2000, GOST 32412-2913) is shown in the table:
|Diameter, mm||Wall thickness (S), mm|
|63||3, 8-10, 5|
|75||4, 5-12, 5|
|110||6, 6-18, 3|
They can be used in any climatic conditions, but it is recommended to use them in a cold environment. They are not intended for hot water supply, as melt at a temperature of + 50 + 60 degrees. The optimum temperature for operation is up to +45 degrees. In cold weather, they become fragile.
Unlike other types, the cuts can be connected together with sanitary glue and rubber cuffs, which are installed in special grooves. However, the pipes are quite rigid; you can only change the direction of the route with the help of corners.
Pipes that tolerate low or high temperatures well are collected from samples made from chlorinated polyvinyl chloride (CPVC). Products made from this material can even be used to supply hot liquid to radiators.
Polypropylene pipes for water supply
They belong to universal designs that are not afraid of cold and hot water. The pipes are produced with a diameter of 16-125 mm. Sold in 4 m pieces regardless of diameter. They are PP marked.
These are lightweight and durable samples produced in two versions - with or without reinforcement. Single-layer products are very flexible and soft, therefore their use is limited to use in low-pressure systems for supplying cold water. To get rid of this disadvantage, manufacturers began to produce pipes with reinforcement, characterized by a multilayer structure. The inner layer is a thick-walled polypropylene pipe, the middle layer is aluminum foil, the outer layer is a protective polypropylene layer. Such samples are used both for watering the site and for creating a water system inside the house.
Polypropylene pipes are available in three types, designed for pressures of 10, 16, 20 atmospheres, which can be distinguished by wall thickness. Also on sale there are products with improved thermophysical properties.
The wall thickness of polypropylene pipes for water supply (GOST 32415-2013) is presented in the form of a table:
|Diameter, mm||Wall thickness (S), mm|
The parts are connected by thermal welding, after which the entire line turns into a monolith. Installation of a water conduit made of polypropylene pipes must be done carefully, because the welding procedure is very responsible - the material is easy to overheat. After exposure to elevated temperatures, the strength of the structure decreases.
Polypropylene pipes have different colors - gray, white, black, green, which indicate the difference in their characteristics. For example, blacks tolerate ultraviolet light well.
A significant drawback of polypropylene structures is their rigidity - the assembled line bends slightly. To change the direction of the route, use corners and tees.
Marked with the letters PE. The diameter of plastic pipes for this type of water supply is in the range of 15-160 mm. Blanks are sold in coils of 10 m or in cuts of 12 m. Long blanks allow you to create areas without joints and increase the tightness of the structure.
The industry produces high pressure pipes (LDPE) and low pressure pipes (HDPE). HDPE products are used to supply drinking water. They can be easily identified by their black color. Occasionally there are specimens with distinctive blue stripes on the surface. Polyethylene acquires black color after adding light stabilizers and soot to its composition, which increase the resistance of pipes to sunlight.
Wall thickness of polyethylene pipes for water supply (GOST 18599-2001):
|Diameter, mm||Wall thickness (S), mm|
The products can be installed in systems for any purpose, but they have proven themselves especially well for supplying cold water (0 … + 40 ° С). The high temperature increases their flexibility, which can cause the branch to break.At -20 ° C, the material becomes brittle. This property must be taken into account when using the system in winter.
Products made from this material are very elastic and easy to assemble. However, the assembly of polyethylene pipelines has its own peculiarities associated with a change in the properties of the material with decreasing temperature. It is not allowed to assemble the system if the air temperature is less than + 5 ° С. Connect the samples to each other using electric welding and crimp fittings.
One of the modifications of polyethylene is called cross-linked polyethylene (PEX). These pipes are manufactured under pressure, which improves their properties. In contrast to the first variant, in cross-linked polyethylene, the linear sections are interconnected by cross-links, forming a three-dimensional network structure. The product acquires new qualities - increased mechanical strength, resistance to high temperatures and frost, resistance to cracking, impact, chemical resistance. They are often used in hot water supply systems. Fittings are used to connect the parts. The disadvantage of such pipes is their high cost. Pipes are produced from cross-linked polyethylene with a diameter of 12 to 315 mm.
Metal polymer pipes for water supply
The products have a multilayer structure: in the middle there is an aluminum or copper foil with a thickness of 0.2-0.5 mm, outside and inside there is a plastic coating. The foil between the plastic gives strength to the product and reduces its thermal deformation.
To distinguish from other products, reinforced-plastic pipes are marked with the designation PEX-AL-PE or the like, depending on the composition of the layers. The first letters denote the material of the inner layer, the last one for the outer layer. In our case, the marking means that the pipe consists of XLPE, aluminum foil and regular polyethylene.
Products are produced with a diameter of 16-40 mm. They are marked in two sizes: 12-15 mm, 20-25 mm, etc. These values indicate the outer and inner diameters of the product and are needed to select a fitting for joining them.
The wall thickness of metal-plastic pipes for water supply systems is presented in the table:
|Diameter, mm||Wall thickness (S), mm|
Pipes made of metal-plastic are designed for cold and hot water supply, withstand pressure up to 10 atm, slightly lengthen when the temperature rises. They can be operated for a long time at a temperature of + 95 ° С and for a short time - at + 110 ° С. The workpieces retain their new shape after deformation, which is very convenient when pulling along a complex path.
Such pipes are connected to each other in two ways:
- Press docking… Differs in reliability and is used both for external laying, and in a cavity or strobe. However, this method requires special expensive equipment.
- Collet connection… Reminds the way of fixing metal products to each other. But due to temperature fluctuations, the joints weaken, and in these places a leak may occur. Therefore, after the first year of operation, it is recommended to additionally extend the route made of metal-plastic pipes with collet fixation of parts. Due to the low reliability, pipelines with collets are mounted on the surface or in places with a good approach to the joints.
Price of plastic pipes for water supply
The cost of plastic pipes for water supply is influenced by many factors, but the following are considered the main ones:
- Manufacturing technology… Plastic is a modified plastic that is produced from petroleum products. The individual properties of the material appear after the introduction of special substances into its composition using special technologies.
- Versatility… Products that are used only in cold water pipes are much cheaper than those that are not afraid of high temperatures.
- Distance from the place of production to the consumer… The pipelines are of considerable size, so the cost of transportation is also included in the price.
- Workmanship… Most plastic pipes are connected by soldering, which requires high precision in the manufacture of pipelines and fittings. Such requirements are provided only by high-quality expensive equipment that large companies have. Well-known brands guarantee the high quality of their products, so their prices are always higher.
Prices of plastic pipes for water supply in Ukraine:
|Pipe material||Price for 1 m, UAH|
Prices of plastic pipes for water supply in Russia:
|Pipe material||Price for 1 m, rub.|
How to choose plastic pipes for water supply - watch the video:
Plastic pipes have filled a niche in the plumbing industry. They are more than successful in conquering the market, replacing short-lived and expensive metal products. With the right choice of blanks and adherence to the installation technology, they will not have to be repaired throughout the entire warranty period.