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

Abstract

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.

1 . A method of deactiving 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 from a floating vessel with a hose reel that is located at the water surface area;   c) using the device of steps “a” and “b” to cut an underwater object;   d) wherein the hose reel of step “b” includes first and second hydraulic hoses that connect to the cylinder on opposing sides of the piston;   e) providing a hydraulic pump and hydraulic fluid reservoir on the floating vessel at the water surface area for providing the hydraulic fluid under pressure to said first and second hydraulic hoses via third and fourth hydraulic hoses;   f) intermittently monitoring fluid flow in the first and second hydraulic hoses;   g) 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;   h) intermittently monitoring a first and second volume of the hydraulic fluid flowing respectively in the third and fourth hydraulic hoses with a first flow meter interfaced with the third hydraulic hose, wherein the first flow meter measures fluid flow in the third hydraulic hose and a second flow meter interfaced with the fourth hydraulic hose, wherein the second flow meter measures fluid flow in the fourth hydraulic hose, said third and fourth hoses including a pressure line that transmits hydraulic fluid from the pump to the hose reel and a return flow line that returns hydraulic fluid from the hose reel to the hydraulic fluid reservoir;   i) providing a control valve that is interfaced with the third and fourth hydraulic hoses at a position in between said flow meters and said hydraulic pump and reservoir, said control valve having a control that enables reversal of fluid flow in said third and fourth hydraulic hoses so that the third hydraulic hose functions as the return line and the fourth hydraulic hose functions as the pressure line;   j) deactiving the hydraulic device if the ratio varies from a preset ratio or preset value; and   k) using the control valve of step “i” to change flow direction in said third and fourth hydraulic hoses.   
     
     
         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 “f”, 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 “j”, 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 “j” the engine is shut off. 
     
     
         7 . The method of  claim 1  wherein a controller continuously monitors flow in the flow meters and continuously calculates the ratio of step “g”. 
     
     
         8 . The method of  claim 7  further comprising providing a selector switch having multiple selectable switch positions and wherein the ratio of step “g” can be varied by selecting a different position of the selector switch. 
     
     
         9 . The method of  claim 7  wherein the computer uses a different ratio depending upon which switch position is selected and the dimensions of the cylinder and cylinder rod of the selected device. 
     
     
         10 . The method of  claim 1  wherein the volumes of step “g” are automatically calculated. 
     
     
         11 . A method of deactiving a hydraulic device, comprising the
 a) providing a floating vessel with a control station, a prime mover, a hydraulic pump powered by said prime mover and a pump fluid reservoir that supplies hydraulic fluid to the pump;   b) providing a hydraulic device that is capable of being operated under water, the device having a hydraulic cylinder with a pushrod and a piston;   c) lowering the device below a water surface with a hose reel that is located at the water surface area;   d) using the hydraulic device to cut an underwater object;   e) wherein the hose reel of step “c” includes first and second hydraulic hoses that connect to the cylinder on opposing sides of the piston;   f) intermittently monitoring fluid flow in the first and second hydraulic hoses;   g) monitoring hydraulic fluid flow in third and fourth hydraulic hoses with a first flow meter and a second flow meter, wherein the first flow meter is in a third flow line that is located in between the hose reel and hydraulic pump and the second flow meter is in a fourth flow line that is located in between the hose reel and pump fluid reservoir;   h) connecting each of said third and fourth flow lines to a control valve that is in between said flow meters and said pump and reservoir, said control valve having a control that enables flow reversal in said third and fourth flow lines so that the third flow line is a pressure flow line in a first control valve position and a return flow line in a second control valve position and the fourth flow line is a return flow line in a first control valve position and a pressure flow line in a second control valve position;   i) calculating a ratio of a first volume of fluid in the first hydraulic hose that enters a pushrod retraction chamber section of the hydraulic cylinder to a second volume of fluid in the second hydraulic hose that enters a pushrod extension chamber of the hydraulic cylinder; and   j) deactiving the hydraulic device if the ratio varies from a preset value.   
     
     
         12 . The method of  claim 11  wherein the flow is measured with first and second flow meters in step “f”, 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 “j”, the prime mover and pump assembly is deactivated. 
     
     
         14 . The method of  claim 13  wherein the prime mover is an engine and in step “j” the engine is shut off. 
     
     
         15 . The method of  claim 11  wherein a controller continuously monitors flow in the flow meters and continuously calculates the ratio of step “i”. 
     
     
         16 . The method of  claim 11  further comprising providing a selector switch having multiple selectable switch positions and wherein the ratio can be varied by selecting a different position of the selector switch. 
     
     
         17 . A hydraulic power unit leak detection apparatus, comprising:
 a) a floating vessel having a control station that includes a storage reel, a prime mover, a pump and a pump fluid reservoir;   b) a hydraulic device that is operated with a prime mover and pump, and wherein the hydraulic device includes a hydraulic cylinder having a cylinder, pushrod, and piston;   c) 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;   d) a first hydraulic fluid flow line that supplies hydraulic fluid to the first chamber;   e) a second hydraulic flow line that supplies hydraulic fluid to the second chamber;   f) the storage reel holding a first hydraulic fluid flow line that supplies the hydraulic fluid to the first chamber;   g) a third flow line in between the pump and hose reel;   h) a fourth flow line that is in between the hose reel and the pump fluid reservoir;   i) a first flow meter in said third flow line wherein said first flow meter measures fluid flow upstream of said storage reel;   j) the storage reel holding a second hydraulic flow line that supplies the hydraulic fluid to the second chamber;   k) a second flow meter in said fourth flow line that measures fluid flow upstream of said storage reel;   l) 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;   m) the computer monitoring hydraulic fluid flow in the third and fourth hydraulic hoses with said first and second flow meters; and   n) 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.   
     
     
         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 apparatus 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 method of  claim 1  further comprising a hose reel that enables the device to be lowered to a sea bed area. 
     
     
         26 . The method of  claim 1  wherein multiple hydraulic flow lines are part of the hose reel. 
     
     
         27 . The method 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 method of  claim 27  wherein each flow meter is in a said hydraulic hose in between the hose reel and the device.