Sewage pipe lining
Why prefer a rehabilitation liner to a standard ditch when repairing sewers? What are the pros, cons and special methods involved?
Why is the lining of sewer pipes more convenient than replacing an entire pipe?
What should you do when a sewer is defective? Is it necessary to dig up an entire street to replace the pipe? Or can the problem be solved by lining the sewer pipe using a rehabilitation sleeve? Read about the pros and cons of both methods.
When a sewer breaks, it is a truly unpleasant affair, especially if the issue is urgent and requires immediate action.
Two options are available – the standard trench method and trenchless lining of sewer pipes using a rehabilitation sleeve. Let’s take a closer look at both methods:
Standard pipe replacement – a difficult method, yet it may be the only viable option
Repairing or replacing a section of pipe using the standard ‘construction’ method always results in multiple restrictions. A trench means road traffic restrictions, disruption of urban life due to noise and dust, and a general lack of space around the trenches. In addition, this pipe refurbishment method is highly time-consuming.
If circumstances permit, a trenchless repair method such as lining the sewer pipe with a rehabilitation sleeve can be a more cost-effective option.
That said, trenchless methods will not remedy the following:
- Severely structurally compromised piping
- Caved-in pipes
- Excessive pipe spacing
- Incorrect sewer incline
It will, however, tackle other defects.
Sewer pipe lining using a rehabilitation sleeve – the options and the benefits
The principle of sewer lining is that the sleeve is placed within the original sewer, in effect creating an entirely new, self-contained pipe. Lining can cure a number of defects such as:
- groundwater seepage through socket joints
- cracked or collapsed pipe walls
- wastewater seepage into the environment through socket joints
- excessive sewer clogging due to severe mechanical damage of surface
If the defect is not destructive, it can usually be remedied with lining, using a rehabilitation sleeve.
Main benefits of lining sewer pipes with rehabilitation sleeves
- Trenchless sewer repairs do not require building permits or notifications.
- The end result is a completely smooth internal surface of the repaired pipe without any adverse hydraulic alterations.
- The service life of the rehabilitated pipe exceeds 80 years.
- In many cases, a trenchless sewer repair is the most cost-effective method.
- It generates no waste or potential for contaminating the environment.
- Sewer pipe lining can progress at a rate of up to 500 metres a day.
- Rehabilitation of pipes under roads requires no road closures.
Depending on the type of defect, it is possible to choose from the two most commonly used methods for sewer lining:
1. Inverted rehabilitation sleeve cured by polymerisation
When using the inverted sleeve method, a sleeve turned inside out is inserted into the original sewer pipe. The sleeve is pushed inside by a powerful stream of air or water. The sleeve cures by polymerisation, effectively creating a new pipe of hardened plastic. This method allows up to 200 metres of pipe to be rehabilitated in six hours. Further details about this technology can be found using this link>>
2. UV-cured rehabilitation sleeve
Firstly, the rehabilitation sleeve is impregnated with a polyester or vinyl ester resin, following which it is winched into the sewer. UV lamps are then placed inside the sleeve and once it is pressurised, they cure the resin. The result is a new plastic pipe. This technology allows up to 500 metres of sewer pipes to be lined in a day.