... from -40°C-90°C, and its service life is over 5-10 years longer than the iron manhole cover. Its performance ... uneasy to break, no percussive noise, rust resistance, long service life. More over, it has no reclamation value, which helps reduce ... resistance 7) Excellent dimension stability 8) Long service life 9) Smooth surface 10) Good flexibility 11) Manufactured using synthetic resin and reinforced ...