Flexibility
The flexibility of polyethylene pipe allows it to be curved over, under, and around obstacles as well as make elevation and directional changes. In some instances, the pipe's flexibility may remarkably eliminate the usage of fittings and greatly reduce installation costs.
CHUANGRONG PE pipe can be bent to a minimum radius between 20 to 40 times the diameter of pipe,which mainly depends on the SDR of the certain pipe.
Table :Minimum allowable bend radius of HDPE pipe at 23℃
| SDR of the pipe | Mininumallowable bend radfus,Rmin |
| 6 7.4 | Rmin >20×dn Rmin>20×dn |
| 9 | Rmin>20×dn* |
| 11 | Rmin>25×dn* |
| 13.6 Rmin>25×dn* | |
| 17 | Rmin>27×dn* |
| 21 | Rmin>28×dn* |
| 26 | Rmin >35×dn* |
| 33 | Rmin>40×dn* |
*dn:is the nominal outside diameter,in millimeters
Light Weight
Life Expectancy
The density of PE material is only 1/7 of that of steel. The weight of PE pipe is much less than that of concrete cast iron, or steel pipe.The PE piping system is easy to handle and install,and reduced man power and equipment requirements may result in installation savings.
The hydrostatic design basis for CHUANGRONG pipe is based on extensive hydrostatic testing data evaluated by standardized industry methods.The long-term behavior for internal pressure resistances provided by the hydrostatic strength curve based on the EN ISO 15494 standard (see section X). The application limits for pipes and fittings, as shown in the pressure-temperature diagram, can be derived from these curves, which show that the pipe has a life expectancy of approximately 50 years when transporting water at 20℃. Internal and external environmental conditions may alter the expected life or change the recommended design basis for a given application.
Weathering Resistance
Thermal Properties
Weathering of plastics occurs by a process of surface degradation, or oxidation, due to a combined effect of ultra violet radiation, increased temperature, and moisure when pipes are stored in exposed locations. Black polyethlence pipe,containing 2 to 2.5%finely divided carbon black,can be safely stored outside in most climates for many years without damage from ultra-violet exposure.Carbon black is the most effective single additive to enhance the weathering characteristics of plastic materials. Other colors such as white, blue, yellow or lilac do not possess the same stability as the black pigmented systems and the period of exposure should be limited to one year for optimum retention of properties.With these color systems the external surface oxidation layers develop at a faster rate than those in carbon black
stabilized PE pipes.These colored pipes are not recommended for above ground applications.
Polyethylene pipes can be used at temperatures ranging from-50°C to +60°C. At higher temperatures, the tensile strength and stiffness of the material are reduced Therefore, please consult the pressure-temperature diagram. For temperatures below O°Cit must be ensured that the medium does not freeze, to avoid consequently damage to the piping system.
Like all thermoplastics, PE shows a higher thethermal expansion the metal. Our PE has a coefficent of linear thermal expansion of 0.15 to 0.20mm/m K, which is 1.5 times greater than that of e.g . PVC . As this is taken into account during the planning of the installation there should be no problems in this regard.
The thermal conductivity is 0.38 W/m K.Because of the resulting insulation properties, a PE piping system is notably more economical in comparison to a system made of a material like copper.
Combustion Behavior
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Polyethylene belongs to the flammable plastics.The oxygen index amounts to 17%.(Materials that burn with less than 21%of oxygen in the air are considered to be flammable).
PE drips and coninues to burn without soot after removing the flame. Basically, toxic sustances are released by all burning processes. Carbon monoxide is generally the combustion product most dangerous to humans. When PE burns , primarily carbon dioxide, carbon monoxide and water ar formed.
The self-ignition temperature is 350℃ .
Suitable fire-fighting agents are water,foam,carbon dioxide or powder.
Biological Resistance
PE pipes may be subject to damage from biological sources such as ants or rodents. The resistance to attack is determined by the hardness of the PE used, the geometry of the PE surfaces, and the conditions of the installation. In small diameter pipes, the thin wall sections may be damaged by termites in extreme cases. However damage often ascribed to termite attack in PE has subsequently been found to be due to other sources of mechanical damage.
PE pipe systems are generally unaffected by biological organisms in both land, and marine applications, and the paraffinic nature of the PE pipe sufaces retards the build up of marine grothes in service.
Electrical Properties
Because of the low water absorption of PE, its electrical properties are hardly affected by continuous water contact.Since PE is a non-polar hydrocarbon polymer, it is an outstanding insulator.These properties, however, can be worsened considerably as a result of pollution, effects of oxidizing media or weathering. The specific volume resistance is>1017 Ωcm; the dielectric strength is 220 kV/mm.
Because of the possible development of electrostic charges, caution is recommended when using PE in applications where the danger of fires or explosion is geven.
CHUANGRONG is a share industry and trade integrated company, established in 2005 which focused on the production of HDPE Pipes, Fittings & Valves, PPR Pipes, Fittings & Valves, PP compression fittings & Valves, and sale of Plastic Pipe Welding machines, Pipe Tools, Pipe Repair Clamp and so on.
If you need more details, please contact us +86-28-84319855, chuangrong@cdchuangrong.com, www.cdchuangrong.com
Post time: Nov-14-2024
