... - 50-150 medium, widely used in city central heating field, oil and natural gas business, anti- corrision and thermal pipeline engineer ... very low, about 0.2kg / m2.3.anti-corrosion, good insulation performance, long service life: raw material HDPE, with high mechanical ... good corrosion resistance,effectively prevent the infiltration of water and oil, service life is up to 50 years, three or four ...