(1) When the medium temperature of the PE pipe is higher than 20 ℃, the nominal pressure of the pipe should be calculated according to the ‘technical specification 4.1.1 formula’, which will be greater than the working pressure value of the pipe network;
(2) ‘Technical Regulation 4.2.4’ requires that the distance between the buried polyethylene pipe and the thermal pipe should not be less than 1.5m, and the distance should be calculated according to the condition that the surface temperature of the polyethylene pipe does not exceed 40 ℃;
(3) If a casing is added to the partially exposed pipeline, it is also necessary to verify whether the direct sunlight casing causes the surface temperature of the polyethylene pipe to exceed 40 ° C, otherwise an insulation layer should be added;
(4) The linear expansion coefficient of polyethylene pipe is more than 10 times that of steel pipe and ductile iron pipe, but the elastic modulus of polyethylene pipe is much lower than that of metal pipe, indicating that although the degree of expansion and contraction of polyethylene pipe is relatively high, the Produce
The resulting stress is obviously small, so measures to overcome the axial deformation caused by seasonal temperature differences when laying polyethylene pipes are very important. The fixing method required to control this expansion and contraction is often simple and economical.