Piston Sensed, Back Pressure Regulating Valves The JBPH Series is a piston operated back pressure regulator. The 0.5 Cv (0,43 Kv) offers increased flows across its 6000 psi (414 bar) inlet range, while the KEL-F soft seat provides ANSI Class VI shutoff. USDA and FDA approved soft goods available upon request. Research and sampling systems for corrosive and specialty gases Gas chromatography Flame ionization detectors Industrials controls