The newly redesigned Continuous Backflush screen changer from PSI-Polymer Systems Inc., Hickory, N.C., has twice the screen area of PSI’s previous CSC/BF unit. Both have two pistons, but in the older model each piston pushed a single screen in and out for backflushing and screen changing. The new model splits the flow through each piston into two screened filter cavities, for a total of four. Doubling the screen area allows 25 times longer screen life because it reduces backpressure, PSI claims. The new unit comes in five standard sizes from 1000 to 10,000 lb/hr.