Patt filtration continuous rotary backflush and plastic PATT FILTRATION - Continous Filtration Systems with Constant Pressure Drop PATT Filtration was established in 1986 in St-Eustache, Canada. Since then, we have grown to be a major competitor in the filtration systems industry. PATT Filtration is now a division PATT Technologies. PATT Filtration is one of the industry’s leading suppliers of constant pressure, continuous screenchangers. The company’s Rotary III is the only continuous screenchanger manufactured in North America and backed by a performance guarantee. Patt Filtration guarantees no downtime during screen changes. Its custom tailored solutions enable clients to filter any engineering polymer with pressures up to 12000 psi and temperatures up to 650°F.