Safety device for a fluid storage tank, related systems and methods

Abstract

A safety device for a fluid storage tank having a first port for filling the tank with fuel oil and a second port for allowing airflow therethrough is disclosed. The safety device includes a tubular body having a first open end and a second open end connectable to the second port, and a flow check valve contained within the tubular body and configured to remain open when air flows through the safety device and configured to close based on a predetermined fluid force of the fuel oil through the safety device. Related systems and methods are also disclosed.

What is claimed is: 
     
         1 . A storage tank safety system, comprising:
 a storage tank configured to store a fluid having a first port used to fill the tank with the fluid and a second port used as an air vent; and   a safety device connected at the second port having a fluid stop configured to permit air to vent and configured to prevent the fluid from flowing through the second port.   
     
     
         2 . The storage tank safety system of  claim 1 , wherein the fluid is fuel oil. 
     
     
         3 . The storage tank safety system of  claim 1 , wherein the safety device is a flow check valve and the flow check valve is one of a stem-type check valve and a flapper-type check valve. 
     
     
         4 . The storage tank safety system of  claim 1 , further comprising a fill alarm positioned between the second port and the safety device. 
     
     
         5 . The storage tank safety system of  claim 4 , wherein the fill alarm is a whistle-type fill alarm. 
     
     
         6 . The storage tank safety system of  claim 5 , wherein said safety device comprises:
 a stop positioned centrally between a first open end and a second open end of the safety device and extending inward from an outer edge of said body and along a circumference of said body, said stop defining a hole located centrally therethrough; and   a stem positionable between a first position within said hole to allow airflow in two directions through said hole and a second position to prevent fluid flow in a direction out of said tank through said hole,   wherein a weight of the stem is determined to permit the air to flow through the safety device and prevent the fluid from flowing through the safety device.   
     
     
         7 . The storage tank safety system of  claim 6 , wherein said whistle-type fill alarm reduces the flow of the air and fluid into the safety device. 
     
     
         8 . The storage tank safety system of  claim 7 , wherein the stem is configured to operate in the first and second positions based on the reduction of the flow of the air and the fluid produced by the fill alarm. 
     
     
         9 . The storage tank safety system of  claim 8 , wherein the fluid force required to move the stem from the first position to the second position is produced by a fluid flow into the first port of approximately one gallon per second. 
     
     
         10 . The storage tank safety system of  claim 1 , wherein said safety device comprises:
 a stop positioned centrally between a first open end and a second open end of the safety device and extending inward from an outer edge of said body and along a circumference of said body, said stop defining a hole located centrally therethrough; and   a stem positionable between a first position within said hole to allow airflow in two directions through said hole and a second position to prevent fluid flow in a direction out of said tank through said hole,   wherein a weight of the stem is determined to permit the air to flow through the safety device and prevent the fluid from flowing through the safety device.   
     
     
         11 . The storage tank safety system of  claim 10 , wherein the safety device further comprises a flow reducer positioned between the second port and the stem to reduce the flow of the air and fluid through the safety device, and wherein the stem is configured to operate in the first and second positions based on the reduction of the flow of the air and the fluid produced by the flow reducer. 
     
     
         12 . A safety device for a fuel oil storage tank having a first port for filling the tank with fuel oil and a second port for allowing airflow therethrough, the safety device comprising:
 a tubular body having a first open end and a second open end connectable to the second port; and   a flow check valve contained within the tubular body and configured to remain open when air flows through the safety device and configured to close based on a predetermined fluid force of the fuel oil through the safety device.   
     
     
         13 . The safety device of  claim 12 , wherein said flow check valve comprises:
 a stop positioned centrally between said first and second open ends and extending inward from an outer edge of said body and along a circumference of said body, said stop defining a hole located centrally therethrough; and   a stem positionable between a first position within said hole to allow airflow through said hole and a second position to prevent fluid flow through said hole,   wherein the weight of the stem is determined to permit the air to flow through the safety device and prevent the fuel oil from flowing through the safety device.   
     
     
         14 . The safety device of  claim 12 , wherein the predetermined fluid force is produced by a fuel oil flow into the first port. 
     
     
         15 . The safety device of  claim 12 , further comprising a flow reducer positioned between the second port and the flow check valve to reduce the flow of the air and fluid through the safety device. 
     
     
         16 . The safety device of  claim 15 , wherein the stem is configured to operate in the first and second positions based on the reduction of the flow of the air and the fluid produced by the flow reducer. 
     
     
         17 . The safety device of  claim 16 , wherein the fluid force required to move the stem from the first position to the second position is produced by a fluid flow into the first port of approximately one gallon per second. 
     
     
         18 . The safety device of  claim 15 , wherein the flow reduction orifice is a whistle-type fill alarm. 
     
     
         19 . A method for preventing fluid spillage from a storage tank having a first port for filling the tank with fluid and a second port for allowing airflow therethrough, the method comprising the steps of:
 providing a fill alarm;   attaching the fill alarm to the second port;   providing a flow check valve; and   attaching the flow check valve to the fill alarm.   
     
     
         20 . The method of  claim 19 , wherein the flow check valve is designed to remain in an open position during a consumption and filling operation to permit airflow therethrough and remain in a closed position during a filling operation when fluid flows into the flow check valve.