Abstract: A case analysis on valve casing cracking has been made for the pump stations in Zhong-Luo parallel oil pipeline. It is pointed out that on the one hand the expanding ice freezed from the water deposited within the valve casing produced an axial thrust that made the casing tensioned, and on the other hand the poor low-temperature brittleness of the casing material as well as the internal and external differential tempera-ture pressures of the valve casing were existed, which is the main reason of valve casing cracking. The improvement recommendations on the quality of this kind of valve have been given.