Deadtight-Sealed Air Suspension Valve Is Maintenance-Free

Engineers at Barksdale Controls have perfected an exceptionally compact, lightweight valve for use in approximately 70% of the air suspension systems used on tractor-trailer rigs in North America. In these systems, air bags control ride height and load compensation, with constant pressure maintained by an engine-driven air compressor. At the heart of the system is an air leveling valve actuated by mechanical linkage, admitting more air when the distance between the axle and the frame decreases to less than permissible minimum dimension. The same valve exhausts air when the distance becomes excessive. In the past, this leveling valve has always been the weakest link in the system. Constant fill and exhaust operations represents rough duty for a valve. If excessive leakage occurs, fuel consumption will increase. If the valve fails, so does the entire air suspension system.

Of rotary design and containing only one moving part, the Barksdale Controls valve relies on lapped surfaces to affect a seal. Design is such that the medium (compressed air) does not flow across the sealing surfaces, but directly through the inside diameter of the seal. Thus normal contaminants in the air flow do not cause seal leakage. Qualification testing indicates that the valve is capable of more than 100 million cycles. A major class 8 truck manufacturer that installed the Barksdale air suspension valve on 19 tractors reported zero valve failures after 400,000 mile over-the-road operation.

Valve operation is affected by the relative movement of two circular, overlapping ports moving relative to each other. A fast-flow dump port permits rapid (10 sec) depressurization of the system prior to driving a tractor away from a parked trailer. The valve rotor and pressure seals tend to continue to lap-in with use, making it possible for the valve to "heal" small scratches in the sealing surfaces.

For more information, contact Barksdale, Inc., 3211 Fruitland Ave., Los Angeles, CA 90058-0843. 800-835-1060. Circle 790.