A method of deactiving an underwater hydraulic device provides a hydraulic device that is capable of being operated under water, the device having a hydraulic cylinder with a pushrod and a piston. The device is lowered below a water surface with a hose reel that is located at the water surface area such as on a marine vessel. The hose reel includes first and second hydraulic hoses that connect to the cylinder on opposing sides of the piston. Fluid flow in the first and second hydraulic hoses is continuously monitored. The ratio of the volume of fluid flowing into the cylinder from one side of the piston to the volume of fluid flowing into the cylinder from the other side of the cylinder is continuously calculated with a computer or controller. The hydraulic device is deactivated if the ratio varies from a preset value. One embodiment includes a plurality of flow meters for measuring fluid flow to and from one or more hydraulicly powered apparatuses. In one embodiment outputs of the flow meters are analyzed to determine if the hydraulic system has a leak, and if a leak is detected, a warning is issued and/or one or more of the connected hydraulically powered apparatuses are shut down, and/or the hydraulic power supply is shut down.

A method of deactiving an underwater hydraulic device provides a hydraulic device that is capable of being operated under water, the device having a hydraulic cylinder with a pushrod and a piston. The device is lowered below a water surface with a hose reel that is located at the water surface area such as on a marine vessel. The hose reel includes first and second hydraulic hoses that connect to the cylinder on opposing sides of the piston. Fluid flow in the first and second hydraulic hoses is continuously monitored. The ratio of the volume of fluid flowing into the cylinder from one side of the piston to the volume of fluid flowing into the cylinder from the other side of the cylinder is continuously calculated with a computer or controller. The hydraulic device is deactivated if the ratio varies from a preset value. One embodiment includes a plurality of flow meters for measuring fluid flow to and from one or more hydraulicly powered apparatuses. In one embodiment outputs of the flow meters are analyzed to determine if the hydraulic system has a leak, and if a leak is detected, a warning is issued and/or one or more of the connected hydraulically powered apparatuses are shut down, and/or the hydraulic power supply is shut down.

A valve unit includes a first piston, which has a first opening and a control chamber. A fluid connection between a first and a second port is closed or, in a position defined by the first piston, is held open in the event that a hose which is connected to the first port bursts. A pilot valve (48) is present, which has a core and a coil, and a fluid flow from the control chamber to the first port can be regulated by an electric current in the coil. The current is regulated by a logic unit which is suitable for receiving signals from at least one sensor, in particular a pressure sensor, an inertia detector and/or position sensor and for regulating the electric current in the coil.

A valve unit includes a first piston, which has a first opening and a control chamber. A fluid connection between a first and a second port is closed or, in a position defined by the first piston, is held open in the event that a hose which is connected to the first port bursts. A pilot valve (48) is present, which has a core and a coil, and a fluid flow from the control chamber to the first port can be regulated by an electric current in the coil. The current is regulated by a logic unit which is suitable for receiving signals from at least one sensor, in particular a pressure sensor, an inertia detector and/or position sensor and for regulating the electric current in the coil.

A method of deactivating an underwater hydraulic device includes providing a hydraulic device operable under water, the device having a hydraulic cylinder with a pushrod and a piston. The device is lowered below a water surface with a hose reel that is located at the water surface area such as on a marine vessel. The hose reel includes first and second hydraulic hoses that connect to the cylinder on opposing sides of the piston. Fluid flow in the first and second hydraulic hoses is continuously monitored. The ratio of the volume of fluid flowing into the cylinder from one side of the piston to the volume of fluid flowing into the cylinder from the other side of the cylinder is continuously calculated with a computer or controller. The hydraulic device is deactivated if the ratio varies from a preset value.

A method of deactivating an underwater hydraulic device includes providing a hydraulic device operable under water, the device having a hydraulic cylinder with a pushrod and a piston. The device is lowered below a water surface with a hose reel that is located at the water surface area such as on a marine vessel. The hose reel includes first and second hydraulic hoses that connect to the cylinder on opposing sides of the piston. Fluid flow in the first and second hydraulic hoses is continuously monitored. The ratio of the volume of fluid flowing into the cylinder from one side of the piston to the volume of fluid flowing into the cylinder from the other side of the cylinder is continuously calculated with a computer or controller. The hydraulic device is deactivated if the ratio varies from a preset value.

A pressure regulator device for use within a pressure-regulated fluid storage and dispensing vessel primarily in low flow, low delivery pressure applications. Regulator stiction challenges have been solved with an improved poppet assembly using different poppet element configurations as well as an improved bellows structure in the pressure-sensing assembly that provides more flexibility during contraction and expansion of the diaphragm elements.

A pressure regulator device for use within a pressure-regulated fluid storage and dispensing vessel primarily in low flow, low delivery pressure applications. Regulator stiction challenges have been solved with an improved poppet assembly using different poppet element configurations as well as an improved bellows structure in the pressure-sensing assembly that provides more flexibility during contraction and expansion of the diaphragm elements.

A pressure relief valve includes the following features. A housing defines an inlet and an outlet. The housing defines a flow passage between the inlet and the outlet. A seat can be defined by the housing. The seat defines a throat flow area. A plunger is configured to rest upon the seat. The plunger blocks the flow passage when in a closed position. The plunger is configured to actuate between a fully open position and the closed position. The plunger and the seat can at least partially defining a curtain flow area. A bias directs the plunger towards the seat. A ratio of the throat flow area to the curtain flow area is sized for sonic or supersonic flow velocities during critical flow conditions and subsonic velocities during subcritical flow conditions.

A pressure relief valve includes the following features. A housing defines an inlet and an outlet. The housing defines a flow passage between the inlet and the outlet. A seat can be defined by the housing. The seat defines a throat flow area. A plunger is configured to rest upon the seat. The plunger blocks the flow passage when in a closed position. The plunger is configured to actuate between a fully open position and the closed position. The plunger and the seat can at least partially defining a curtain flow area. A bias directs the plunger towards the seat. A ratio of the throat flow area to the curtain flow area is sized for sonic or supersonic flow velocities during critical flow conditions and subsonic velocities during subcritical flow conditions.