GB1505023A - Liquid dispensing and vapour recovery apparatus - Google Patents

Abstract

1505023 Liquid dispensing apparatus WEIL-McLAIN CO Inc 31 March 1976 [31 March 1975 4 April 1975] 12990/76 Heading B8N A liquid dispensing apparatus, particularly for petrol, comprises a conduit 22, 22a, 78 from a storage tank 10 to a dispenser 44, a second conduit 80, 24, Fig. 2, along which a portion of the liquid from the first conduit is diverted back to the tank and a third conduit 60 along which liquid vapour is sucked into the second conduit. The diverted liquid is directed through a Venturi 84 which creates a reduced pressure zone which is connected via a valve 116 to the third conduit 60 which extends from the dispenser 44. The valve 116 is controlled by a diaphragm 112 subjected to pressure upstream and downstream of a Venturi 102 through which the liquid to be dispensed flows. A valve 92 is spring-biased to close the second conduit 80 until the liquid is being dispensed. The valve 92 has a head which co-operates with a seat in the first conduit which allows flow into the conduit 78 when the stem of the valve closes the second conduit to equalize the pressure. When dispensing is initiated the drop in pressure in the conduit 78 causes the valve 92 to open and allow liquid to be diverted to the second conduit and create a back pressure in the Venturi 84. In a second embodiment a check valve 174, Fig. 3, is provided in the vapour return conduit 188 controlled by a Venturi 184 in the second conduit 180, 24 along which liquid is diverted.