Because the PE pipe is more sensitive to the operating temperature, the maximum allowable working pressure mentioned above will also be reduced by the ambient temperature. Generally at -20℃-20℃, we believe that the temperature has no effect on the working pressure of PE pipe; When the ambient temperature is higher than 20 ° C, the maximum working pressure that various types of PE pipes can withstand should be reduced, and the reduction coefficient is shown in Table 1:

Table 1 Reduction coefficient of working temperature to working pressure of pipeline:

The scope of use of polyethylene gas pipe: 

1. P≤0.4MPa

Medium and low pressure gas pipelines should use polyethylene pipes, and sub-high pressure and above pipelines should use steel pipes. According to this provision, polyethylene PE pipe can only be used in the middle and low pressure system in the urban gas transmission and distribution system, and can not be used in the higher pressure stage system, and the higher pressure needs to use steel pipe.

2. Bury the ground

Polyethylene pipes are strictly prohibited for gas pipelines in the interior of buildings and overhead gas pipelines outside buildings. According to this provision, polyethylene PE pipe can only be used for buried ground, not overhead!

Table 2 Performance requirements of polyethylene gas pipe:

Combined with the supply conditions on the market and the opinions of large gas supply units, in line with the economic, safe and applicable selection principles, we recommend the selection of polyethylene PE pipes as follows:

1) Nominal diameter > 110mm, PE100 SDR17 is recommended;

2) Nominal diameter ≤110mm, PE100 SDR11 is recommended;

3) Crossing special sections (or using trenchless technology), PE100 SDR11 should be adopted;

4) Nominal diameter > 250mm, recommended steel pipe.