What are the requirements for installing manholes? Site details of base fixation, pipe sealing, and sump pit
Release time: October 28, 2026
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The manhole looks like a cylinder with a cover, but there are many installation details. The base, conduit, and water collection pit should be solidly constructed for easy maintenance and minimal water seepage issues.
Well location and foundation pit preparation
After the well location is marked according to the diagram, excavation should be carried out, leaving operating space around the excavation pit size. The base should first lay a cushion layer and level it, review the relative relationship between the elevation of the wellbore base and the process pipes in the tank area, confirm that there is sufficient space for operation and maintenance between the operating well and the valve flange inside the well, and do not realize that the wrench cannot be inserted after installation.
Base fixation and leveling
After the base is in place, level it with a level ruler and fix it with concrete. Once the fixing strength is reached, take over the pipe. Leveling this step cannot be skipped: if the base is crooked, the fit between the wellbore and the manhole cover will be crooked, and rainwater will inevitably seep in through the gaps.
Sealing of pipeline passing through the wellbore wall
The pipeline passing through the wellbore shall be treated with flexible sealing material, and a waterproof sleeve shall be installed outside the pipeline. Sealing needs to be done twice: once filling the joint, once covering the surface, and then backfilling after proper curing. The position where the pipeline passes through the wellbore varies in temperature, and the flexible seal can deform accordingly, while the rigid seal is prone to cracking and water leakage.
Sump and drainage arrangement
Set up a collection pit at the bottom of the well, located in a corner that is convenient for manual water intake, and slope the bottom of the well towards the collection pit. Before the rainy season, pump out the accumulated water in the well and check if there are any seepage points on the well wall. For wells with long-term water accumulation in the collection pit, it is necessary to investigate whether the seal is ineffective or the groundwater level is a problem, and deal with it accordingly.
Manhole cover and concealed inspection
After installing the manhole cover, try opening and closing it several times. The locking mechanism should be flexible and the height difference between the cover and the ground should be smoothly connected. Conduct a comprehensive inspection before concealed backfilling: the valves in the well should be opened and closed normally, the sealing appearance should be intact, the ladder or steps should be firm, and photos should be taken for record before backfilling.
| Check item | Qualified status | Consequences of non-compliance |
|---|---|---|
| Base leveling | Horizontal ruler rechecking meets the standard | Water seepage through the gap of the manhole cover |
| Pipe sealing | Two flexible seals in place | Cracking, water seepage, rework |
| sump pit | Reasonable location and proper slope finding | There is nowhere to go for stagnant water |
Frequently Asked Questions
Should we choose fiberglass or concrete for the wellbore?
According to the design requirements, both materials are suitable for use. Fiberglass is lightweight and easy to install, and the overall integrity of the concrete is good. It depends on the site conditions and budget.
How to deal with wellbore seepage?
First, determine the source of water seepage: if the pipe seal fails, redo the seal, repair the cracks in the well body, and consider strengthening the waterproofing of the outer wall of the well when the groundwater level is high.
How often is the water collection pit cleaned?
Clean up once before and after the rainy season. During regular inspections, if there is an abnormal increase in water accumulation, investigate the cause and also clean up the pit.
What supporting services does WoHong offer?
Luoyang Wohong Petrochemical Equipment Co., Ltd. provides technical support for the matching and installation of gas station manholes, composite pipelines and other equipment. Contact number: 13526990215, email: lixiang@vohon.cn .
