Reliability Analysis of Hydraulic Directional Control Valve Installed in Subsea Control Module

This paper explores hybrid life distribution, instead of constant failure rate, based on the exponent and Gamma model to analyze the reliability of hydraulic directional control valve (HCV). The article shows that HCV reliability has not only to do with the pulse frequency of pilot valve but also to the hydraulic latching time of main valve, the failure rate not to be constant is with respect to the parameters of the hybrid life distribution model. This paper discusses the cold standby and the 1oo2 configuration applied to dual redundant coils, concluding that the latter is priority to the former and can extend the service life of the HCV. A simulation example shows the effectiveness.