Patent ID: 7874241

Claim:
A trip control system for controlling the operation of a controlled device using fluid pressure delivered from a fluid pressure source to an input of the controlled device, comprising: a fluid pressure line adapted to be connected between the fluid pressure source and the input of the controlled device, the input of the controlled device being a control input that controls the controlled device to move between a first state and a second state when a pressure at the input exceeds a certain amount, wherein the first state is one of an opened or a closed state, and the second state is the other of the opened or the closed state; a low pressure fluid return line; a bleed circuit having a bleed valve system hydraulically and directly coupled between the fluid pressure line and the low pressure fluid return line, the bleed circuit disposed upstream of the input of the controlled device and the bleed valve system operable to hydraulically and controllably connect the fluid pressure line to the low pressure fluid return line to reduce the fluid pressure within the fluid pressure line; and a block circuit disposed at least partially in the fluid pressure line upstream of the bleed circuit and coupled to the low pressure fluid return line, the block circuit including: a first valve and a second valve disposed in series in the fluid pressure line, the first and the second valve each operable to completely block the fluid pressure line; and first and second electronically controlled actuators hydraulically coupled to the first and second valves to control the operation of the first and second valves, the first and second electronically controlled actuators adapted to receive control signals to control the operation of the first and second valves.