These valves are constructed in such way that their entrance and exit are on the pipeline axis(axial type). Increased pressure on the pipeline opens the valve through its membrane, and the excess of fluid returns to the provided places. Pressure relief valves are made ofstainless steel, steel, brass and platic. They are used for pressure grades up to Pmax=40bar, acids, alkalis, water and technical gases. They are produced in sizes from DN10 to DN25.