Leak detection system and method

A leak detection system for use with a fluid pump, pump control means for activating and initiating deactivation of said pump, a dispenser, a conduit connecting said pump and dispenser, and a valve in a first portion of said conduit to isolate said pump from said dispenser when a fluid is not being dispensed, said first portion being between said pump and dispenser, said system comprising:

• a. valve seating means, including
• i. a chamber having a pressure responsive first member mounted therein;
• ii. means operated by said first member adapted to forceably seal said valve in response to a predetermined pressure condition in said chamber to ensure no fluid flow past said valve during testing for leakage;
• b. a leak detector including means for delaying deactivation of said pump for a finite predetermined period of time after said pump control means is operated to initiate deactivation of said pump, an enclosure in fluid flow communication with a second portion of said conduit, said second portion being between said valve and said dispenser, and a second member responsive to a fluid condition within said enclosure, said fluid condition within said enclosure being a function of the fluid condition in said second portion of said conduit during said predetermined period of time, and
• c. signal means responsive to said second member to indicate when a predetermined fluid condition in said second portion of said conduit exists.

A leak detection system for use with a fluid pump, a dispenser, and a conduit connecting said dispenser and pump, said system including:

• a. a valve in said conduit to isolate said pump from said dispenser when a fluid is not being dispensed;
• b. valve seating means including
• i. a chamber having a diaphragm mounted therein and dividing said chamber into first and second sections, said first section being in fluid flow communication with a first portion of said conduit, said first portion being between said valve and said dispenser, said second section being in fluid flow communication with a second portion of said conduit, said second portion being between said valve and said pump;
• ii. means responsive to movement of said diaphragm to forceably seat said valve in response to a predetermined pressure differential across said valve to ensure no fluid flow past said valve during testing for leakage;
• c. a leak detector including an accumulator in fluid flow communication with said first portion of said conduit and first means for exerting a predetermined pressure on the fluid in said accumulator, said first portion and in said first section of said chamber when said dispenser is closed;
• d. signal means;
• and
• e. signal activating means responsive to the fluid volume in said accumulator, said signal activating means effecting a change of state of said signal means upon occurrence of a predetermined change in fluid volume in said accumulator after closure of said dispenser.

A method of detecting leaks in a system having a fluid pump, a dispenser, a conduit connecting said pump and dispenser and a valve in said conduit, comprising the steps of:

• a. activating the pump and opening the dispenser to dispense fluid;
• b. closing the dispenser and maintaining activation of the pump;
• c. closing the valve to isolate the pump from the dispenser;
• d. sensing a flow of fluid in the portion of the conduit between the valve and dispenser;
• and
• e. deactivating the pump after a predetermined time period after closing the dispenser.

A method of detecting leaks in a system having a fluid pump, a dispenser, a conduit connecting said pump and dispenser and a valve in said conduit comprising the steps of:

• a. activating the pump and opening the dispenser to dispense fluid;
• b. closing the dispenser;
• c. applying a force on said valve from an energy soorce external to said valve to forceably seal the valve;
• d. applying a predetermined pressure on the fluid in the portion of the conduit between the valve and dispenser within a predetermined period of time after the dispenser is closed;
• e. sensing a flow of fluid in said portion of the conduit;
• and
• f. energizing signal means if said flow of fluid is greater than a predetermined amount.