Fluent material handling – with receiver or receiver coacting mea – Filling means with receiver or receiver coacting means – Flexible hose terminal with receiver engaging means
Reexamination Certificate
2000-03-04
2001-10-30
Jacyna, J. Casimer (Department: 3751)
Fluent material handling, with receiver or receiver coacting mea
Filling means with receiver or receiver coacting means
Flexible hose terminal with receiver engaging means
C137S001000, C137S487000, C137S492500, C137S596140, C137S068140
Reexamination Certificate
active
06308753
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a system for loading and unloading fluid tanks containing hazardous fluids, and more particularly to such a system in which one of the tanks is mounted on a roadway vehicle and the other tank is a fixed storage tank.
BACKGROUND OF THE INVENTION
Hazardous fluid products are transferred between a fixed storage tank and a tank on a roadway vehicle. Normally, a flexible transfer hose assembly is detachably coupled to the tank at the loading or unloading site. The opposed ends of the transfer hose assembly are normally fitted with rotatable couplings that are threaded onto male pipe ends extending from the tanks for connection of the flexible hose assembly. It is possible under certain conditions during transfer of the hazardous fluid product that the flexible hose of the hose assembly may separate from the couplings, or the flexible hose may fail, resulting in release of the hazardous product to atmosphere. Such a release of the hazardous product, such as propane or anhydrous ammonia, for example, could result in a life threatening situation.
While back check valves adjacent the tanks may, in many instances, stop the flow of the hazardous product upon failure of the flexible hose or couplings, pumps or other inline devices at the unloading tank in many instances will restrict the effectiveness of the excess flow valve typically installed in the outlet piping on the vehicle. It is necessary that flow of the hazardous fluid product be stopped at each of the tanks upon failure of the hose assembly in order to stop discharge of the hazardous product into the atmosphere.
It is desired that a safety system be provided for automatically shutting off the flow of product for each tank without human intervention upon a failure in the hose assembly between the tanks.
SUMMARY OF THE INVENTION
The present invention is directed to a system for loading and unloading fluid tanks containing hazardous fluids, and particularly an apparatus and method for transferring a hazardous fluid product through a flexible hose assembly detachably connected between a tank of a roadway vehicle and a fixed storage tank. The hazardous fluid product in one embodiment is transferred from the roadway vehicle tank to the storage tank and in another embodiment the hazardous fluid product is transferred from the storage tank to the roadway vehicle tank.
A gas operated product supply valve from the tank being unloaded is maintained in an open position during normal product transfer by pressurized gas to permit product flow to the tank being loaded. A gas control valve is mounted between a gas source for the gas operated product supply valve and the product supply valve to control the supply of pressurized gas to the product supply valve. The gas control valve senses the product fluid pressure in the flexible transfer hose and is effective in the event a predetermined low pressure is sensed in the transfer hose to exhaust gas from the gas operated product supply valve to effect movement of the product supply valve to a closed position to stop product flow from the tank being unloaded. A back check valve for the tank being loaded is effective to stop any back flow from the tank being loaded.
The gas control valve has an inlet port in fluid communication with a pressurized gas source, an outlet port in fluid communication with the gas operated product supply valve and a vent between the ports. A piston valve member in the gas control valve is responsive to fluid pressure from the product flowing through the flexible hose and is movable between a pressurized normal operating position and a non-pressurized emergency position. In the pressurized normal operating position, the piston valve member is actuated and effective to block fluid communication between the inlet port and vent, and to permit the supply of pressurized gas to the gas operated product supply valve for opening of the product supply valve during normal operation for product transfer between the tanks. In the emergency position, the piston valve member is responsive to zero or low fluid pressure from the product flowing through the flexible hose to permit fluid communication between the inlet port and the vent for exhaust of pressurized gas from the gas operated product supply valve when the fluid pressure of the product flowing through the flexible hose is below a predetermined minimal pressure.
A sensing line in the flexible hose extends to a piston sensing chamber for the piston valve member to communicate product pressure to the piston valve member. Thus, in the event the product transfer hose is separated from end couplings, or fails, and the product is being discharged into the atmosphere, a low pressure in the transfer hose is sensed by the gas control valve to exhaust gas from the gas operated product supply valve for moving the product supply valve to a closed position to stop product flow automatically from the tank being unloaded.
The fluid sensing line has a small diameter internal portion extending from a fitting on the hose assembly within the flexible hose for sensing the fluid pressure resulting from product flow in the hose. A flexible external portion of the sensing line extending from the fitting is detachably connected to the gas control valve to provide fluid communication with the sensing chamber adjacent the piston valve member of the gas control valve. Upon a break or separation in the hose, a rapid reduction or decrease in the fluid pressure of the hose results which is sensed by the gas control valve for movement of the piston valve member to an exhaust position for exhausting the gas from the gas operated product supply valve to effect closing or shut-off of the product supply valve. The internal portion of the product sensing line in the transfer hose comprises a relatively small diameter tube having an open end and preferably formed of a plastic material of a diameter of about ¼ inch. Any failure of the sensing line results in a reduction or decrease of the fluid pressure sensed by the gas control valve resulting in the exhaust of pressurized gas to the gas operated product supply valve.
It is an object of this invention to provide a safety system for a detachable flexible hose assembly coupled between a storage tank and a tank of a roadway vehicle for transferring a hazardous fluid product between the tanks so that product flow is stopped in both directions without human intervention upon a hose or coupling separation or failure.
It is a further object of the invention to provide such a safety system in which the tank for the hazardous fluid product being unloaded has a gas operated product supply valve which is maintained in a normal operating open position by pressurized gas and moves to a closed position to stop flow of hazardous product from the tank upon an exhaust of gas from the gas operated product supply valve.
Another object of the invention is the provision of a gas control valve to control the supply of pressurized gas to the gas operated product supply valve for the opening and closing of the gas operated product supply valve upstream of the flexible hose.
A further object of the invention is the provision of a passive shut-off means for stopping the flow of product from the tank being unloaded without the need for human intervention within twenty (20) seconds of the occurrence of an unintentional release caused by separation of the discharge hose or coupling.
Other objects, features, and advantages of the invention will be apparent from the following specification and drawings.
REFERENCES:
patent: 3016928 (1962-01-01), Brandt
patent: 4520844 (1985-06-01), Finkelstein et al.
patent: 4957238 (1990-09-01), Kreuter
patent: 5921266 (1999-07-01), Meyer
patent: 6012482 (2000-01-01), Nelson et al.
Two advertising sheets of Lifeline Technologies, Inc. entitled “Smart-Hose”, considered as prior art, dates of publication unknown.
Nimberger Spencer M.
Ward Robert L.
Browning Bushman
Jacyna J. Casimer
PGI International Ltd.
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