Calculation of diameter
The standard pipe diameter designation is as follows:
- Inner diameter is the main characteristic of the pipe and parts for the connection( fittings);
- Outer - small sizes have a range of 5-102 mm, medium - 102-406 mm, large - 406 mm and more.
- Conditional - the nominal size of the internal diameter. Counted in millimeters or rounded in inches;
- Diameter of the nominal pipe;
- Wall thickness.
There is a huge assortment of different pipes on the market, therefore there are normative documents that allow to clearly define the type of each product. For use in everyday life it is very important to know all the features of diameters. For example, when replacing the heating system in a private house, the exact dimensions are necessary so that the system gives uniform heating to the entire room.
The inner diameter of polypropylene pipes can be calculated independently. This skill will allow you to create the right heating system design. It is calculated according to the formula: d = sqrt( (314хQ)( vхdT)), where:
- d - internal size;
- Q - heat flow, kW;
- V - velocity of the coolant, m / s;
- dT - temperature range;
- sqrt is the square root.
Note! If you can not make the calculations yourself or you are not sure of your abilities, contact a specialist.
Features of pipes
Polypropylene pipes are available in sizes of 25, 63, 90 mm and so on. Polypropylene pipes of large diameter, 110 mm, are required in production. Products with a diameter of 63 mm are needed to transport aggressive chemicals. This type of product is indispensable in systems where compressed air is used.
Pipes of the 25th and 63rd sizes are connected to the boiler system, diverging on the floors and serve as a method of connecting individual radiators to the common system. They are also necessary for the installation of warm floors. Polypropylene pipes are manufactured in single-layer and multi-layer. Large sizes are made from a homopolymer, a random copolymer or a block copolymer. Such material offers the following advantages:
- Absolute tightness;
- Long service life, up to 50 years;
- Not exposed to corrosion and atmospheric influences.
Polypropylene is a reliable, durable, yet inexpensive material. For reinforcement, reinforcement is often used. This is done by creating a multi-layer structure, which is possible, thanks to the additional aluminum layer .Often there are five such layers: two layers of polypropylene, between which there is aluminum, connected with plastic by two layers of adhesion( glue).The thickness of the aluminum layer varies in the range 0.1-0.5 mm.
Features of application
The length of polypropylene pipes is four meters, they do not bend when mounted. Between each other, the pipes are connected by special coupling with the use of fittings. The fittings have a metal thread for attaching to devices. The quality of the welded connection makes it possible to successfully use pipes in a compressed air system. Under the influence of temperature, they can significantly change their length. If the product is longer than ten meters, then special flexible temperature compensators are used.
To select the required pipe, you need to know the internal size of the polypropylene pipes in order to calculate the allowable pressure and temperature. Consider the option of changing the linear dimensions due to heat. If this factor is ignored, the pipeline may collapse.
Note! It is important that the fixing of the system is not rigid, and thermal gaps are provided.