When creating or repairing plumbing communications, one inevitably has to delve into the issue of pipe characteristics. Indeed, depending on the existing conditions, it is necessary to purchase one or another variety of such products. The diameters of water pipes are one of their most important characteristics. Therefore, much attention is paid to this issue.
There are several main varieties of water pipes. Depending on the group to which each product belongs, there are certain sizes. What are the diameters, how to select them, should be considered before buying and installing the system.
General characteristics
For the arrangement of the water supply system inside buildings, metal, plastic and combined pipes are used. Each variety has its own measure of measurement. Water pipes can be measured in inches or millimeters. The choice of calculation depends on the characteristics of the product.
To fix the dimensions of the water pipe,3 main indicators are used. These include outer diameter, inner diameter, and wall thickness.
In the last century, when only steel pipes stood in the apartments of ordinary citizens, a peculiar system was invented for calculating the size of communications. The internal diameters of water pipes (in mm it is 12.7) could be, for example, half an inch. But at the same time, the outer size and thread reached as much as 21 mm. Therefore, for thread marking, it was indicated that it was ½ inch.
Steel and copper pipes
The diameter of steel water pipes is indicated in the marking by the size outside, as well as the wall thickness. For example, a 60x3 product is communications that have an outer section of about 60 mm and a wall thickness of 3 mm. In this case, the internal section will be equal to 54 mm. There is also a simple metric system. Its marking, for example M14, indicates that the pipe has an outer diameter of 14 mm.
But for copper products, the inch system of measurement is used. Moreover, the marking is made taking into account the outer diameter. At the same time, there is a certain correspondence between the dimensions of copper pipes and the metric system. For example, 1 inch equals 25.4 mm.
If in the course of work it is necessary to connect a steel pipe with plastic varieties, special couplings are used. Difficulties may arise here. To choose their size, you need to pay attention to the marking indicator of the steel pipe.
Plastic pipes
Several different approaches to labeling have plastic water pipes. Diameters, whose GOST number is 18599-2001, have a large range. Plumbing communications with a cross section from 20 to 1200 mm are on sale. Most often, the choice falls on products such as PE 80 or 100.
PE 80 pipes are designed for cold water supply (0-40 °C). They are painted black with a longitudinal stripe of blue. The inner diameter of the most commonly used communications can be from 16 to 110 mm. Their working pressure, depending on the group, is from 0.32 to 2 MPa.
PE 100 is a pressure pipe. It is made by extrusion. This variety is used in outdoor cold water systems.
Polyethylene pipes go on sale with a marking that indicates the type of product, its purpose, wall thickness and diameter, as well as the GOST marking, according to which this product was created.
PP and PVC pipes
The plastic water pipe is commercially available with wall thickness markings. Manufacturers also indicate its outer diameter. This is one of the new types of water communications. Therefore, they are made according to standards (eg 4200/DIN or 2458 ISO, etc.).
On such pipes there must be a trademark and certification of the material. There are several types of polypropylene communications, depending on the nominal pressure.
The outer size of the presented pipe varieties can be specified both in inches and in metric values. The choice of system depends on the manufacturer.
PVC pipes are designated in the same way as polypropylene varieties. For both types of products, the dimensions do not match the usual values of the metric system.
Conversion of inches to millimeters
A water pipe whose outer diameter is indicated in inches can be converted to millimeters. The procedure should be considered with an example. Let's say a pipe with a diameter of 1 inch is purchased. Its outer diameter when measured with a ruler is about 25.4 mm.
But for the selection of fittings, you need to know the indicator for the thread. If we take into account the technical parameters of a cylindrical thread for pipes, then the outer diameter of this indicator will be 33.2 mm. This is due to the peculiarities of production. The thread is cut from the outside of the communications. Therefore, its relation to the inner diameter is rather conditional. For calculations, double the wall thickness is added to the value of 25.4 mm.
Choice of diameter
Diameters of water pipes are an important characteristic. This is due to the bandwidth of communications. It is the diameter that determines how much water will pass through the system per unit time. The greater the pressure drop in it, the greater the fluid flow rate.
Special techniques to calculate the bandwidth of communications. Special tables are also used. ATdue to the fact that such a calculation is rather complicated, it is almost never used when equipping the system indoors.
Usually, professional repairmen and home craftsmen are guided by simplification. When creating plumbing inside the apartment, they acquire ½ inch pipes. When arranging a riser, communications with a cross section of ¾ or 1 inch are required.
Material dependent diameter
As mentioned above, a plastic water pipe can be joined with steel communications. To find the right fittings, you need to purchase their standard varieties. In their manufacture, the dimensions of the pipes are taken into account depending on the material. Therefore, there should be no difficulties in this process.
But when changing copper, aluminum pipes, you will have to delve into the issue of their regulations. The size of such products is indicated in the metric system. Moreover, when joining them with plastic varieties, one should take into account both the inner and outer diameters, as well as their actual size in millimeters.
So, for internal wiring, you can purchase products with a diameter of 10 and 15 mm, and for a riser - 20 and 25 mm. It should also be noted that a plastic pipe with a cross section of half an inch can be characterized by an internal size of 11-13 mm.
Familiarizing yourself with such a characteristic as the diameters of water pipes, you can choose the right products for the communication system.
