Fuel Tank Durability Test System
The APS Fuel Tank Durability Test Stand (Pressure Vacuum System or PVS) simulates pressure and vacuum variations that develop within vehicle fuel tank systems during vehicle operations. Typically, these variations develop due to fuel motion, tank wall motion, engine vacuum changes, and vapor pressure changes. The PVS determines the fatigue life of the fuel tank by alternately applying internal pressure and vacuum to the tank at a given rate. Each cycle, comprised of one pressure and one vacuum run, executes four times per minute until the total number of cycles is completed. Typical specifications are 60 inches of water pressure and 28 inches of water vacuum.
A leak test performed between cycles is completed in user-selectable intervals. This consists of pulling a vacuum to -25 inches of water column and holding it for 60 seconds. Within that time period, the vacuum decay experienced should not exceed the user-defined setting to pass.
The PVS offers both automatic and manual modes of operation. The automatic mode uses predefined settings to complete all test procedures, while the manual mode allows independent control of pressure, vacuum, purge, and leak check settings. Additionally, three thermocouple connections allow the operator to measure temperature in user-selectable areas.