Method and apparatus for deactivating a hydraulic device that is leaking hydraulic oil

Abstract

A method of deactivating 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 piston 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 hydraulically 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. In one embodiment, the flow lines are jointed flow lines comprised of hose joints connected end to end. Some or all of the hoses have check valves. In one embodiment, the check valves stop flow in either direction if the flow pressure drops below a selected pressure.

1 . A method of deactivating an underwater hydraulic device, comprising the steps of:
 a) providing a hydraulic device that is capable of being operated under water, the device having a hydraulic cylinder with a pushrod and a piston;   b) lowering the device below a water surface with a hose reel that is located at the water surface area;   c) wherein the hose reel of step “b” includes first and second hydraulic hoses that connect to the cylinder on opposing sides of the piston;   d) intermittently monitoring fluid flow in the first and second hydraulic hoses;   e) calculating 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 piston;   f) deactivating the hydraulic device if the ratio varies from a preset ratio or preset value; and   g) wherein the hoses are a plurality of joints, wherein a plurality of said joints house a check valve.   
     
     
         2 . The method of  claim 1  wherein the device is a hydraulic shear. 
     
     
         3 . The method of  claim 1  wherein the flow is measured with first and second flow meters in step “d”, one flow meter monitoring fluid flow in the first hydraulic hose, the other flow meter monitoring flow in the second hydraulic hose. 
     
     
         4 . The method of  claim 1  wherein the hydraulic device receives hydraulic fluid under pressure from a prime mover and hydraulic pump assembly and in step “f”, the prime mover and pump assembly is deactivated. 
     
     
         5 . The method of  claim 4  wherein the prime mover is deactivated. 
     
     
         6 . The method of  claim 5  wherein the prime mover includes an engine and in step “f” the engine is shut off. 
     
     
         7 . The method of  claim 3  wherein a controller continuously monitors flow in the flow meters and continuously calculates the ratio of step “e”. 
     
     
         8 . The method of  claim 7  further comprising providing a selector switch having multiple selectable switch positions and wherein the ratio of step “e” can be varied by selecting a different position of the selector switch. 
     
     
         9 . The method of  claim 8  wherein the computer uses a different ratio depending upon which switch position is selected and the dimensions of the cylinder and pushrod of the selected device. 
     
     
         10 . The method of  claim 1  wherein the volumes of step “e” are automatically calculated after step “d”. 
     
     
         11 . A method of deactivating a hydraulic device, comprising the steps of:
 a) providing a hydraulic device having a cylinder with a pushrod and a piston, the device receiving flow from a jointed flow line;   b) wherein the flow line of step “a” includes first and second hydraulic jointed hoses that connect to the cylinder on opposing sides of the piston;   c) intermittently monitoring fluid flow in the first and second hydraulic hoses;   d) continuously comparing the volume of fluid that enters a pushrod retraction chamber section of the cylinder with a pushrod extension section of the cylinder;   e) deactivating the hydraulic device if the ratio varies from a preset value; and   f) wherein the hoses are a plurality of hose joints, wherein a plurality of said hose joints are connected together end to end with connectors that each house a check valve.   
     
     
         12 . The method of  claim 11  wherein the flow is measured with first and second flow meters in step “c”, one flow meter monitoring fluid flow in the first hydraulic hose, the other flow meter monitoring flow in the second hydraulic hose. 
     
     
         13 . The method of  claim 11  wherein the hydraulic device receives hydraulic fluid under pressure from a prime mover and hydraulic pump assembly and in step “e”, the prime mover and pump assembly is deactivated. 
     
     
         14 . The method of  claim 13  wherein the prime mover is an engine and in step “e” the engine is shut off. 
     
     
         15 . The method of  claim 12  wherein a controller continuously monitors flow in the flow meters and continuously calculates the ratio of step “d”. 
     
     
         16 . The method of  claim 11  further comprising providing a selector switch having multiple selectable switch positions and wherein the ratio of step “e” can be varied by selecting a different position of the selector switch. 
     
     
         17 . A hydraulic leak detection apparatus, comprising:
 a) a hydraulic device that is operated with a prime mover, pump, and hydraulic cylinder having a cylinder, a pushrod, and a piston;   b) the cylinder having a first chamber that is receptive of hydraulic fluid when extending the pushrod and a second chamber that is receptive of hydraulic fluid when retracting the pushrod;   c) a first hydraulic flow line that supplies hydraulic fluid to the first chamber;   d) a second hydraulic flow line that supplies hydraulic fluid to the second chamber;   e) at least one of said flow lines being comprised of separate lengths of hose connected end to end;   f) a computer that continuously monitors the ratio of the volume of fluid entering the first chamber to the volume of fluid entering the second chamber;   g) the computer operatively connected to the prime mover so that the computer can deactivate the prime mover when the ratio varies from a preset acceptable value of said ratio; and   h) at least one of the hydraulic flow lines being comprised of a plurality of hose joints that are joined together with connectors that each contain a check valve.   
     
     
         18 . The apparatus of  claim 17  wherein the hydraulic device is a power tong. 
     
     
         19 . The apparatus of  claim 17  wherein each of said first and second flow lines has a flow meter interfaced with said computer so that the flow meters continuously transmit flow data to the computer. 
     
     
         20 . The apparatus of  claim 17  further comprising a selector switch that enables the computer to compare the said ratio with a selected one of a plurality of ratios, each ratio of the plurality of ratios corresponding to different hydraulic cylinder configurations. 
     
     
         21 . The apparatus of  claim 17  further comprising a selector switch that enables the computer to compare the said ratio with a selected one of a plurality of ratios, each ratio of the plurality of ratios corresponding to different hydraulic cylinder dimensions. 
     
     
         22 . The apparatus of  claim 17  wherein the computer is programmable to designate any ratio as the acceptable value. 
     
     
         23 . The method of  claim 17  wherein the acceptable value is a range. 
     
     
         24 . The apparatus of  claim 22  wherein the acceptable value is a range. 
     
     
         25 . The apparatus of  claim 17  further comprising a hose reel that enables the device to be lowered to a sea bed area. 
     
     
         26 . The apparatus of  claim 25  wherein multiple hydraulic flow lines are part of the hose reel. 
     
     
         27 . The apparatus of  claim 25  wherein each of said first and second hydraulic hoses has a flow meter interfaced with a computer or controller so that the flow meters continuously transmit flow data to the computer. 
     
     
         28 . The apparatus of  claim 27  wherein each flow meter is in a said hydraulic hose in between the hose reel and the device.