Integral Cast-in-Place Manhole Cover
● Structural Features: The manhole cover is formed by bending or welding a single piece of stainless steel plate. The frame, support surface, and base plate are a single, integral structure with no splicing welds or only a few reinforcing welds. Integral manhole covers offer high rigidity, high dimensional accuracy, and stable and reliable installation. The support surface is typically designed as a flat plane or a grooved annular surface, ensuring good contact with the manhole cover. Integral cast-in-place manhole covers are often used for round manhole covers due to their symmetrical and uniform stress distribution.
● Applications: Suitable for various urban roads, squares, residential areas, and other conventional applications, especially for driveways with a load-bearing capacity of C250 and above. Integral manhole covers are easy to install and have relatively relaxed requirements for foundation flatness, making them the most common type of manhole cover in engineering projects.
● Main Advantages: Strong overall structural integrity, good load-bearing capacity, and less prone to local deformation and loosening; high machining precision, uniform clearance between the manhole cover and the cover, and good sealing; long service life, no stress concentration from splicing welds, and excellent fatigue performance.
Modular Assembled Manhole Cover
● Structural Features: The manhole cover is assembled from multiple independent components, including a frame, support ring, and base plate, connected by bolts or welding. Each component can be manufactured separately and assembled on-site. The elevation and levelness between the support ring and frame can be adjusted using adjusting bolts, offering greater installation tolerance. Modular manhole covers are often used for square or rectangular manhole covers due to their larger size, making overall transportation inconvenient.
● Applications: Suitable for large square manhole covers, non-standard sized manhole covers, and renovation projects with limited installation space. Widely used in landscape projects requiring precise elevation adjustments, facilitating compatibility with paving layers of varying thicknesses.
● Main Advantages: Standardized mass production of components results in short delivery cycles; flexible on-site installation and adjustment accommodates certain foundation deviations; individual component replacement for partial damage leads to cost-effective maintenance; relatively lightweight for easy handling.
Adjustable Modular Manhole Cover
● Structural Features: Based on the modular assembly design, this manhole cover adds a height adjustment function. It consists of a base and an adjusting ring, connected by threads or toothed engagement. Rotating the adjusting ring changes the overall height of the manhole cover, typically ranging from 30mm to 150mm. This type of manhole cover can adapt to road overlay or elevation changes, making it particularly practical in old road reconstruction and pavement maintenance projects.
● Applications: Suitable for old road overlay projects, projects with frequent road elevation adjustments, and areas where future road surface raising is possible. Also suitable for rapid leveling and repair after settlement, without the need to demolish and rebuild the foundation.
● Main Advantages: Convenient and quick elevation adjustment; allows for synchronous raising of the manhole cover and road surface without recasting the foundation; the adjusting mechanism has a locking function, preventing loosening once adjusted; reduces the frequency of manhole cover replacement due to elevation mismatch, saving maintenance costs.
