Nodular cast iron manhole cover grate is welded by flat steel and twisted square steel or flat steel and flat steel. Here are their points
1. It has the advantages of beautiful appearance, good drainage, high strength, multiple specifications and low cost.
2. With the development of science and technology, a new kind of ductile iron manhole cover grate is formed by using resin or plastic with steel bars as reinforcement and inorganic fillers, which has the advantage of being light.
3. Anti-theft.
4. Good bearing capacity.
5. Good drainage: The leaking area is 83.3%.
Ductile iron manhole cover grate installation three points of attention:
①: In order to ensure the fundamental strength requirements, the cement foundation must be placed before the rainwater grate is installed, and then the rainwater grate is installed.
②: After installing the rainwater grate, install fastening screws around it, and pour cement mortar at the bottom of the frame to prevent the rainwater grate from falling off due to various reasons.
③: Eccentric rainwater grate of any shape can be installed according to the actual situation to meet the actual requirements. The brick masonry of the manhole cover should be determined according to the size of the manhole cover designed by the design institute to determine its inner diameter or length X width and radius (if according to the actual sample Construction is good), it can also be implemented according to standards. And cast a 40cm-wide concrete protection ring around the manhole cover (if it is a cement pavement, you can also cast a 20cm-wide concrete protection ring and reinforce it with steel bars). The maintenance period should be more than 10 days.
2. When installing a well cover on an asphalt pavement, care must be taken to avoid direct rolling of the well base by the construction machinery. When the pavement is cast as a whole, a hole slightly larger than the well base should be reserved on the road surface and placed after the asphalt is paved.
3. In order to maintain the beautiful appearance of the cover, the surface pattern and writing should be clear. When the asphalt pavement is constructed, the cover should be covered with thin iron sheet or wood. The black cover can also be painted with waste oil to prevent the asphalt from spraying on the cover. In the construction of cement pavement, the manhole cover should be covered with plastic film to prevent the cement mortar from contaminating the surface of the manhole cover and damage the surface pattern and writing. You can also clean the surface of the manhole cover with water when the construction is completed that day.
Four. After the concrete is poured on the well base or the asphalt is laid, the well cover should be opened and cleaned in time to avoid mortar or asphalt pouring the inspection well cover and the base into a body, so as not to affect the opening in the future. The above items must be paid attention to by the construction unit.
1. Before installation, the foundation of the manhole cover should be neat and firm, and the inner diameter, length and width should be determined according to the size of the manhole cover.
2. When installing composite manhole covers on cement roads, pay attention to the wellhead masonry to be poured with concrete, and to build a concrete protection ring on the periphery for maintenance for about 10 days.
3. When installing composite manhole covers on asphalt pavement, attention should be paid to avoiding the direct rolling of the manhole cover and well seat by the construction machinery to avoid damage.
4. In order to maintain the beauty of the manhole cover and the clarity of the writing and pattern, be careful not to stain the manhole cover by pouring asphalt and cement on the road surface.
5. Wellhead, reinforced well circle and well frame must be consistent.
6. Before installing the manhole cover, carefully check whether the type, size and structure of the manhole cover meet the design standards, and check for damage, cracks, etc.
7. The well frame, well cover and accessories must be installed firmly, stably and in the correct position. It should be intact and undamaged.
8. Commercial concrete must be used for pouring; when the concrete curing time is insufficient, early-strength, quick-setting concrete should be used; the concrete must be vibrated and compacted and closely integrated with the road structure.
9. Do not disturb the surrounding pavement structure during excavation and removal of the surface layer and base material at the wellhead.
10. Before pouring the well circle, the well frame should be cushioned according to the measured elevation; the wellhead internal mold must use a shaped template.
11 The number of embedded bolts shall not be less than 6; if the embedded bolts cannot be installed, other methods must be used to strengthen the well frame, such as expansion bolts or steel mesh.
