This year, Cheshire-based Oliver Twinsafe celebrates its 30th anniversary, 25 years of which have been dedicated to developing and improving double block and bleed systems. Throughout the past years the company has seen significant growth in demand for its cartridge-style, standard-length double block and bleed valve. As with all Oliver Twinsafe valves, the cartridge-style, standard-length double block and bleed valve has been approved by the Lloyd’s Register quality assurance.