Pipe lining is an implementation technique where multiple instructions are overlapped in execution. The computer pipeline divided in stages . Each stage completes a part of an instruction in parallel. The stages are connected one to the next to form a pipe - instructions enter at one end, progress through the stages, and exit at the other end.
Pipe lining does not decrease the time for individual instruction execution. Instead, it increases instruction throughput. The throughput of the instruction pipeline is determined by how often an instruction exits the pipeline.
The process involves very little disturbance caused by open trench excavation. A constant-tension winch guides the pipe bursting tool through the host pipe. The old pipe is burst underground and a new continuous pipe is pulled through.
If desired the new pipe can actually be of a slightly higher diameter than the old pipe. The rear expander displaces host pipe fragments into the surrounding soil, while the tool pulls in the new polyethylene pipe.