Views:103 Author:Site Editor Publish Time: 2019-01-14 Origin:Site
The HDPE/PP profiled pipe is more and more widely used in various places. In the process of using HDPE pipes, one important point that can not be ignored is its load-bearing capacity. According to different load-bearing capacity of HDPE pipes and different needs of different places, HDPE pipe is used in different places.
PN refers to the nominal pressure of the HDPE/PP Profiled Pipe. The nominal pressure refers to the working pressure of Winded Profile Pipes water conveying at the secondary temperature (20℃). If the water temperature is between 25℃ and 45℃ degrees Celsius, the working pressure should be corrected according to different temperature drop coefficients.
Nominal pressure PN is a numerically expressed pressure-related symbol, which is a convenient circular integer for reference. All HDPE Spiral Profile Pipe accessories of the same nominal diameter expressed by the same nominal pressure PN value have the same connection size corresponding to the end connection type.
The nominal pressure grades of HDPE pipes according to different external diameters and wall thickness are 0.4 MPa, 0.6 MPa, 0.8 MPa, 1.0 MPa, 1.25 MPa, 1.6 MPa, etc.
Designing pressure and working pressure are also related to nominal pressure. The relationship between them is:
1) Nominal pressure (> design pressure)
2) Design Pressure = 1.5 x Working Pressure
PN is a method of expressing pressure, it is mainly used for pressure indication of HDPE pipes and HDPE pipes fittings, valves and other shell equipment. The definition of PN is very different in GB/T 1048-2005 and the nominal pressure of replaced GB/T 1048-1990 HDPE pipes components. In the technical characteristics of PVC water supply HDPE pipes, PN represents the pressure level of HDPE pipes, DN represents the nominal diameter of HDPE pipes. For example, DN25 PN10 means that the nominal diameter of the HDPE pipes is 25 mm and the pressure level is 1.0 Mpa. There is no direct connection between the two. For example, the water supply HDPE pipes of DN25 has the pressure levels of PN10, PN16 and PN25.
They are all used to express pressure, but the standard is different, so they are called different. In fact, there is a corresponding relationship between Mpa and pound. For example, 150 pounds correspond to 20 kilograms of pressure, CLass150 = PN2.0 flange, also known as flange flange plate or lug. Flanges are the parts that connect pipes to pipes. They are used between the ends of HDPE pipes.
DN25 PN16 steel HDPE pipes, first of all, it is pointed out that DN class of HDPE pipes is often used in welded HDPE pipes, such as welded HDPE pipes DN25. PN16 represents pressure, which is 16 kilograms (1.6 MPa).
Pipeline pn0.8 means the marking of letters and numbers used for reference in relation to the mechanical properties and dimensional characteristics of piping system components at a lift pressure of 0.8 MPa. It consists of the letter PN and the digits followed by dimensionless numbers. Note 1: The number followed by the letter PN does not represent the measured value and should not be used for computational purposes unless otherwise specified in the relevant standards.
PPR HDPE pipes are divided into five series: S5, S4, S3.2, S2.5 and S2.
The corresponding pressure level varies according to the total service coefficient C of the piping system:
When C = 1.25, the nominal pressure is 1.25, 1.6, 2.0, 2.5, 3.2 MPa, respectively;
When C = 1.5, the nominal pressure is 1.0, 1.25, 1.6, 2.0, 2.5 MPa, respectively.
These five series of cold and hot water HDPE pipes can be used, and the piping model DN150-pressure PN1.0 MPa material 304 stainless steel.
After the completion of HDPE pipes construction, pressure test should be carried out. It means that the pressure should reach 0.6 MPa and 0.6 MPa is approximately equal to 6 kg/square centimeter. Generally, the experimental pressure is higher than the working pressure. pn6 is 0.6 MPa.
The meaning of PN is just like what the article said. In short, it is nominal pressure. Understanding PN is very helpful to use HDPE pipes.