I. Non-useful for other purpose.
Give a thorough solution for the hazards to passers-by and vehicles due to stealing and subsequent losses.
II. High load
Its loading capacity exceeds various traditional counterparts . Such accidents as breaking and falling of vehicles will never occur.
III. The base and the lid are closely engaged with each other. Free of shaking, jumping, moving and noise. Safe and reliable.
IV. Grinding-resistant, corrosion-resistant and environment-friendly
Service life of over 20 years. Corrosion-resistant , free of pollution and free of maintenance.
V. Good for decoration purpose.
Available in various colors depending on specific demands to beautify the urban environment and improve the level of city.
VI. Light in weight
As heavy as half of the steel manhole lid. Ease of operation. Simple to install and replace, resulting in labor-saving.
The composite material is corrosion resistant, grinding resistant and of high strength and insulation, which can be used to make manhole lid、sewer grate、electric handhole plates characterized by anti-theft, anti-folding, anti-ageing and pressure-resistance. On the basis of market survey, we find the defects of conventional products and come with our newly developed more user-friendly substitutes which are patent protected. Our benefits are as follows:：
1. Every Cross parts of reinforced ribs on the back of manhole lid is triangle-shaped and the joint of reinforced ribs and the lid body is arc-shaped , resulting in the maximizing of loading capacity.
2、In order to avoid the turn-over of manhole lid，a fixing key is available on the manhole seat to prevent the manhole lid against turning over and reduce the possibility of accidents while minimizing the wearing of manhole lid.
3、Cement fixing slots are available on the bottom of manhole lid seat to allow firm installation of manhole lid.
4、The bottom of sewer grate cover comes with arc structure for the maximization of loading capacity.
2、grinding-resistant, corrosion-resistant, environment-friendly
3、High loading capacity
5、slot-fixing structure allows firm mounting.
7、The seat and cover tightly engaged.
8、Light in weight
Examples of Applications
圆弧过渡，arc-structure transition, 强度最大化 maximization of loading capacity, 底座凹槽定位，安装更稳固Slot-fixing at the bottom allows firmer mounting.
Directions for Mounting: You are requested to read this manual in details prior to operating this product.
Proper installation is required to ensure proper and normal operation. The lids of proper type, dimension and application scope shall be securely and elegantly mounted while allowing easy opening by following the below-listed steps:
I、Building of manhole support masonry : The internal diameter or width/height/depth of the support masonry shall be determined depending on the size of manhole.
II. Mounting of manhole seat on the cement road：A 20 cm circular beam made of C25 cement is built at the joint of manhole inlet and the seat prior to being put in the manhole seat. A 40 cm width cement protection ring around the manhole seat is required with a curing date of no less than 12 days.
III. Avoid rolling on the manhole seat directly by construction machinery during the building of cement road. It′s preferred to leave a space slightly bigger than the manhole seat for further installation of manhole seat which shall be carried out after the completing of laying for asphalt road, and after the road has been rolled to solid for concrete road, so as to ensure the solidity and extended service life of manhole seat.
IV. If the manhole seat or manhole lid was installed in advance, some protective measures shall be taken to protect the patterns and characters on the surface of manhole lid. During the construction of asphalt road, you may cover the lid with a thin iron sheet or brush the lid surface with waste machine oil to prevent the asphalt from directly spraying on the surface of manhole lid or the inside of manhole to cover the pattern or characters thereon. If the above measures are unavailable, you may rinse with water till no visible deposit upon the completing of construction.