Faults and treatment measures of corbula-type throttle valves in Yuanba Gas Field

Corbula-type throttle valve is an important valve in controlling the production rate of gas well and the pressure of pipeline network. In order to analyze the causes of the common corbula-type throttle valve faults and study the corresponding treatment measures, In this paper, a case study was carried out on Yuanba High-Sulfur Gas Field. The corbula-type throttle valves in its gas gathering well stations were taken as the study objects and their common faults were summarized, e.g. external leakage, internal leakage, valve pocket embrittlement, bearing damage, foreign matter blockage and valve core's spinning off. Then, combined with the valve design principle, the sealing principle and the external cause analysis, the causes of these common faults were analyzed. It is indicated that they are mainly caused by failed seal assembly, unreasonable valve core design, gas and foreign matter washout, sulfur deposition and hydrate blockage. Finally, some treatment measures were put forward, e.g., replacing the seal assembly and the valve and spraying hot water. Furthermore, a series of countermeasures were prepared, such as providing sufficient spare parts, setting up reasonable gas well working system, and optimizing the design of valve core and the coating material on cemented carbide. The research results provide the theoretical and practical basis for reducing the fault rate of corbula-type throttle valve.