| After-sales Service: | Professional Technical Support |
|---|---|
| Warranty: | 12 Months |
| Material: | Iron |
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Audited Supplier Audited by an independent third-party inspection agency
| Model Number | manhole cover,double triangular:AFT-DT-6060D |
| Brand Name | Arfanti |
| origin | China |
| Small Orders | Accepted |
Manhole covers are often made out of cast iron, concrete or a combination the two. This makes them inexpensive, strong, and heavy, usually weighing more than 113 kilograms (249 lb). The weight helps to keep them in place when traffic passes over them, and makes it difficult for unauthorized people without suitable tools to remove them.
Manhole covers may also be made from glass-reinforced plastic or other composite material (especially in Europe, or where cover theft is of concern). Because of law restricting acceptable manual handling weights, Europe has seen a move towards lighter weight composite manhole cover materials, which also have the benefits of greater slip resistance and electrical insulating properties.
Other manhole shapes can be found, usually squares or rectangles. For example, in the United Kingdom nearly all manhole covers are square or rectangular and very occasionally triangular, but almost never circular. Nashua, New Hampshire, is unusual for having triangular manhole covers that point in the direction of the underlying flow. In 2011, the city began gradually phasing out the triangles,[9] which were made by a local foundry, because they were not large enough to meet modern safety standards and a manufacturer for larger triangles could not be found. Some manhole covers in Hamilton, Bermuda, are triangular, and hinged. Some triangular water-main covers also exist in San Francisco
| Item | Manhole cover |
| Material | Ductile iron |
| Color | Black |
| Size | Customer's 3D Drawing |
| Logo | ARFANTI or Customized |
| Load capacity | A15,B125,C250,D400,E600 and F900 |
| Painting | Black bituman/Customer's requirement |
| Certificate | ISO9001,BS-EN124 |
| Tolerance | Machining:+/-0.02mm, finish machining:0.002mm |
The covers usually feature "pick holes", into which a hook handle tool is inserted to lift them. Pick holes can be concealed for a more watertight lid, or can allow light to shine through. A manhole pick or hook is typically used to lift them, though other tools can be used as well, including electromagnets.
Properties
Ductile iron castings are used in almost all major industrial sectors, which require high strength, plasticity, toughness, wear resistance, resistance to severe thermal and mechanical shock, high or low temperature resistance, corrosion resistance and dimensional stability. In order to meet these changes in service conditions, ductile iron is available in many grades, providing a wide range of mechanical and physical properties.
Most ductile iron castings, as specified by the International Organization for Standardization ISO1083, are mainly produced in an unalloyed state. Obviously, this range includes high-strength grades with tensile strength greater than 800 Newtons per millimeter and elongation of 2%. At the other extreme are high-ductility grades with elongation greater than 17% and correspondingly lower strength (minimum 370 Newtons per millimeter). Strength and elongation are not the only basis for the designer to choose a material, but other decisive and important properties include yield strength, elastic modulus, wear and fatigue strength, hardness and impact properties. In addition, corrosion and oxidation resistance and electromagnetic properties may be critical to the designer.
Cast iron manhole covers are generally transported by truck. During transportation, ductile iron manhole covers will inevitably collide and bump with cars and fixed objects, which will damage the surface anti-corrosion layer. When ductile iron is exposed to the air, the outer anti-corrosion layer will be damaged during the unstandardized transportation and hoisting process, and the surface will rust. Or it is inevitable that the internal and external anti-corrosion layers will be damaged by collisions during the hoisting process. Damage caused by improper handling during the construction process. It will also cause damage during the backfilling process.
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