Brownell has introduced a range of ultra high flow performance relief valves with standard sizes of 25 to 200mm. An unusual operating characteristic for this pressure relief valve is proportional decrease in back pressure after the relief valve has opened at the set pressure and increased flow is required. This allows a high increase in gas flow and makes the valves suitable for over pressures in pipelines, pressure vessels, storage vessels, equipment containers and safety relief applications The standard specification for pressure settings is from 0.5 to 5psi for opening pressures and vacuum relief. The pressure relief valve can operate in aggressive environments including corrosive chemicals, driving rain, and low and high temperatures. A weather and impact shield provides further mechanical and physical protection. Additional features options include a debris filter, EMC screening and a manual relief over-ride.