Overview

Based on several pipe anomalies discovered during a recent in-line inspection and an inspection dig, as well as the anticipated population growth for the local area, it was necessary for the owner of a natural gas pipeline in western PA to upgrade the pipeline and launcher/ receiver.

This portion of their distribution network was 3.1 miles in length. The most recent in-line inspection (ILI) indicted that there were more than 16,000 defects with wall loss greater than 20%, with 40 of those defects requiring near term attention. Additionally, the communities around the project area were poised for significant population growth, with housing developments planned within approximately 4,300 feet of the affected pipeline.

Portions of the distribution system were constructed with uncoated Grade B pipe, originally installed in 1952. The project included replacement of 30 different segments of this original pipe spread out over 2.7 miles. An NPS 20 launcher and NPS 20 receiver were replaced with bi-directional launchers/receivers.

The 2022 Pressure Test Program project included 13 pressure test projects prioritized for the pipeline systems. There was a need to pressure test these pipeline sections of varying lengths and sizes for due to changes in hazardous classifications from land use changes caused by population growth along the pipeline routes. These test sections were identified following a review of covered segments based on threat-specific and total risk scores for the likelihood of failure in accordance with TEP-IN-SWRA-GE System Wide Risk Assessment Procedure. The project aligned with our client’s Integrity Management Plan.

In cases where drawings of existing pipelines were not available, initial surveys were completed to develop “as-found” drawings for the basis for design. Access roads were established to each end of the test sections. Testing result calculations were prepared for the owner with accompanying as-built drawings for each of the 13 test sites.