a vapor recovery and pressure management system for a vehicle refueling facility includes two rotary vane pumps and a hydrocarbon - stripping membrane between the pumps . one pump draws vapor from a storage tank as well as from refueling nozzles , while the other pump draws vapor from the membrane and discharges the vapor back into the tank . a controller controls both pumps to maintain a slight vacuum in the tank , thereby preventing leakage of hydrocarbons from the tank to the atmosphere . clean air from the membrane is exhausted , preferably through a charcoal canister , and a hydrocarbon sensor monitors for the presence of undesirable hydrocarbons in the clean air exhaust . one or more liquid drop outs are provided for separating liquid from the hydrocarbon vapor and returning the liquid to the tank along with the vapor , preferably before the liquid is sent to the membrane , to thereby increase efficient fuel recovery and to protect the membrane from undesirable contact with liquid .