| 摘要 |
PURPOSE: A manhole made of color cast iron is provided to prevent entering of water such as rainwater and/or leachate and to freely adjust height of the manhole by adding expansion rubber ring and height control ring to the manhole. CONSTITUTION: The manhole comprises a body portion and a cover portion. The cover portion(30) has a number of anti-sliding sills(34) and two rotational grooves(33), a expansion rubber ring(32) inserted into a groove at lateral side, and two rectangular locking projections(31). The body portion has 'L' shaped grooves at both inner sides of the body to insert and rotate the locking projections(31); another locking grooves for a height control ring at another both inner sides of the body; locking projections corresponding to the locking grooves. The cover portion of the manhole is made by admixing 20-30wt.% PE, 20-30wt.% PP and 5-50wt.% EVA to furnish various colors.
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