Safety distance for leakage-induced explosion of long-distance parallel buried gas pipelines

Explosion induced by leakage of long-distance parallel buried gas pipelines may threat safety of nearby pipelines. Accordingly, the coupling model with combination of smoothed particle hydrodynamics (SPH) and finite-element method is used to determine structure responses of parallel pipelines and corresponding safety distances under the impacts of shock waves. The results show that destructions of long-distance parallel pipelines induced by explosion include over-pressure destructions caused directly by shock waves and those caused by plastic squeezing of soil. The later form of destruction is dominant. Surfaces of the pipelines directly facing the center of explosion are significantly subject to impacts of explosion and accordingly more susceptible to failure. Safety distance between long-distance parallel buried gas pipelines with steel of X80, OD of 1 219 mm, pressure of 12 MPa and wall thickness of 22 mm shall be 10 m, while safety distance between long-distance parallel buried gas pipelines with wall thicknesses of 26.4 mm and 27.5 mm shall be 9 m with the same other conditions as the former. To ensure production safety, distance between long-distance parallel pipelines shall be increasedin priority, the wall thicknesses of pipelines used shall be increased in the next during installation of long-distance parallel buried gas pipelines.