Double Block And Bleed Ball Valve Forged Trunnion Mounted Ball Valve-A105N-2500LB. The versatility of the Double Block and Bleed ball valve makes it an essential component in various industries, including oil and gas, chemical processing, and water treatment. By providing a reliable means of isolating sections of piping and safely venting trapped fluids, these valves play a crucial role in maintaining system integrity and preventing hazardous situations.