Abstract: A laser piston position sensor for determining the position of a piston within an accumulator, the laser piston position sensor configured to attach to an end of the accumulator, and the accumulator having an aperture in the end thereof exposing the piston within the accumulator to the laser piston position sensor. The laser piston position sensor including a sensor housing enclosing a cavity containing a low pressure gas, and defining an opening from the cavity toward the accumulator, a laser sensor positioned within the cavity for emitting a laser toward the piston of the accumulator via the opening in the sensor housing and the aperture in the accumulator, and a transparent lens positioned between the laser sensor and the accumulator to allow passage of the laser from the laser sensor to the piston, and to separate gases in the accumulator from gases in the cavity of the sensor housing.

Abstract: A subsea blowout preventer control system has horizontally oriented solenoid valve housings. Solenoid valves mounted within each of the solenoid valve housings are electrically controlled to selectively provide a hydraulic pilot signal to a hydraulic valve. A vertically extending central chamber contains a dielectric liquid and extends alongside the solenoid valve housings. A communication tube for each solenoid valve housing has an open upper end within the central chamber adjacent an upper end of the central chamber. Each of the communication tubes has an open lower end extending into one of the solenoid valve housings for communicating dielectric liquid in the central chamber with an interior of each of the solenoid valve housings. A separate drain line mounted to each of the solenoid valve housings enables draining of one of the solenoid valve housings for maintenance without requiring draining of other of the solenoid valve housings.

Abstract: A laser piston position sensor for determining the position of a piston within an accumulator, the laser piston position sensor configured to attach to an end of the accumulator, and the accumulator having an aperture in the end thereof exposing the piston within the accumulator to the laser piston position sensor. The laser piston position sensor including a sensor housing enclosing a cavity containing a low pressure gas, and defining an opening from the cavity toward the accumulator, a laser sensor positioned within the cavity for emitting a laser toward the piston of the accumulator via the opening in the sensor housing and the aperture in the accumulator, and a transparent lens positioned between the laser sensor and the accumulator to allow passage of the laser from the laser sensor to the piston, and to separate gases in the accumulator from gases in the cavity of the sensor housing.

Abstract: A subsea blowout preventer control system has horizontally oriented solenoid valve housings. Solenoid valves mounted within each of the solenoid valve housings are electrically controlled to selectively provide a hydraulic pilot signal to a hydraulic valve. A vertically extending central chamber contains a dielectric liquid and extends alongside the solenoid valve housings. A communication tube for each solenoid valve housing has an open upper end within the central chamber adjacent an upper end of the central chamber. Each of the communication tubes has an open lower end extending into one of the solenoid valve housings for communicating dielectric liquid in the central chamber with an interior of each of the solenoid valve housings. A separate drain line mounted to each of the solenoid valve housings enables draining of one of the solenoid valve housings for maintenance without requiring draining of other of the solenoid valve housings.

Abstract: A blowout preventer control system includes a valve block having a solenoid valve face and a hydraulic valve face. Solenoid valve cavities extend into the valve block front the solenoid valve face, each solenoid valve cavity containing an electrically actuated solenoid valve. Hydraulic valve cavities extend into the valve block from the hydraulic valve face, each containing a hydraulic valve. A solenoid valve supply passage in the valve block joins each of the solenoid valve cavities. A solenoid valve pilot passage in the valve block extends from one of the solenoid valve cavities to tine of the hydraulic valves. A hydraulic valve supply passage in the valve block joins each of the hydraulic valve cavities. A hydraulic valve outlet passage extends from each of the hydraulic valve cavities out of the valve block.