Diameters of polypropylene pipes: correspondence from outer to inner
Polypropylene products differ from other types in their relatively low cost and ease of installation. In addition, pipelines made of this material are not subject to corrosion and deposits, do not conduct electricity, have an aesthetically attractive appearance and leak very rarely. If such a nuisance happens, then it is associated with errors made during installation.
In addition to in-house water pipes and heating systems, polypropylene products are used in ventilation systems, sewage systems, external water supply pipelines, industry and agriculture.
Classification of polypropylene pipes:
- PPH - this is the first type, made from homopolypropylene, has increased strength, is used in systems for cold water, ventilation, in industry;
- PPB - this is the second type, made from a block copolymer, used in ventilation and cold water systems, as well as in warm floors;
- PPR - the third type (the most common), made from a random copolymer, used for cold and hot water, in radiator and floor heating;
- PPs is a special type that allows the temperature of the internal environment up to 95 degrees.
Polypropylene products are also divided into reinforced and non-reinforced. Aluminum foil or fiberglass can be used as reinforcement. The foil may be located near the outer surface or in the middle of the wall.
Diameters of polypropylene pipes: dependence of wall thickness
Before designing a pipeline, you need to know what diameter of polypropylene pipes will be used. There is a complex hydraulic calculation. His goal is to choose such a size for each site in order to save money when buying. The calculation takes into account the working pressure and the structure of the system. A large cross section, of course, does not harm, but it will be very expensive. If the cross section is too small, the pressure will decrease.
What are the diameters of polypropylene pipes? From 16 to 1200 mm! However, for domestic water supply and heating systems, products with a size of 16 to 32 mm are used, for internal sewerage - 40, 50 mm or polypropylene pipes with a diameter of 110 mm. The maximum diameter of polypropylene pipes is relevant when installing external sewer pipelines for very large houses or entire neighborhoods.
When designing an internal cold water system, the choice of size depends on the length of the pipeline and the number of water points. The supply pipe most often has a size of 32 mm; for indoor wiring, the outer diameter of polypropylene pipes is 16 - 20 mm.
No less important is such an indicator as wall thickness. The internal diameters of polypropylene pipes depend on it. The table will help you understand the variety of sizes:
| Outer Diameter (mm) | Wall thickness PN10 (mm) | Wall thickness PN16 (mm) | Wall thickness PN20 (mm) | Wall thickness PN20 with alu. rebar (mm) |
| 16 | - | - | 2.7 | 2.7 |
| 20 | 1.9 | 2.8 | 3.4 | 3.4 |
| 25 | 2.3 | 3.5 | 4.2 | 4.2 |
| 32 | 3.0 | 4.4 | 5.4 | 5.4 |
| 40 | 3.7 | 5.5 | 6.7 | 6.7 |
| 50 | 4.6 | 6.9 | 8.4 | 8.4 |
| 63 | 5.8 | 8.4 | 10.5 | 10.5 |
| 75 | 6.9 | 10.3 | 12.5 | 12.5 |
| 90 | 8.2 | 12.3 | 15.0 | 15.0 |
| 110 | 10.0 | 15.1 | 18.4 | 18.4 |
Calculation of patency: what does it depend on?
When calculating the patency, the outer diameters of polypropylene pipes do not matter. How much water the pipe will let through in a certain unit of time determines the internal section.
Permeability depends on:
- - internal section (with a small section, the resistance of the walls increases, the flow slows down);
- - pressure in the system;
- - the length of the pipeline (the longer it is, the stronger the friction that slows down the flow);
- - material (moving speed is greater with a smooth inner surface);
- - the age of the pipe, that is, the amount of deposits;
- - the number of transitions from one size to another and turns.
For home piping, you can use a simple formula. To determine the optimal diameters of polypropylene pipes, it is necessary to know the water flow rate (Q) and the flow rate:
D = square root of (4-Q-1000/n*v),
v= 0.7-1.2 m/s (up to 32 mm) or 1.5-2 m/s (32 mm or more).
A more accurate calculation is needed in an apartment building. When installing risers in this case, the inner diameter of polypropylene pipes is 32 mm.
Correspondence of diameters of polypropylene pipes:
- - external size 16 mm corresponds to polypropylene pipes with a diameter of 10 mm (internal);
- - external dimension 20 mm corresponds to polypropylene pipe 15 (internal diameter);
- - outer size 63 mm - polypropylene pipes inner diameter 50 mm;
- - external size 125 mm - polypropylene pipes diameter 100 mm (internal).
Polypropylene pipes of large sizes are used for supplying cold water and external sewerage systems (this type of material is never used for supplying hot water). For example, to supply water to a microdistrict, polypropylene materials of 500 mm or more are needed.
Plumbing and heating for a private house or apartment
To create a communications project for a small house or apartment, there is no need for an accurate calculation, since there are few points for drawing water, and the cost of purchasing a small batch depends little on the size. The diameters of polypropylene pipes should be slightly larger than the cross section of the mixer.
Therefore, when installing household communications, polypropylene pipes for heating are simply purchased, with diameters of 20 mm. And the diameter of polypropylene pipes for water supply can even be 16 mm. Polypropylene pipes of large diameter (more than 500 mm) are not needed at all.
