According to the definition of Chinese and American gas pipeline codes and standards, the pig launcher, receiver and pipeline manifold shall be classified as pipeline fittings or piping system components of gas pipeline engineering projects, which are referred to as station equipment in this paper. These facilities are provided for the pigging or scraping of gas pipelines and for the distribution of different phases of natural gas at gathering stations. However, for a long time, these two types of equipment have been inappropriately designed and regulated as pressure vessels in some places or operating units, bringing potential safety risks to the long-term stable and safe operation of these two types of equipment. This paper provides a comprehensive comparison and analysis for the definitions of gas transmission pipeline and pressure vessel in China and the U.S., and a review and insight into the history of the preparation of codes and standards, existing gathering station equipment supervision and technical issues, and also the major technical differences between gas transmission pipeline, station equipment and pressure vessels. Based on the major technical differences between gas pipelines, station equipment and pressure vessels in terms of function, codes and standards, environmental conditions, safety concept on strength, strength and toughness requirements, this research concluded that the pig launcher, receiver and pipeline manifold belong to the gas pipeline gathering station equipment instead of pressure vessel, and should therefore be designed in full accordance with the gas pipeline codes and standards, to prevent any potential safety risks arising from previous practice of treating them as pressure vessels.In addition to analyzing the causes for above issues, this paper proposes two conditions used to determine the classification of pressure vessels, namely their definition and function. Finally, recommendations are given on the technical issues to take note of in the design and fabrication of pig launcher, receivers and pipeline manifolds.