Pilot-Operated, Superior Accuracy The Mark 57 Series pilot operated back pressure regulator is designed to accurately control pressure to 90% of its rated flow capacity with only a small deviation from setpoint, providing accuracy that approaches that of controller-operated valves and should be considered on most critical applications. This versatile pilot operated back pressure regulator valve features Jordan Valve's proprietary sliding gate seat technology, which provides straight-through flow for reduced turbulence, quiet operation, fast response, and tight shutoff. Available in sizes ranging from 1/2" to 6" (DN15 to DN150) with Cv values up to 395 (Kv up to 340), the Mark 57 can handle a wide variety of applications including steam, air, gas, liquids, and chemicals. The pilot operated back pressure regulator features a stainless steel diaphragm and offers setpoint ranges from 10 to 185 psi (0.7 to 12.8 bar), with high turn-down ratios up to 50:1. Body materials include ductile iron, carbon steel, stainless steel, and cast iron, with various end connection options including threaded, flanged, socket weld, and butt weld configurations. The Mark 57 carries both EC Declaration of Conformity/PED certification for sizes 1-1/4" to 6" and CRN (Canadian Registration Number) approval for the full size range from 1/2" to 6".