Patent ID: 8893803

Claim:
A subsea relief valve system for use in a subsea environment, the subsea relief valve system comprising: a subsea piping having a first portion and a second portion, said first portion having a higher pressure rating than a pressure rating of said second portion; a choke cooperative with said subsea piping, said choke being movable between an open position and a closed position, said open position suitable for venting a fluid to the subsea environment when a pressure of a fluid in said first portion of said subsea piping exceeds the pressure rating of said second portion of said subsea piping, said closed position suitable for retaining the fluid in the subsea piping; a hydraulic actuator connected to said choke so as to move said choke between said closed position and said open position, said hydraulic actuator comprising: a cylinder; and a piston slidably positioned in said cylinder, said piston operatively connected to said choke, said piston defining a first chamber and a second chamber within said cylinder; and a first hydraulic line connected to said cylinder so as to be in communication with said first chamber; a hydraulic fluid supply in communication with said first hydraulic line; a first valve positioned between said hydraulic fluid supply and said first chamber, said first valve movable between an open position and a closed position, said open position of said valve allowing hydraulic fluid to pass from said hydraulic fluid supply through said first hydraulic line to said first chamber of said cylinder, said closed position of said first valve blocking hydraulic fluid from passing from said hydraulic fluid supply to said first chamber of said cylinder; and a sensor cooperating with said first portion of said piping so as to sense a pressure of the fluid in said first portion of said piping; and a controller cooperative with said sensor and with said first valve so as to move said first valve to said open position when the pressure of the fluid in said first portion of said piping exceeds the pressure rating of said second portion of said piping so that said piston moves said choke to said open position.