This invention relates to a vessel sinking protection system and more particularly to a convenient pneumatic failsafe system for closing seacocks.
A major cause of vessel sinking is the failure to close seacocks when the vessel is at anchor or docked. Recent insurance industry estimates report that for every boat that sinks at sea four boats sink while safely moored at their slips. Of those that are safely moored at their slips half of these sinkings are due to seacock failure. Thus for every boat that sinks at sea there are at least two that sink because their seacocks fail while they were sitting at the dock.
The failure of seacocks happens for two main reasons; a leak in the seacock or a leak in the line or hose from the seacock to the device or unit that the seacock is coupled to. Thus, for instance, a hose that is coupled to a seacock and is run to a device or a unit may come off of the seacock due to improper double-clamping. Secondly, even if the hose to the seacock is intact, if the hose lets loose from the device or unit to which it is attached and then extends down below the water line the vessel will fill with water and sink.
A major problem with manually operated seacocks is that they are very inaccessible and must often times be closed with a wrench that may be temporarily lost. Thus, in an emergency there may be no manual way to close up all the seacocks to prevent flooding, Moreover, one may not want to close all of the seacocks involved if it can be ascertained which seacock is responsible for the vessel flooding.
An electric solenoid system exists to close seacocks. However electricity may not be available as a vessel floods due to battery failure. Therefore these systems are ineffective precisely at the time when they should be effective to prevent the sinking of the vessel during an emergency.
It will be appreciated that a seacock is any valve that is below the water line and is utilized for instance to admit raw sea water into such devices as an engine, a refrigeration unit or a water purification unit, or for shooting out waste.
As will be appreciated, the operator of the vessel is supposed to close all of the seacocks when the vessel is moored, because if a hose pops off and if it is below the water line, sea water floods the boat, filling it quickly and the vessel sinks.
While relatively large ocean going vessels have hydraulically controlled sea water valves, due to the fact it takes so much force to open these large valves, smaller boats are left to manual operation of their seacocks.
While operators of smaller boats want to be able to close the seacock or valve causing the trouble, they may also want to be able to leave other valves open, for instance to leave the raw water intake seacock for the engine open. Moreover, it may be desirable to have a seacock open if the faulty seacock or line is to a non-critical unit such as a head. It is thus important to be able to shut off the affected seacock without closing an unaffected seacock. Thus, it is desirable to be able to leave selected seacocks open, especially the seacock that is utilized to provide for the ingest of water to cool an engine, if the engine seacock is functioning correctly.
On the other hand, prior to ascertaining what seacocks and lines have failed, one would very much like to have a convenient and fail safe system for closing all of the seacocks to allow the operator to figure out which seacock or associated line is leaking or has failed. Once the leaking seacock has been diagnosed, it is desirable to have the operator can keep open the seacocks that are working properly.
For instance, if one is offshore fishing and one has discovered that a seacock is leaking, one could still operate un-affected equipment while simply keeping the affected seacock closed, allowing the boat to reach port where the affected seacock and associated line can be repaired.
Additionally, in terms of manual operation of seacocks or thru-hull valves, often-times manual operation requires a lever that is six inches long. There must thus be at least 6 inches of clearance around the seacock in order to be able to manually activate the seacock valve. Since these seacocks are in inaccessible spaces, it is either inconvenient or near impossible to be able to manually close a seacock. Moreover, depending on the seacock size and style it usually takes about 35 pounds of pressure to open and close a seacock, which means it takes 70 pounds of force that one has to exert on the seacock valve in order to open or close it. For many seacocks they are in a place where one cannot physically exert that much force on the valve.
Prior systems have been utilized to close off water inlet valves such as illustrated in U.S. Pat. Nos. 6,786,782; 5,947,047; 6,343,965; and 4,697,535. It is apparent from the above that there are no retrofit pneumatically operated systems to close all seacocks either for convenience or in an emergency.
Those systems requiring electricity are shown in U.S. Pat. Nos. 5,947,047 and 4,697,535, both of which operate with electrical power to close valves. It is important not to have electrically operated seacocks because the seacocks are located in a very damp and corrosive environment. It is noted that electrical systems generally do not last indefinitely in such environments. As mentioned above, when the sea water gets above battery level, the entire electrical system shorts out and one has no electricity aboard.
Referring now to U.S. Pat. No. 6,786,782, it will be appreciated that pneumatic valve actuation is described. However, it can be seen that the pneumatic valve actuator is placed on top of the seacock, meaning that an additional piece of apparatus must be added in series with the seacock to be able to shut off the water flow. A pneumatically actuated valve in series with the seacock is both cumbersome because it adds additional structure on top of the seacock, and is also counterproductive in that a failure can occur between the seacock and the pneumatically actuated valve. As a result, its use with existing seacocks is problematic.
In order to close a particular valve utilizing this patent, positive pressure must be maintained in order to keep the valve closed. Thus, for instance, in the piston arrangement shown, since it is spring loaded to keep the valve open, pressure must be continuously applied to the piston in order to keep the valve shut. This requires a constant source of pressure and a large reservoir.
Further and as will be appreciated, U.S. Pat. No. 6,343,965 relates to a pneumatically-actuated marine engine water drain system in which the water drains into the bilge of a boat or overboard. However, as can be seen, here there is no seacock.
Most importantly, not shown in the above-described art is the ability to close all of the seacocks in an emergency situation in which pneumatic closure overrides the actuation of any of the open seacocks. Moreover, nowhere is shown the ability to selectively open unaffected seacocks so that once the emergency situation has been addressed through the closing of all the seacocks, non-critical seacocks can be reopened for normal operation.
In order to provide a convenient way of controlling seacocks and/or for vessel sinking protection, a failsafe system is provided for closing all of the seacocks in a vessel and thereafter selectively opening unaffected seacocks. In the subject system a pneumatically-driven seacock valve stem actuator is provided for each seacock in which in one embodiment an adapter is fitted over the manually actuated valve stem which protrudes from the side of the seacock housing, with the adapter being powered by a pneumatic rotary actuator, in one embodiment a rack and pinion rotary actuation system to pneumatically move the seacock from an open position to a closed position and vice versa.
While the above applies to original seacock installations, a retrofit package may be used to retrofit existing seacocks with pneumatic actuation. Moreover, in one embodiment the normal seacock handle remains in place for manual operation.
In one embodiment, the adapter is bolted to the flange of the seacock through a mounting bracket or collar that saddles the seacock and positions the rotary actuator over the flange of the seacock. This collar piggybacks on the bolts that anchor the seacock such that it is unnecessary to modify the seacock for retrofitting.
The reason that this retrofit is successful is that all seacocks of either ball type or tapered cone type have a valve stem to control the position of the internal system.
The aforementioned adapter fits over this rod and engages the valve stem. As a result, the retrofit involves removing the handle and slipping on the adapter so that it only contacts the flats and not the threads. Thus there is no damage to the seacock.
Note that the adapter is kept tight against the seacock by the design of the mounting collar which pulls the rotary actuator tight against the seacock. The adapter contacts the bolt in a loose fit such that the adapter can float slightly about an eighth of an inch. As a result, there is no squeezing force on the ball of the seacock.
The pneumatic actuator in one embodiment utilizes the aforementioned rack and pinion rotator that can operate at any pressure from for instance 35 PSI to 120 PSI. For the application involved, one chooses the lowest pressure specified by the manufacturer that is necessary for rotating the seacock valve. Seacock manufacturers routinely specify a baseline torque for moving the valve so that the pneumatic pressure can be appropriately set. Note that the rotary actuator torque is linear with pressure so that the correct pressure for operating the valve can be easily calculated.
Moreover, in one embodiment, the valve is not over rotated when the stops are taken off with the removal of the handle. Rather, internal stops within the rack and pinion rotator provide for the stops necessary to limit the valve rotation for instance between 0° to 90°. It is noted that rotary actuators are factory set from 0 degrees to 90 degrees, but can also be set from negative 10° to 100°. Since most seacocks operate in the 0 to 90 degree range, setting the stops within the rotary actuator is not required.
Moreover, in order to prevent vibration damage to the seacock valve, a needle valve is positioned between the reservoir and the rotary actuator such that the actuator does not experience the full volume of air when a control valve is opened to supply the air to the rotary actuator.
The rack and pinion rotary actuator is chosen because of its compactness so that it may be easily positioned in hard-to-reach areas which are usually inaccessible by the vessel's operator. Note seacocks exist where there are exhaust lines or intake lines going over the seacocks, or the seacock may be underneath an engine or underneath hatches. Thus most seacocks are relatively inaccessible.
The rotary actuators chosen are extremely compact and will fit in the places where one could extend one's arm to get to a seacock and move the valve stem.
While there are many types of other actuators that could have been used, impact wrench type actuators are not practical because of their torque output. This is because of the large volume of air required and because the air supply must continuously available. Moreover, there are no stops in impact wrench actuators so they must be operated without knowing if the valve is already closed or open.
Other designs include a two air piston design known as a kinematic device which is likewise impractical because of the amount of space utilized and also because the large volume of air requires an exceptionally large reservoir.
As part of the subject invention the system for preventing vessel sinking includes an air reservoir and a number of control valves interposed between the reservoir and the rotary actuators, each of which can individually open or close a seacock by momentarily applying a pulse of air to a port on the rotary actuator. Once the initial pulse of air is delivered to the rotary actuator the control valve returns to a neutral position after which no pneumatic pressure is applied to the rotary actuator.
This has two consequences. First, if one seeks to manually close or open a particular valve one can do so because there is no internal pressure operating on the rotary actuator that would limit seacock valve rotation, all the ports to the rotary actuator being exhausted to the ambient. Secondly, when one utilizes an emergency shutoff valve coupled to the reservoir, the valve connections or circuits are in parallel to those associated with other control valves such that regardless of the position of a seacock valve, when the emergency valve is moved to close all seacocks, a pulse of air is delivered through the actuator's control valve to the appropriate port on each rotary actuator to close the associated seacock valve should it be open. The emergency control valve is also spring loaded back to a neutral position so that it only provides a momentary pulse of air to all of the seacock valve actuators. Thereafter, there is no back pressure on the rotary actuator. This means that this actuator can be again controlled by its control valve regardless of any prior emergency closures.
In one embodiment, a control panel is located between the reservoir and the control valves, with this panel being supplied with an air gauge to indicate the condition of the reservoir.
It is noted that the subject assembly is retrofittable to any valve that has a valve stem extending from the seacock body. Thus any seacock that has a handle can be retrofitted with the subject apparatus. Note that the bolts that hold the seacock in place are used to mount the actuator. As a result, the rotary actuator does not create any undue pressure on the valve itself. Thus, unless one exerts an extraordinary amount of torque one cannot snap off the valve stem by installing the actuator and adapter onto the flange because the flange takes all the load.
Note also that the aforementioned adapter does not apply any force to the valve that is not designed to take. Nor does it affect the friction that the valve was designed with to keep the valve open.
Further, it is noted that by providing the subject retrofit unit one is preventing the ingress of water at its lowest point, thereby eliminating the necessity of providing additional apparatus above this point to close off the flow of water.
Finally, when one closes all of the valves in an emergency shutoff situation it is important to prevent engine operation once the seacock to the engine closed. For gasoline engines it is very common that vessels have a neutral safety switch so that one cannot start up the engine when the safety switch is engaged. In one embodiment there is either an electrical or mechanical linkage to this safety switch from the associated seacock. Also, gasoline engines have switches which cut off the engine if it overheats.
As to diesel engines that do not require electricity for operation, the seacock that supplies the raw sea water intake to the engine may be mechanically linked to a mechanical fuel shutoff for the engine that prevents the engine from running when the associated seacock has been turned off.
Regardless it is part of the subject invention to provide a fail safe system for turning off an engine when its associated seacock has been closed.
In one operative embodiment with a reservoir having a three gallon capacity, seacocks have been opened and closed for a period of 15 cycles without having to recharge the reservoir. This means that in an emergency situation there will be sufficient air supply to be able to close all of the seacocks, while at the same time providing sufficient reserve for normal valve operation.
In summary, a pneumatic seacock closing system is provided in which seacocks can be conveniently closed or in which vessel sinking can be prevented by the ability to pneumatically close all of the vessel's seacocks while at the same time leaving the possibility of selectively overriding seacock closure, with all control valves operating to provide a momentary pulse of air to the rotary actuators and then return to a neutral position, leaving the actuators free for further control. In one embodiment, the subject system is provided in a seacock retrofit package.
These and other features of the subject invention will be better understood in connection with the Detailed Description, in conjunction with the Drawings, of which:
a and 4b illustrate the rack and pinion mechanism for rotating the rotary actuators of
As illustrated in
In order to provide for the subject seacock closing system a control panel 24 is utilized to control the pressure over line 26 from a pressurized air supply 28 coupled to compressor 30.
As will be described, various control valve levers or switches may be utilized to close all of the seacocks in a value closing operation that bypasses or overrides any previous condition of a seacock and its associated actuator.
While the actuators will be described in
It is noted that the pneumatic actuators for each these seacocks are coupled to an air supply by these pairs of lines, with an air pulse on one line opening the associated seacock through the actuation of the associated rotary actuator, and with a pulse on the other of the two lines closing the associated seacock.
Also shown is an engine shutdown module 40 which is mechanically linked to seacock 14 as illustrated at 42. When seacock 14 is closed, module 40 shuts off the fuel supply to engine 20 as illustrated by dotted line 44. In this way when seacock 14 is closed it is impossible to run engine 20 which would otherwise be damaged with the cutoff of cooling water.
While a mechanical linkage is shown for diesel engine shutdown, conventional internal combustion engines may be shut down by solenoids for cutting off the power to the engine.
The cause of vessel sinking may be a failure of the hose or conduit between the associated seacock and the unit to which sea water is applied or from which waste is to be jettisoned. Here it can be seen that seacock 12 is coupled to refrigeration unit 18 by hose or conduit 50, whereas seacock 14 is connected to engine 20 by hose or conduit 52. Likewise a hose 54 connects the outflow of head 22 to seacock 16.
It will appreciated that if there is any failure of these hoses, either due to leakage or due to a hose slipping off an associated nipple either at the seacock or at the device to which it is attached, downflooding of the vessel can occur, sometimes in a rapid fashion.
As will be discussed, a retrofittable system is provided to be able to retrofit each of the seacocks with an actuator which is pneumatically driven to be able to close or open all seacocks, and to be able to selectively control seacock actuation based on the position of the control levers on control panel 24.
In operation, when an operator wishes to leave his or her vessel, the operator actuates an emergency “all close” valve lever to close all seacocks. Thus, when an operator leaves a vessel, he or she can be assured that the vessel is secure against leakage, at least from the seacocks.
When the operator comes aboard, he may wish to open all of the seacocks and this can be accomplished by the same emergency lever so that whatever the condition any of the seacocks in, they will all be turned to an open position.
Because of the parallel series connection of the emergency control valve to the individual control valves that supply momentary air pressure pulses to the actuators of the seacocks, an operator of the vessel can override any previous condition of the emergency valve by applying air pressure to the appropriate opening or closing line for an actuator.
This gives the operator of the vessel a procedure by which he can immediately close all of the seacocks in his vessel as for instance when an emergency situation arises. After closing of all of the seacocks, the operator can investigate the cause of the leak and can selectively open unaffected seacocks.
If in an emergency situation the operator closes all of the seacocks, in one embodiment the seacock associated with the engine is arranged to turn off the engine, be it a diesel engine or a conventional gas engine. Thus when the seacock associated with the engine is closed the engine will not overheat due to a lack of cooling water.
Alternatively, assuming the seacock associated with the engine is not compromised, the sea engine seacock can be re-opened simply by applying an appropriate pulse of air to the associated actuator.
Referring to
Actuator 60 is mounted to seacock 62 through the use of a collar or frame 70 that is bolted to flange 72 of seacock 62, with the collar or flange 70 having a “u” shaped cut out 74 adapted to fit around the cylindrical seacock outflow pipe 76 when the collar or flange 70 is bolted to flange 72 by bolts 78 that are screwed into threaded orifices 80.
Actuator 60 is mounted to flange or collar 70 through bolts 82 such that the mounting of the actuator as a retrofit package to a seacock is simple.
As will be seen, actuator 60 is provided with a pair of inlet ports 84 and 86, with port 84 being provided with a pulse of air indicated by arrow 88 to rotate adapter 64 for closing the associated seacock, and with port 86 provided with a pulse of air 90 to rotate adapter 64 in the opposite direction to open the associated seacock.
Referring to
Referring to
As mentioned hereinbefore, utilization of a rack and pinion type of actuator provides the utmost in simplicity for seacock valve turning in a minimum amount of space and with a minimum amount of mechanical complexity.
Such an actuator is commercially available as model ECV63DA from Rotex Controls in which stops are provided at the factory such that shaft 106 in
As will be appreciated, in order to retrofit the actuator to the seacock, it is often times necessary to remove the handle from the seacock, with the handle in most instances being provided with mechanical stops. However, by utilizing internal stops in the actuator, the seacock valve may be rotated, but not over rotated.
Referring now to
The reason that the emergency valve 122 can override the action of the valves 130, 132 and 134 is because all of the valves in the subject invention are momentary actuation valves in which the opening or closing movement of a lever is only momentary, with the lever being returned to a neutral position by spring biasing or other means.
This means that a pulse of air over a line is momentarily delivered to an actuator after which there is no residual pressure in any of the lines going to the respective actuators.
Moreover, because of the rack and pinion arrangement, once the racks are moved to a position, they stay there, and no additional air pressure is necessary to maintain their position.
As a corollary to the fact that there is no pressure on the actuators when the control valves are in their normal neutral position is the fact that it is easy to manually control any seacock to close or open it's valve because there is no back pressure from the system, once the system has set the valves in an open or closed position.
As can be seen in
Finally, as illustrated at 150 the pressure delivered to the control panel can be continuously monitored such that if the pressure drops below some predetermined level compressor 30 of
In one embodiment a pressurized air tank is on the order of 15 gallons pressurized at 120 psi providing a pressure of 45 psi which can control for instance up to 5 actuators cycling 15 times before recharging.
Referring now to
Since these are momentary actuation valves, the pulses of pressure are only momentarily delivered to open or close the seacocks through the momentary action. If there are no control pulses from valve 120, then valves 130 and 132 operate in the normal fashion.
While the present invention has been described in connection with the preferred embodiments of the various Figures, it is to be understood that other similar embodiments may be used or modifications or additions may be made to the described embodiment for performing the same function of the present invention without deviating therefrom. Therefore, the present invention should not be limited to any single embodiment, but rather construed in breadth and scope in accordance with the recitation of the appended claims.
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Number | Date | Country | |
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20130112902 A1 | May 2013 | US |