Custom-designed rotary valves from Omnifit have helped the manufacturer of a DNA analysis instrument solve a seemingly intractable problem. The instrument, which uses very high-viscosity fluids, needed inert valves with sufficient sheer force to cut through the fluid, acting as shut-off valves. Solenoid valves were found to have insufficient force for the exacting application. The solution from Omnifit was a 1mm-bore custom-designed rotary valve with a stainless steel rotor for torsional strength, a Tefzel liner for chemical inertness, and a Peek body for rigidity. The shape of the rotor was carefully profiled to give a clean cut through the fluid ensuring an instant start/stop to the flow. The valve can operate up to very high pressures (1000lb/in2) and is controlled by TTL or RS232 protocols.
