Valve Placement and Operation for Liquid Transmission Pipelines: A Risk Reduction Tool

The Intelligent Valve Placement (IVP) approach has been developed to incorporate risk (defined as likelihood × consequence) reduction techniques to identify optimum locations for sectionalizing (block) valves along existing or new petroleum transmission pipelines. This process aims to optimize valve placement based on risk reduction rather than current rule-of-thumbs and regulatory requirements. It may result in cost reduction and cost optimization through efficient valve placement while meeting required regulations. This approach incorporates risk through reduction of consequence, which is achieved by reducing the potential spill volumes and impact to sensitive areas in an iterative manner. With the use of consequence reduction strategies, this paper demonstrates that valve placement and operability decisions on both new or existing pipelines can be made to optimize the location of valves and provide for a safer pipeline. Although this process is highly consequence driven, there are opportunities to incorporate likelihood drivers. Equations have been developed that quantify consequence reduction and allow for determination of an optimal valve placement design. Application of this technique to pipelines in the United States is presented and the limitations of this method addressed. Although this technique is valid anywhere, this approach is in line with the requirement from the U.S. Department of Transportation to examine the placement of emergency flow restricting devices as per the High Consequence Area ruling and the requirements set forth by the Canadian Standards Association regarding remote operation of valves in Canada consistent with “extraordinary hazard” determinations.