Cement line pipelines can be used for so many applications. These can be used to transport water for drinking purposes and also for wastewater applications. The cement lining was introduced after the iron pipes were used for water transportation as a solution for corrosion and tuberculation. As pH is also increased at the surface by the cement lining, tuberculation is further reduced. This is something that happens when water comes into contact with the bare pipe walls.
Without a lining
The water flow will start to become restricted because the inner diameter of the pipe is reduced because of tuberculation. But when you add a cement lining, it will act as a physical barrier between the minerals dissolved in the water and the pipe wall. Because this physical barrier is there, the minerals will not react or adhere to the pipe wall. Nowadays you can find many companies that supply mild steel cement lined pipe lines for domestic and commercial water transportation services. However, you will not be able to protect the pipe against corrosion that occurs due to bacteria or other microbes. This is usually known as hydrogen sulphide corrosion. This is an issue that will not be solved by a higher wall thickness. However, you can use cement lined pipelines for sewer applications. If you have a gravity system, a cement lining will be more than enough.
You may need a special lining to prevent corrosion when it comes to sewer force mains. But when choosing a type of pipe for a wastewater pipeline, you first need to understand the nature of the system. This can change from station to station. Once you understand the process fully, you will be able to design a layout where you can specify the right linings for the right areas. A fluid has to be within a certain pH range to be considered non septic or septic. And there are certain specifications you will need to maintain such as the angle, speed, score velocity etc. Once all parameters are known, you can use a cement lined iron pipeline so that you can get all the benefits of it. Also, if you have a sewer force main with a pipeline that is always flowing full, you can safely use a cement lined ductile iron pipe.
You may have heard of hydrogen sulphide corrosion
And this is something that can happen in gravity systems. Bacteria can convert sulphates to hydrogen sulphide and this can be further metobolised into sulphuric acid that can corrode the iron pipe. Hydrogen sulphide usually accumulates at high points and you can actually have air release valves at these points. For some additional safety, you can use a speciality lining for these high points. Just because there is the presence of hydrogen sulphide in a pipeline, you don’t need to apply speciality lining for the entire pipeline. You can determine how far this has to be done and keep the rest of the cement lined pipeline without the speciality lining. This will bring down costs and still keep performance of the pipeline at a high level.