With the advent of plastic products on the building materials market, their scope is gradually increasing. And most often people give preference to PVC pipes, using plastic structures in everyday life to equip their apartments and houses. Namely – for the construction of power grid and water supply systems, as well as heating, sewerage, ventilation. Therefore, the majority of potential consumers have a painfully relevant question: “What is the real shelf life of plastic pipes and what does it depend on?”
How long do PVC sewer pipes last?
Users planning the implementation of an engineering project using plastic pipes are interested not only in the description of products and their technical characteristics but also in the actual service life of the installations. And if we take PVC collectors as an example, then their warranty period of service is 50 years (if you believe the manufacturers’ statements).
However, in fact, this indicator is conditional and depends on several factors at once:
- A kind of plastic
- Environmental conditions
- Media temperature
- System pressure.
With optimal permissible performance, the products may well serve during the warranty period declared by the manufacturer. Otherwise, the service life of PVC pipes can be significantly reduced. So, for example, if at a temperature of the supplied substance of 50⁰С and an allowable pressure of 11.7 kg s / cm² the durability of the material will be the declared 50 years, then at the same temperature and pressure of 12.8 kg s / cm² the product will be able to maintain its operational properties only for 25 years. That is why it is so important to know what area of application and conditions of use for each specific model.
Today the market of plastic products is represented by designs of various modifications, which are actively used by humans in everyday life. And, depending on what raw materials were used in their production, it will be possible to judge the service life of a particular model in specific conditions.
So, the most common are PVC plastic pipes. Their service life usually varies from 20 to 100 years. Such pipes are laid when arranging water supply networks: for supplying water to a building and when installing internal fluid supply systems. These plastic products can also be used in heating, ventilation, sewerage systems, and as insulation for cables and wires. At the same time, for each individual sample, the manufacturer sets certain operating standards.
How long will the products last in the sewage system
Increasingly, when arranging sewage models, it is precisely PVC plastic pipes that are used . They may well be considered a high-tech development of our time, because such installations are distinguished by their reliability and a number of advantages.
Among the main advantages of PVC products:
- Safety, non-toxicity, and non-flammability of raw materials.
- Practical to use and when laying highways.
- Low weight.
- Long-term operation without clearing blockages.
- Absolute neutrality to corrosion, aggressive substances.
- Resistance to the effects of various living microorganisms.
- High indicators of durability.
The service life of PVC sewer pipes, according to manufacturers, is more than 30 years. However, when purchasing such PVC products, it is necessary to take into account the conditions under which the pipeline model will be operated and what potential factors of influence on it exist. For example, it is necessary to take into account the susceptibility of collectors to manifestations of the external environment (weather conditions, ultraviolet light, etc.) and indicators of humidity in the room. It also does not hurt to assess the likelihood of mechanical impact from the outside and the risk of microorganism growth inside the system.
Usually, the durability of PVC collectors corresponds to the warranty period, if the products are used in optimal conditions, and the temperature of the carrier does not exceed + 75 ° C. At the same time, the pressure in the system should not exceed 4-6 atm.
If a liquid with a temperature of about 70 ° C is constantly transported through the system, and the structure itself is regularly exposed to mechanical stress, its service life will significantly decrease.
In this regard, PVC products are inferior to polypropylene, which, in turn, are more resistant to high temperatures and aggressive environments. The service life of plastic sewage pipes made of polypropylene reaches 50 years in networks with a medium at the room, cold temperature, and 30 years – if the carrier is supplied with a temperature of 80-90⁰С.
Permissible period of operation of polyvinyl chloride water pipes
Manufacturers of PVC manifolds for cold water pipelines estimate the durability of their products at 55-60 years. In order for such materials to be able to serve for the specified period of time, they will need to be operated at a temperature of 65 to 75 ° C and with maximum pressure in the system of 4-6 atm. The supply of water with a temperature of about 20 ° C at the same pressure also ensures the full warranty of the life of plastic water pipes.
Plastic collectors are produced by manufacturers in various modifications, which contributes to the expansion of their field of application. At the moment, on the market of materials for communication systems, you can find products with an inner diameter in the range of 90-630 mm. Among them, there are materials that can be operated at maximum pressure in the system up to 16 Bar. At the same time, such models are notable for their low price and practicality of use.
Other advantages of PVC plumbing manifolds include:
- Excellent throughput due to the smoothness of the surface of the raw material.
- Ease of joining segments and assembling structures.
- Resistance to chemically aggressive substances, corrosion, ultraviolet radiation.
- Affordable price.
When using such products, the formation of deposits and the multiplication of microorganisms in the system are excluded. And also such products do not support combustion, which makes them safe for human use in everyday life.
The service life of a PVC water supply system depends on the pressure under which the liquid will be supplied to the network and what its temperature will be. The conditions in which the pipes will be laid and further used also affect the operational term of the products.
When laying underground water canals made of PVC pipes, one should pay attention to their low resistance to mechanical factors. Therefore, in order not to deliberately reduce the operational life of the materials, it will be necessary for advancement to provide additional protection for the structure in the form of foam boxes and other similar installations.
You also need to remember that at an ambient temperature less than -15⁰С without additional insulation, it is strongly not recommended to use PVC pipes. The service life of products in such conditions will dramatically decrease, and you will be forced to replace the system. Such nuances must be taken into account before laying an external water supply line, at the planning stage of a future engineering project.
Due to their poor resistance to temperature extremes and their high performance, PVC pipes are not usually used in heating systems. The operating temperature limit of such collectors is 70-75⁰С. With such indicators, the material becomes softer, its elasticity increases. As a result, deformation of products may occur, which is fraught with breakdown and the need to replace the heating main.
Even if you decide to use PVC pipes in the heating system, you should avoid large fluctuations in temperature conditions. When implementing a heating project with the help of such collectors, it will also be necessary to place their fasteners much closer to each other in order to avoid deflections.
Most often, polypropylene materials are used to supply hot water in heating networks. Their service life in the field of heat supply significantly exceeds the indicators of polyvinyl chloride. They can supply substances with temperatures up to + 90⁰С, while even if there is a sharp jump to + 110⁰С, the collectors and the pipeline will not suffer. An ideal option for arranging thermal systems is polypropylene materials with PN25 marking, indicating the reinforced structure of the blanks.
What type of PVC is used for water lines?
The durability of the water supply system largely depends on the quality of the materials used during its installation. Today, polymer products are widely used. Polyvinyl chloride is a material composed of carbon, hydrogen, and chlorine. It is possible to influence the properties of finished products by introducing impurities into them during their manufacture. Polyvinyl chloride is not toxic and allows you to transport all kinds of liquids, acids (sulfuric, phosphoric, hydrochloric), and oils.
Characteristics of PVC pipes
Pipes are divided into polyvinyl chloride (PVC) for cold water supply systems and chlorinated polyvinyl chloride (CPVC) products for hot water supply.
Important! The use of special stabilizers increases the impact resistance and frost resistance of pipes, preserves the integrity of the structure under mechanical stress.
For water pipes, pressure products are usually used. One of the most important properties of PVC water pipes is the ability to work with high pressure in the network.
According to the classification, the pipes are divided into 4 markings:
- standard size: large, medium, small;
- bending radius: rigid, flexible, very flexible;
- type of styling: external, internal;
- working pressure: pressure, non-pressure, for rarefied media.
Installation of external water supply systems is carried out by pipes with a diameter of 9-63 cm at an operating pressure of 6-10 bar. In free-flow water pipelines, PVC products with a diameter of 11-63 cm are often used at a pressure of no more than 0.16 MPa.
The standard pipe length is 1; 2; 3 and 6 m, diameters are very different – from 1.2 to 63 cm. If necessary, they are cut with special scissors into the required lengths and trimmed.
When choosing pipes, it is necessary to pay attention to the wall thickness, which should be the same along the entire circumference of the section, the absence of roughness and sagging.
Technical indicators of PVC products
The choice of pipes is carried out by marking, which is applied to the surface of the pipe and reflects its main parameters. According to international standards, PVC pipes for water supply are equipped with a barcode indicating the main characteristics:
- SDR is the ratio of the outer diameter to the wall thickness;
- pipe wall thickness;
- outside diameter;
- conditional pass;
- nominal pressure;
- ring stiffness;
- maximum pipeline pressure.
Numerous parameters and requirements for such products are given in the regulatory documents for the manufacture of pipes. For PVC pipes, the main ones are several indicators, which are presented in the table.
|life time||50 years|
|density||1.4 g / cm³|
|thermal conductivity||0.15-0.25 W / (m * ° C)|
|calculated linear expansion coefficient||0.07 mm / (m * ° C)|
|change in pipe length after heating||no more than 5%|
|tensile yield strength of pipes d> 1.2 cm||not less than 49 MPa|
|elongation at break of pipes d> 1.2 cm||not less than 25%|
|opacity||no more than 0.2%|
PVC water pipes have a safety margin of 1.25 units for cold water and 1.75 units for hot water. For external water systems, pipes with SDR 41-17 are most often used for pressures of 16-6 bar. They are gray in color and differ from sewer pipes in the type of socket.
Main advantages and disadvantages
PVC pressure pipes are lightweight and are sold at a relatively low cost. They have a flare with an O-ring, which allows you to obtain a tight connection without the use of an additional seal. Installation does not require welding machines and sophisticated tools. Due to its simplicity, installation can be done by hand.
Since the pressure pipes are resistant to decay and corrosion, the water flowing through them is clean. Products made of polyvinyl chloride are characterized by reduced flammability. The inner surface of PVC pipes is always free and clean since there is no accumulation and deposition of salts on their walls. This property increases the service life of the products.
Drinking water can be transported through PVC pipes. A wide variety of elements allows, if necessary, to arrange a curved water supply line. Bacteria do not grow inside these pipes. There are 12 times fewer bacteria on 1 cm2 of PVC pipe area than on a similar section of a polyethylene pipe, and 9 times less than on a polypropylene pipe. PVC pressure pipes are UV resistant, which makes them suitable for outdoor plumbing.
Of the disadvantages of PVC pipes, one can single out the impossibility of using them in the hot water supply or heating systems. The maximum short-term heating temperature for them is 65 °, and the optimal one is 45 ° C. Pipes require good insulation at negative temperatures (less than -10 ° C).
Important! PVC pipes for water supply must not be burned, since chlorine is released during combustion.
Difficulties are possible when joining PVC pipes with products from other materials.
PVC pipe connection
There are three ways of joining PVC pressure pipes for water supply:
- using couplings ;
- into the bell;
- flange connection;
- cold welding.
To connect PVC pipes with the glue method, you must first check the elements for their compatibility. To do this, simply insert the pipe into the appropriate fitting. Further, the required length of the product is cut off with construction scissors or a hacksaw for metal. The pipe end is cleaned with a file or a chamfering knife. After blowing and degreasing, glue is applied to the surfaces to be joined.
The pipe is inserted into the fitting and turned 1/4 turn to distribute the adhesive evenly. The connection is fixed for 20-30 seconds, and the docking process itself should not exceed 1 minute in time. After that, the remnants of the glue are removed. When using pipes with a diameter of more than 50 mm, tightening devices are additionally used.
Couplings are used to connect pipes with a diameter of 5-11 cm. The product of the required size is cut off, attached to the sleeve and the markings are applied to it. The inner surface of the coupling and pipe is lubricated with glue and they are fixed according to the marks. The pipe must go 2/3 into the corresponding fitting.
The socket connection method is simple and fast. The joints are lubricated with a silicone compound and connected by insertion into the socket up to the pipe mark. It is important to maintain the alignment of the elements.
Installation of the plumbing system is carried out in several stages. First, it is necessary to draw up a clear and detailed diagram of the future network, indicating the points of placement of devices and the necessary elements with their size and number. It is important already at the planning stage to have a good idea of how the pressure pipes will run.
Further, the system is disconnected from the water supply and the old pipes are dismantled. To install PVC pipes, you will need scissors for cutting them, a cleaner, glue, special brushes for applying glue, and cleaning the surfaces glued together.
Large diameter PVC pressure pipes are cut with a roller cutter. Care must be taken to maintain the right angle of the cut relative to the axis of the product. The ends should be finished with a chamfering knife or field.
Before gluing the pipeline parts, the parts to be joined are lubricated with a cleaner. The process of connecting pipes is based on the dissolution of the upper layers of the surfaces to be joined with glue. Materials penetrate into each other’s structure, forming a monolithic joint, characterized by tightness and strength.
Note! If the connection is made correctly, an even layer of glue will appear at the junction of the fitting and the pipe, which can be wiped off with a rag.
It is better to use the glue recommended by the manufacturer.
Characteristics of fittings
Fittings for pressure water supply systems have a wide range of models and sizes. Based on the characteristics of the pipeline, the corresponding types of parts are determined that perform certain functions.
The coupling is used for straight sections of PVC pressure pipes. It is a double socket and is used for joining pipes and nozzles that have smooth ends. The repair sliding sleeve has grooves for the rubber O-ring on both sides. Due to its structure, it slides along the pipe from the outside and allows repair work in hard-to-reach places.
Tees are used to connect PVC pipes with products made of other materials or to branch the pipeline. For use in pressure networks, they are equipped with three-sided sockets.
In some areas of the water supply systems, nozzles are installed. They join PVC pipes with valves or pipe systems made of other materials. If the diameter of the pipes changes, then transition pipes are installed.
If the direction of the water flow has deviated or the network configuration is changed, elbows or bends are used. They have one end smooth, and the other with a bell. There is also the possibility of inserting PVC pipes into the pipeline. Saddle bends are used for this. The tapping is carried out using a conical or cylindrical threaded connection. The ends of the pipes can be closed with blind PVC flanges.
Thus, PVC pipes are the most profitable and suitable choice for the installation of water supply systems. Their quality, reliability, and a variety of shapes allow you to lay a water supply system with long service life.