Pipeline Construction Process

Pipeline construction projects can span hundreds of miles or can consist of shorter connections linking a distribution center to a storage facitlity. Regardless of the length, the installation must be carefully choreographed to meet construction schedules and seasonal weather conditions.

1. In order to make the right-of-way into a suitable work area, a clearing and grading crew prepares the corridor so the construction equipment can operate safely.
2. Next, the mechanical excavation of a ditch, dug to a specified depth for pipe placement, is done by the ditching crew. Occasionally, rock drilling and blasting is required to break rock in a controlled manner. During the backfill operation, the pipe will be covered with the material excavation from the ditch.
3. After the pipe is delivered to the right-of-way, the contractor strings sections of steel pipe, previously delivered to a central storage location, along the ditch.

4. A bending machine is used to tailor the shape of the pipe to conform to the contours of the terrain or to make changes in the direction of the line.
5. The welding crew begins the process of joining the steel pipe into one continuous pipeline using manual, semiautomatic or automatic welding procedures. Welds are then X-rayed or Ultrasonically inspected to assure pipe joints have been welded in accordance with project specifications.
6. The pipe sections are cleaned and coated and the ditch bottom is cleared of rocks and debris or padded with soft dirt and the pipe is lowered-in to the ditch by sideboom tractors using belts or cradles in a carefully coordinated action.
7. The trench is the backfilled. When soil conditions are not suitable to be directly placed on the pipe, specialized equipment designed to pad the pipe and protect it from sharp rocks and abrasion is utilized.
8. The final phase of the construction involves replacing topsoil, replanting the right-of-way, removing construction material, and restoring the area, as closely as possible to its original pre-construction condition.
9. Completed pipeline must be tested to ensure they will operate at designated pressures without leaking. Pressure tests are usually conducted using water (hydrostatic). The test is carefully monitored and once completed, the pipe is cleaned and dried and ready to be put into service

Presently, there are more than a million miles of gas pipe in the U.S., linking gas supply basins throughout North America to all types of residential, commercial, and industrial markets. Natural gas accounts for about one-quarter of all the energy used in the United States and continues to provide the cleanest, natural fossil fuel. Welded Construction's pipeline projects are an integral part of a environmentally-friendly installation.