Alco Hi-Tek, the specialist DBB division of the Alco Valves Group, has introduced the Twin-Blok II range of Double Block and Bleed valves (DBBs). Alco’s designs have been widely used within the offshore and petrochemical industries since the early 1980s. The latest Twin-Blok II design, which won an award from ASME (American Society of Mechanical Engineers), delivers crystal clear advantages to all users of 3/8” to 4” bore, low and high-pressure pipeline or instrumentation Double Block & Bleed Valves. Most other DBB manifold designs inherently have a greater chance of leakage due to the greater number of pressurised joints within the construction. These joints are normally a means of access to the internal components of the valves (seats, balls, stems etc.), the way in which the valve parts are inserted into the body construction upon assembly at the factory. Once the “guts” of the valves are fitted the joints become redundant serving only as potential leak paths or another pressure seal that may require maintenance.
