Ruskon Betoni Etelä Oy
Extension rings from Hollola concrete plant
Extension rings are used to adjust the final cover level of a manhole. They are installed on top of a cone-ring shoulder or manhole cover to achieve the required cover elevation.
Several sizes are available to suit different installation requirements. Raising rings can also be supplied with a bevelled profile to match the slope of the road surface, ensuring correct alignment of the cover with the finished grade.
Ruskon Betoni Etelä Oy
Extension rings from the Kokkola concrete product plant
Extension rings with groove joints are designed for raising manholes and/or adjusting them to the final ground level. The extension rings fit directly on top of our DN600 manhole rings.
Napapiirin Betoni Oy
Extension rings from Napapiirin Betoni
Raising rings are used to adjust the manhole cover level to the required final elevation.
The raising rings manufactured at the Rovaniemi plant have a DN600 diameter and are available in heights of 50, 100, 150, and 200 mm. The rings feature a flat-edge design without a rebate, making them a simple and practical solution for manhole height adjustment.