Barksdale Control Products’ 9020 Series Shear-Seal Directional Control Valves feature both interflow and non-interflow technology and easy panel mounting, purpose made for pneumatic valve actuators, gas manifold controls and manual control of two-position cylinders.
Shear-Seal valves offer much lower pressure drop and control fluid at a much higher velocity than other valve technologies.
Interflow valves allow a small amount of fluid to flow from Pressure A and B ports to the return port through a small clearance between the motor and the body. This occurs whenever the valve is shifted from one position to another or when the valve is being used for throttling.
Interflow is not leakage, nor does it occur when the valve is fully engaged. Instead, the purpose of interflow is to reduce hydraulic shock or “water hammer” that can occur when a valve is closed rapidly. The interflow acts as a cushion when fluid flow is stopped in the system.
Non-interflow valves use a smaller flow passage to completely cover the space between the pressure seal and rotor. Non-interflow valves may be required when precise control of cylinder is needed and the small settling associated with interflow valves cannot be tolerated.
Non-interflow valves have a much lower flow rate than interflow valves with the same port size, and require higher force to actuate.
Pressure drop in 9020 series control valves is controlled due to smooth internal passages and transitions within the valves to keep turbulent fluid flow to minimum. This translates to less heat build-up and high pressures available to perform the required work.
High-velocity fluid control allows a smaller valve to perform jobs typically reserved for larger valves, saving space and component costs. The recommended fluid velocity for Barksdale valves is 30 ft/s for continuous operation, although the valve can easily handle up to 60 ft/s fluid flow for intermittent duty.
Valves operate via pneumatic or hydraulic pressure from 150 to 350 psi. The anodized aluminum body can withstand back pressure up to 250 psi at the return port, up to 150 percent of the working pressure without damage to the valve, and a burst pressure up to 250 percent the working pressure.
For more information about Barksdale’s 9020 Series Shear-Seal Control Valves, contact our experts today!