Vertical watertight structure used to connect pipelines, to change direction and/or level, to permit access for personnel and/or equipment for inspection and maintenance and to allow aeration and ventilation.
In other terms, it is an opening by which a man may enter or leave a drain, a sewer or other closed structure for inspection, clean and other maintenance operations, fitted with a suitable cover.
Precast Manhole is straight in lower portion and narrows down at the top opening matching with internal diameter of precast manhole cover, using various components. The diameter of precast manhole depends upon the depth of manhole and the inlet and outlet pipe diameter.
Diameter of Precast Manhole Chamber
|S. No.||Depth of Manhole Chamber||Diameter of Manhole Chamber|
|1.||Upto 1.65 Mtr.||1000 MM|
|2.||From 1.65 Mtr. Upto 2.30 Mtr.||1200 MM|
|3.||From 2.30 Mtr. Upto 8 Mtr.||1500 MM|
Components of Precast Manhole Chambers
- SFRC Manhole Cover:SFRC Cover used are as per IS:12592.
- Precast Manhole Riser:
The function of Riser unit is to provide a safe access connection from ground level to the pipeline. Riser section consists of a cylindrical section with an effective length from 150 MM up to 1200 MM.
Riser sections are specified with and without provisions for the installation of Footsteps. Riser section will be made with case-in lifting provisions that makes it easy for the handling and installation.
We are very happy to announce that the Bureau of Indian Standards is working on the draft of Precast Concrete Circular Manhole and which will be soon published by the BIS officially and two of our directors – Mr. Ankur Gupta and Mr. Kushagra Gupta are part of the working committee working on this draft with BIS.
Currently, we are manufacturing Precast Manhole Chambers and Risers as per our drawing. Click here to download the product drawing.