Channeling is a condition within a pipe where a low point has developed over time due to internal erosion or corrosion. It can result due to the collection of water or debris in the depressed area, and may also lead to blockages.
Defects in pipelines are often corrected using the latest in trenchless rehabilitation technologies.
Trenchlesspedia Explains Channeling
Channeling is often confused with a similar problem known as a line belly, a sagging of the pipe caused by the settling of soil beneath it. Unlike a line belly, the issue of channeling is not the slope of the pipe. It may take an experienced professional to assess the problem and discern the true cause.
In channeling source of the problem could be erosion, a natural process caused by the constant flow of water, or by corrosion that can occur due to chemical flow through the pipe.
Internal inspection may be done with CCTV, and a tool known as a jetter might be used to clear debris and sediment to get a better look.
Usually, channeling is seen in older cast iron pipes which have a tendency to erode due to the pipe's natural porous surface. Over time, water can dig at the tiny existing dips in the surface, eroding the bottom of the pipe away. A common trenchless rehabilitation method used to fix the issue of channeling is sliplining, where a new, stiff pipe, often made of PVC or HDPE, is inserted into the host pipe, creating a new internal flow system, which is slightly smaller than the original diameter of the host pipe.