VST Coaxial Balance Products Overview

What are Coaxial Balance Systems?

Balance systems through the balancing of natural forces. The delivery of fuel to the vehicle fuel tank creates a partial positive pressure within the vehicle tank. At the same time the pumping of fuel from the storage tank creates a partial negative pressure (vacuum) within the storage tank. Once there is a vapor path between the two, the vapors will balance and flow naturally from the positive to the negative.

The vapor path is created by modifying the nozzle, hose and dispenser. A coaxial boot is added to the nozzle which fits over the spout, seals to the side of the vehicle and captures the vapors venting from the fill neck while fuel is being dispensed through the spout. A coaxial hose is added which conveys gasoline to the nozzle through the inner path while vapors travel through the outer. There is a splitter either in or on the dispenser which directs the fuel being pumped through the coaxial hose to the nozzle at the same time the vapors being returned are directed through the vapor return line back to the storage tank.