Construction Process

Clearing, Grade and Environmental:

This crew is responsible for removing trees, boulders and debris from the construction right-of-way and preparing a level-working surface for the heavy construction equipment that follows.

The crew installs silt fence along the edges of streams, wetlands and parts of the edge of the right of way to prevent erosion of disturbed soil. Trees inside the right-of-way are cut down where permitted, and the contractor removes or stacks the timber along the side of the right-of-way depending what we are required to do.

Horizontal Directional Drilling Method:

Here on this Project we will be using Horizontal Directional Drill in 11 locations. In these locations, there will be very little disturbed on ground level. As you can see, the area in between the entry and exit points there is no disturbance to the natural contour and features.

Trenching (Conventional Pipe Lay in some areas)

The trenching crew typically uses a backhoe or (Excavator) to dig the pipe trench. If the crew finds large quantities of solid rock during the trenching operation, it uses special equipment or explosives to remove the rock. The crew uses explosives carefully, in accordance with state and federal guidelines, to ensure a safe and controlled blast. Prior to any blasting property owners in the blast zone will be notified.

Stringing of the Pipe

The pipe will be brought the construction site prior to trenching operations on this particular project. This will eliminate the trench being open for long periods of time. The pipe is placed on wooden timbers or (skids) and a pad placed between the pipe and skid to ensure coating integrity.

Welding or Joining of the Pipe

The welding of the pipe is done under DOT (Department of Transportation)specifications and requirements (API 1104). A team of highly trained pipe welders will be tested prior to any welding of the pipe.

Non Destructive Examination (NDE)

Once the pipe has been welded, Piedmont Natural Gas has hired a third party firm to inspect every weld to ensure compliance with federal regulations.

Coating of the Pipe Welds

After the examination is completed and the weld is verified to be in compliance, a crew will sandblast and coat each weld with a Fusion Bond Epoxy (FBE) to seal out any moisture and protect the pipeline from corrosion.

Placing the Pipe in the Trench

After coating the welds a crew will install the pipe into the trench. Before the pipe is installed the bottom of the trench is inspected for rocks or other debris that might have fallen in. Once this is complete, pipe-layers or side-booms will lift the pipe for it to be inspected for any damaged coating and repaired. The pipe will then be placed in the trench.

Backfilling the Trench

After the pipe is installed machines will sift the soil and remove any rocks that are in the material that will be used to cover the installed pipe to ensure no damage to the coating. In some cases where rock is all that is available we will haul in sand or other rock free materials to protect the pipe coating.

Testing of the Pipeline

Before any natural gas is transported through a new pipeline, the entire length of the pipeline is pressure tested using water. This is known as hydrostatic testing. This is one of the final construction quality assurance tests before the pipeline is put into operation. Requirements for this test are also prescribed in DOT’s federal regulations.

Depending on the varying elevation of the terrain along the pipeline and the location of available water sources, the pipeline may be divided into sections to facilitate the test. Each section is filled with water and pressured up to a level higher than the maximum pressure at which the pipeline will operate when carrying natural gas. Once the testing is completed a caliper tool (Smart Pig) will be run slowly that will detect any dents in the pipeline that might cause a failure.

Clean up and Restoration

The cleanup and restoration is something Sheehan takes pride in completing because, like you we care about the environment and restoring your property to its original or better condition. A group of highly trained professional will take the time and patience to ensure your satisfaction.

Sheehan Pipe Line is a Family Company that understands families and places. We look forward to starting this project and meeting each of you.

If you have any questions, please contact us at or if you see one of our Foreman or Safety representatives ask them if they can help direct you to the right person or persons.

About Piedmont Natural Gas
Piedmont Natural Gas is an energy services company primarily engaged in the distribution of natural gas to more than one million residential, commercial, industrial and power generation utility customers in portions of North Carolina, South Carolina and Tennessee, including 52,400 customers served by municipalities who are wholesale customers. Our subsidiaries are invested in joint venture, energy-related businesses, including unregulated retail natural gas marketing, and regulated interstate natural gas transportation and storage and intrastate natural gas transportation businesses. More information about Piedmont Natural Gas is available on the Internet at