Evaluation of the “occlusion effect” in the outlet section of a defective opening in a pipeline during outflow of liquefied hydrocarbon gases

The “occlusion effect” of the outlet portion of a defective opening in a product line during discharge of liquefied hydrocarbon gases (LHG) is evaluated. It is ascertained that the occlusion effect is proportional to the ratio of the wall thickness of the product line (the length of the channel of the defective opening) to the diameter of the opening, and is explained by rapid evaporation of LHG in the channel of the opening, and crystallization of the water vapor contained in the air owing to rapid cooling.