COMPLIANCE INFO_1997-2006 - Laserfiche WebLink

Home Browse Search

The FE Petro STP -MLD leak detector is a three position, pressure - sensing, piston operated valve designed to continuously monitor Lie piping by indicating any leakage in the piping between the discharge and submersible pump and the solenoid valve in a service station disperser. When the submerged pump is turned on after the system preszu:e has dropped significantly below the 1. The Tripped or Bottom Position When the system is less than 1 psi.:^e piston and poppet are in the "bottom' or "tripped- position. In th'.s position of the poppet. product flow. through the horizontal hole in the pc�p- pet and around the metering pin at a rate of approximately 2 GPAI flow into the delivery line when the submersible pump is running. In normal operations the piping remains full of fluid and when the submersible pump is turned on, with a floe• rate of 2 GPAI through the poppet, pressure builds rapidly and the poppet moves to the leak sensing position. normal static system pressure, three GPH (at 10 psi) is metered through the STP -AILD into the piping system. If a leak is present that equals or exceeds this amount, as much product escapes from the system as is metered through the STP -AILD. Under this condition, pressure cannot b.:ild up in the piping system. When a nozzle is opened. a poppet in the STP -AILD moves to a position that rest::cts the flow to 2 2. Leak SenIzing Position In this position the sys:em pressure ..as increased to apprr.:iniately 12 psi and all the Dow n zt travel around the metering pin which limits it to approximately a 3 GPH rate (at 10 psi �. If there is a leak in the system which Noill allow leaka_e to exceed this amount. the line pressure will not build beyond this point and the valve «ill remain in the leak sensing position xith the main flow blocked. If there is an attempt to dispense while the vale is in this posi- tion, the line pressure vvil] drop to less than 1 psi, the piston x ill respond, and the poppet \+ill return to Position 1 where 2 GPM will floe• to the dispensers. Leaks smaller than 3 GPH will be indi- cated by the STP -AILD taking longer than three seconds to open completely because some of the Dow leaks out of the system and the rest builds pressure. If there is no leakage in the system, the small flow around the metering pin increases the line pressure and in approximately three seconds the piston will move the poppet to Position 3. GPM. This is the indication to the operator that a leak is present. if there are no leaks, pressure rapidly builds in the system forcing the STP -AILD to open to the full -flow position. In a system with no leak:.:: takes approximately three second_ a complete test. No further line les: takes place until the line pressure drops significantly below the norrl.t static system pressure. A' M, 3. Ton -Leak or Full Flow Position This position allows full flow. Tl:e poppet will remain in approxima:e'.Y this position as long as the System pressure remains at about the pumping pressure. If the pre: sure in the system drops when the pump is turned off, either due to thermal contraction of the product or due :o a leak, the piston moves downward and the poppet engages and seals inside the cage at about 3 psi, or approxi- mately 10 feet of head, in gasoline. .Any time the pump is turned on after the seal on the poppet is inside the cage, a line test will be performed. FE Petro, Inc. ■ 4805 Voges Road P.O. Box 139 ■ 'McFarland, \WI 53558 (608) 838-8786 a Favi: (608) 838-6433