Large Diameter Pipeline Safety in Design

This paper will focus on engineering controls where implementing best practices in design can have significant impacts on large diameter pipeline safety. The engineering controls include route selection, material selection, specialty fittings and pipeline configuration, trench safety, and pipeline access. The guiding principles of safety in design are founded on implementing engineering controls early in the design process to eliminate or minimize risks throughout the life of the pipeline being designed. The controls begin with hazard identification, considering who will use the facility, who will build it, and who will maintain it. This paper will discuss pipeline route selection, including critical crossings and proximity to existing and future infrastructure and communities; the benefit tradeoff for material selection for the pipe, bedding, backfill, and stabilization; fitting configuration, including considerations for complex or large fitting arrangements, manholes, and occupational safety and health administration (OSHA) requirements for significant trench depth; depth of cover for protection of the pipeline, trench safety, and proximity to static and dynamic loads; and pipeline access, including spacing between access manholes, maximum pipe slope, isolation valves, and dewatering. This paper will present sample case studies to help illustrate some of the aspects of safety.