Pipes are the key element in the water supply and heating system. It depends on them how high-quality the heating will be and how durable the water supply system will be. That is why today cast iron pipes are no longer in such demand as before, because they are heavy, difficult to install and prone to corrosion. A newer option, metal-plastic pipes, is devoid of all these disadvantages, but during their installation a huge number of joints are formed, which can negatively affect the performance of the heating or water supply system. The most modern and reliable option at the moment is polypropylene pipes, but in order to get the maximum benefit from their use, you need to choose the appropriate option.
Polypropylene pipes are confidently replacing metal pipes from the market and are becoming one of the most popular materials today for arranging a heating or heat supply system. All this is due to the combination of their positive qualities. So, they are not afraid of corrosion, they can easily withstand high pressure, are easy to install, and are lightweight. In addition, they are durable, practically do not wear out, and due to their smooth surface they are not able to accumulate scale. Also, such pipes can withstand negative temperatures, and at the same time are relatively inexpensive, which provided the material with the widest popularity among buyers with completely different budgets. When choosing pipes, it is worth starting from future operating conditions, stopping at those that are most suitable for a particular room. It is also worth noting that it is better to buy pipes along with everything necessary from reliable manufacturers and in proven places: a vivid example is the products presented by AquaLand on http://www.akvalend.ua/.
And now let’s dwell on what polypropylene pipes are, and which ones are best suited to specific conditions.
Types of polypropylene pipes
The properties of pipes directly depend on the structure of the material:
PPH (polypropylene homopolymer) is a solid material, the disadvantage of which is the inability to withstand low temperatures. That is why such pipes are most often used when arranging industrial pipelines for supplying cold water, or when organizing ventilation ducts;
РРВ (block copolymer) is an excellent wear-resistant material, which contains up to 30% polyethylene. It is he who gives the finished products the ability to withstand low temperatures, as well as the necessary flexibility. Due to all these advantages, these pipes are often used not only for supplying cold water, but also for transporting aggressive substances. In addition, this type of pipe is used in the arrangement of internal sewerage and floor heating. Impact-resistant pipes and fittings are also made of this material, which once again confirms their excellent performance properties;
PPR, PPRC (propylene and ethylene copolymer). Such pipes are widely used in the arrangement of cold and hot water supply systems, heating, incl. and floor-standing, but it should be borne in mind that the temperature of the coolant should not exceed 70 ° C;
PPs (special propylene) is the most popular material today, which should be chosen for arranging a reliable heating and heating system at home. Such pipes have incredible operational properties: they withstand high pressure, low temperatures, and the coolant can be supplied to them with temperatures up to 95 ° C, and at the same time you can be absolutely sure that nothing will happen to the pipe material.
What are the types of reinforced pipes?
With all its advantages, propylene pipes have one drawback – when the temperature rises, they are able to expand, lengthen. To mitigate this feature, manufacturers have long got used to reinforcing pipes. If you need to purchase a product for arranging hot heat supply or heating, then reinforcement becomes a prerequisite. It is also worth considering that the reinforcing layer is made of different materials:
aluminum foil, which is located in the pipe walls, gives the product the necessary strength, but at the same time complicates the installation;
a layer of polyethylene that is applied to the inner walls of the pipe. This type of pipes is actually metal-plastic pipes, the outer layer of which is made of polypropylene. The main advantage of this solution is that the pipes can withstand higher temperatures, but it does not do without a number of disadvantages. Again, these are some difficulties during installation, as well as the multi-layer of the product, which cannot but affect the reliability and durability, because different layers are connected with glue;
- fiberglass reinforcement is considered the most reliable solution today. Such products have a monolithic structure, have high rigidity, and hardly change when exposed to high temperatures. In addition, during installation, such products are simpler, since there is no need to perform special cleaning before welding, as is the case with the two previous types of pipes.
The working pressure for which specific pipes are designed is another important parameter that must be taken into account when choosing. It is worth starting from what exactly these pipes are needed for: hot or cold water supply, or maybe a heating system.
So, the products should be marked accordingly: after the letters PN, there is a number corresponding to the value of the fluid pressure for which specific pipes are designed. So, for example, PN10 pipes withstand a pressure of 1 MPa, PN20 – 2 MPa, PN25 – 2.5 MPa, etc. Depending on a number of other characteristics of pipes with different working pressures in each specific case, you need to choose the most suitable product:
PN10 pipes are one of the cheapest options, they are distinguished by a thin wall and can withstand temperatures up to 20 ° C, therefore they are recommended for use only in a cold water supply system;
PN 16 can withstand temperatures up to 60 ° C, therefore they can be used in both cold and hot water supply;
PN20 pipes perfectly tolerate temperatures up to 80 ° C, therefore they are excellent for hot water supply;
pipes PN25 with reinforcement are used in the heating system, but can also be used for water supply.
Pipe diameter is another parameter that needs careful consideration. So, before designing a water supply or heating system, it is better to calculate what pipe diameter is needed. For large private houses or for apartment buildings, it is better to use a special calculation, and for a small house, you can take pipes with a diameter of 20 mm (for heating) or even 16 mm (for water supply). If the pipe diameter is larger than necessary, there will be little harm from this, but it is difficult to call such a solution an economical solution. If too small a section is chosen, then there will be problems with the pressure.
In the modern construction market, pipes with a diameter of 16 mm and up to 1200 mm are presented, but such huge products are used more often in industry and production. For a home heating system, pipes with a diameter of 16-32 mm are quite suitable, for sewage – from 40 to 110 mm. We are talking about the inner diameter of the pipes, since the outer diameter has nothing to do with it and can only indicate the thickness of the walls, which determines the rigidity of a particular product.
There is a formula that allows a rough calculation of the required diameter of a polypropylene pipe for water supply, and it looks like this:
, where Qtot is the peak water flow rate, v is the speed of water movement (1.5-2 m / s for thick pipes and 0.7-1.2 m / s for thin ones).
When calculating, it is better to use the maximum speed values for this type of pipe, since the smooth surface of polypropylene practically does not resist the movement of water.
Substituting specific values, you can deduce the value of the diameter of the pipes required to organize the water supply in the house. More accurate hydraulic calculations will be needed to organize water supply for an apartment building, but even here there are already time-tested solutions: pipes with a diameter of 25 mm are used for five-story buildings, and 32-mm pipes for nine-story buildings. Pipes of larger diameter are used to supply water to apartment buildings, but polypropylene is not applicable for heating mains, since the water temperature on the supply pipeline is often so high that even reinforced reliable products cannot cope with such an impact.
Naturally, it is better not to take pipes with a diameter less than necessary, otherwise there is a risk during rush hours to be left with poor water pressure or even without it. But, on the other hand, there is a temptation to take a pipe with a diameter much larger than necessary, because in this case it is unnecessary to count anything, check, etc. Such a rash decision will not only require more money to buy products, but also will not allow saving in the future.
To find out the inner diameter of a polypropylene pipe, if it is not indicated on the package, you can use the ratio of the outer and inner diameters. So, with an outer diameter of 16 mm, the inner diameter will be 10 mm, with 20 mm – 15, with 63 mm – 50, with 125 mm – 100, etc.
When organizing a heating or water supply system for an apartment or a small house, accurate calculations in most cases are not needed, since there are not so many water intake points. Most often, pipes of 20 mm are used when arranging heating and 16 mm when organizing water supply.