The Borealis Group, a European producer of polyethylene (PE) and polypropylene (PP), has turned to safety relief valves from Tyco Valves and Controls to safeguard equipment and personnel at its Swedish plant in Stenungsund. With six major manufacturing sites across Europe, the Borealis Group produces over 3 million tonnes of PE and PP each year. The 150 safety relief valves are installed at the ethylene cracking plant, which produces ethylene and propylene by “cracking” refinery-derived petroleum products at high temperatures. These products are then used in the Borealis Polyethylene plant which produces granulats, as well as supplying chemical and coating manufacturers in the area, such as Akzo Nobel Surface Chemistry, Hydro Polymers and Neste Oxo. The Anderson Greenwood/Crosby valves are installed at various points in the process and are in contact with a range of media from hydrocarbons to steam, water, caustic and air. Flow rates can reach over 100000kg/hr with temperatures from –107°C to 550°C and pressure from 3.5 to 117 barg. Process safety relief valves are activated in the event of pressure build-up caused by a blockage in the pipeline. Additional valves are installed on the boiler and release excess pressure caused by steam and water expansion during firing.
