Kelly Pneumatics Proportional Valves offer excellent proportional flow performance using original, patented technology. Our proportional valve design includes one flexing part with virtually no friction, giving each valve an exceptionally long life cycle. The smooth, accurate, low hysteresis performance made capable by this design offers significant improvements over traditional solenoid valves. By incorporating this technology into every valve we offer, each performs with incredible accuracy and consistency. Kelly Pneumatics offers a wide variety of proportional valve sizes with varying flow performances to meet many specific requirements.