LNG Facility Siting – An Alternative Approach for Vapor Cloud Reduction
Abstract
The siting of Marine LNG facilities in the United States requires application of the Title 49 of the Code of Federal Regulations (CFR) Part 193, Liquefied Natural Gas Facilities: Federal Safety Standards[1], and NFPA 59A – 2001 Edition, Standard for the Production, Storage, and Handling of Liquefied Natural Gas [2]. In addition, the guidance for LNG siting application available in the PHMSA (US DOT Pipeline and Hazardous Materials Safety Administration) web site is also required. One of the most important items for LNG facility siting is the Hazards Analysis, which consists in the identification of the SALS (Single Accidental Leakage Source) by analyzing all piping in the facility. The SALSs for conventional piping are defined based on the size and length of the lines and the application of a failure rate table provided by PHMSA [3]. This methodology may generate scenarios with large flammable gas clouds, especially for long lines such as the LNG loading line and rundown line. Vapor barriers are a design solution acceptable by the regulators and commonly used to prevent vapor clouds from reaching a property that could be built upon [4]. This paper presents the application of Pipe-in-Pipe (PiP) technology for the LNG rundown line and the LNG loading line (which runs over a marine trestle). The Pipe-in-Pipe consists of an inner pipe designed for the process conditions of the particular service, insulation material wrapping the inner pipe, and an outer pipe. The outer pipe is designed to provide full containment in the unlikely event of a leak from the inner pipe and to withstand any thermal deformation due to exposure to cryogenic temperatures. Any leakage from the inner pipe is directed to the flare system. With the application of PiP technology for the LNG loading line and rundown line, any potential leaks in the inner piping will be contained by the outer pipe and directed to a safe disposition. If approved by FERC and USCG, this technology will allow proposed LNG projects the potential for reduced flammable gas clouds, reducing the need for other mitigations, such as vapor barriers. Another advantage of the PiP technology is that any leak in the marine area will be contained by the outer pipe, allowing the reduction of the liquid containment system for facilities with long trestles over water.
Description
PresentationSubject
LNG facilitiy sitingCollections
Citation
Santos, Francisco P.; Raaf, James D.; Kenefake, Daryl A. (2016). LNG Facility Siting – An Alternative Approach for Vapor Cloud Reduction. Mary Kay O'Connor Process Safety Center; Texas &M University. Libraries. Available electronically from https : / /hdl .handle .net /1969 .1 /193656.