How to read the specifications of PPR water pipes?

The specifications of water pipes are a seemingly simple question, but not everyone can explain it clearly. Because there are different types of pipes in the water pipe industry, and the characteristics of various pipes are different, the meanings of the specifications describing them are also different. The specifications of PPR water pipes are mainly the two parameters of pipe diameter and wall thickness, so let's talk about it in detail.

Pipe diameter specifications

First, let's clarify three concepts: the nominal outer diameter Φ of the pipe, the nominal diameter DN, and the imperial unit.

The nominal outer diameter of the pipe is the outer diameter of the pipe, which is often indicated by lowercase dn, that is, the number after Φ marked on the pipe.

The nominal diameter DN is the average outer diameter of the pipe. It is generally a round integer and a reference value, which is different from the actual pipe size.

The imperial unit refers to the 4-inch pipe, 6-inch pipe and 1-inch pipe that people often say.

The nominal diameter comes from the fact that the wall thickness of the metal pipe is generally thin, so the average diameter of the outer diameter and the inner diameter is almost equal to the outer diameter, that is, DN=Φ. However, for PPR pipes, due to the thick wall thickness, the nominal outer diameter DN is quite different from the actual outer diameter of the water pipe, so they need to be distinguished.

Pipe fitting specifications

The nominal outer diameter dn of PPR pipe fittings is always consistent with the nominal outer diameter of the PPR pipe connected to it, and is often marked on the PPR pipe fittings.

The wall thickness of PPR pipe fittings should not be less than the wall thickness of PPR pipes of the same PPR pipe series S. Most companies have only one series of PPR pipe fittings, the highest standard S2, which is applicable to both hot and cold water.

For threaded pipe fittings, that is, threaded fittings, there are two commonly used thread specifications, 1/2 and 3/4, that is, the difference between 4 points and 6 points, and the corresponding thread nominal diameters are 15mm and 20mm respectively.