Cement Lined Pipe
Cement lined pipe, also called Mild Steel Cement Lined, abbreviated as MSCL, is pipe that is internally coated with a mortar like compound that acts as a barrier between the carbon steel pipe and the process. The lining may be applied by hand, as is the case with pipe fittings, or with a machine. It is commonly used in the transmission of potable water and sewage applications. It is also used when the process fluid may corrode regular carbon steel pipe.
Due to the fragility of the cement lined coating, it is recommended that the pipe is handled as delicately as possible. This includes the use of rubber covered hooks or other equipment that prevents the damage of the lining.
Mortar Thicknesses often vary per manufacturer. Typical mortar thicknesses are:
Cement Lined Pipe Design Considerations
In order to put a branch connection on a cement lined pipe such as a Weld O'let or a Thread O'let, the pipe installer will need to penetrate the pipe and cement. If the cement mortar is not repaired properly or if it becomes damaged, corrosive fluid can become trapped between the cement mortar and the pipe wall which will lead to corrosion. The best way to engineer this out is to utilize bleed rings or reducing tees as much as possible.
Pipe that has been coated with cement has a smaller maximum span than carbon steel that has not. The reason for this is when the pipe is deflecting, the bottom half of the pipe is in compression and the top, in tension. Cement performs excellently in compression but extremely poorly in tension. What will happen is the pipe concrete will either flake off or crack in such a way that corrosive fluid gets between the concrete and pipe wall which eventually lead to premature failure.
Cement Lined Pipe Size
|Nominal Pipe Size (in)||AWWA C205 Mortar Thickness (in)||Maximum Span (ft)|
The Hazen Williams coefficient for new cement lined pipe is typically between 135-150.
Maximum velocity of a fluid of cement lined pipe is 7-9 feet per second.
Some people believe that the concrete mortar has self healing properities if it become cracked or otherwise superficially damaged. This is not true. Concrete linings do not regenerate and cracks do not repair themselves.
Cement Lined Pipe Standards
- ASTM C541 / C541M - Standard Specification for Linings for Asbestos-Cement Pipe
Tags: Pipe Concrete Equations